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1.  Protein biomarkers in cystic fibrosis research: where next? 
Genome Medicine  2010;2(12):88.
Cystic fibrosis is one of the most common life-limiting inherited disorders. Its clinical impact manifests chiefly in the lung, pancreas, gastrointestinal tract and sweat glands, with lung disease typically being most detrimental to health. The median age for survival has increased dramatically over the past decades, largely thanks to advances in understanding of the mechanisms and consequences of disease, leading to the development of better therapies and treatment regimes. The discovery of dysregulated protein biomarkers linked to cystic fibrosis has contributed considerably to this end. This article outlines clinical trials targeting known protein biomarkers, and the current and future contributions of proteomic techniques to cystic fibrosis research. The treatments described range from those designed to provide functional copies of the mutant protein responsible for cystic fibrosis, to others addressing the associated symptoms of chronic inflammation. Preclinical research has employed proteomics to help elucidate pathways and processes implicated in disease that might present opportunities for therapy or prognosis. Global analyses of cystic fibrosis have detected the differential expression of proteins involved in inflammation, proteolytic activity and oxidative stress, which are recognized symptoms of the cystic fibrosis phenotype. The dysregulation of other processes, such as the complement and mitochondrial systems, has also been implicated. A number of studies have focused specifically on proteins that interact with the cystic fibrosis protein, with the goal of restoring its normal proteostasis. Consequently, proteins involved in synthesis, folding, degradation, translocation and localization of the protein have been identified as potential therapeutic targets. Cystic fibrosis patients are prone to lung infections that are thought to contribute to chronic inflammation, and thus proteomic studies have also searched for microbiological biomarkers to use in early infection diagnosis or as indicators of virulence. The review concludes by proposing a future role for proteomics in the high-throughput validation of protein biomarkers under consideration as outcome measures for use in clinical trials and routine disease monitoring.
PMCID: PMC3025430  PMID: 21167082
2.  A 2-year-old girl with co-inherited cystic fibrosis and sickle cell-β+ thalassemia presenting with recurrent vaso-occlusive events during cystic fibrosis pulmonary exacerbations: a case report 
This is the first published report of a young girl with co-inherited sickle cell-β+ thalassemia and cystic fibrosis. Although a small subset of patients with co-inherited cystic fibrosis and other hemoglobinopathies have been reported, this patient developed early hematologic and pulmonary complications that were more severe than the previous cases. To assess pulmonary co-morbidities, we used infant pulmonary function testing through the raised volume rapid thoracoabdominal compression technique as both an established study of early cystic fibrosis and also as a newer study of mechanism for early sickle cell lung disease. This further serves as the first report of the raised volume rapid thoracoabdominal compression technique to determine raised volume forced expiratory flows and fractional lung volumes in a patient with a hemoglobinopathy.
Case presentation
A 2-year-old African-American girl with co-inherited cystic fibrosis and sickle cell-β+ thalassemia developed severe hematologic complications (recurrent vaso-occlusive events, hepatic sequestration, and acute chest syndrome) during periods of cystic fibrosis pulmonary exacerbations and weight loss. Because cystic fibrosis and sickle cell-β+ thalassemia both confer distinct patterns of pulmonary disease, infant pulmonary function testing with the raised volume rapid thoracoabdominal compression technique was used to define respiratory pathophysiology and guide treatment options. Infant pulmonary function testing data demonstrated moderate-to-severe lower airways obstruction, moderate air trapping, and no evidence of restrictive lung disease.
Infant pulmonary function testing with the raised volume rapid thoracoabdominal compression technique guided therapy in this patient with cystic fibrosis and sickle cell-β+ thalassemia. Although this is an original case report on a unique patient, this case highlights the need to evaluate early respiratory pathophysiology in a broader population of young patients with hemoglobinopathies and screen those at risk for early pulmonary co-morbidities.
PMCID: PMC3750320  PMID: 23890029
Acute chest syndrome; Cystic fibrosis; Hemoglobinopathy; Infant pulmonary function testing; Raised volume rapid thoracoabdominal compression; Sickle cell; Thalassemia; Vaso-occlusive event
3.  MMP1 and MMP7 as Potential Peripheral Blood Biomarkers in Idiopathic Pulmonary Fibrosis 
PLoS Medicine  2008;5(4):e93.
Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrotic lung disease associated with substantial morbidity and mortality. The objective of this study was to determine whether there is a peripheral blood protein signature in IPF and whether components of this signature may serve as biomarkers for disease presence and progression.
Methods and Findings
We analyzed the concentrations of 49 proteins in the plasma of 74 patients with IPF and in the plasma of 53 control individuals. We identified a combinatorial signature of five proteins—MMP7, MMP1, MMP8, IGFBP1, and TNFRSF1A—that was sufficient to distinguish patients from controls with a sensitivity of 98.6% (95% confidence interval [CI] 92.7%–100%) and specificity of 98.1% (95% CI 89.9%–100%). Increases in MMP1 and MMP7 were also observed in lung tissue and bronchoalveolar lavage fluid obtained from IPF patients. MMP7 and MMP1 plasma concentrations were not increased in patients with chronic obstructive pulmonary disease or sarcoidosis and distinguished IPF compared to subacute/chronic hypersensitivity pneumonitis, a disease that may mimic IPF, with a sensitivity of 96.3% (95% CI 81.0%–100%) and specificity of 87.2% (95% CI 72.6%–95.7%). We verified our results in an independent validation cohort composed of patients with IPF, familial pulmonary fibrosis, subclinical interstitial lung disease (ILD), as well as with control individuals. MMP7 and MMP1 concentrations were significantly higher in IPF patients compared to controls in this cohort. Furthermore, MMP7 concentrations were elevated in patients with subclinical ILD and negatively correlated with percent predicted forced vital capacity (FVC%) and percent predicted carbon monoxide diffusing capacity (DLCO%).
Our experiments provide the first evidence for a peripheral blood protein signature in IPF to our knowledge. The two main components of this signature, MMP7 and MMP1, are overexpressed in the lung microenvironment and distinguish IPF from other chronic lung diseases. Additionally, increased MMP7 concentration may be indicative of asymptomatic ILD and reflect disease progression.
Naftali Kaminski and colleagues find increased levels of specific proteins in the bloodstream of individuals with idiopathic pulmonary fibrosis, and suggest that these proteins may ultimately provide a biomarker for the disease.
Editors' Summary
Idiopathic pulmonary fibrosis (IPF) is a serious disease in which the lungs become progressively scarred or thickened for unknown reasons. In healthy people, air is taken in through the mouth or nose and travels down the windpipe into tubes in the lungs called the airways. Each airway has many small branches that end in alveoli, tiny air sacs with thin walls that are surrounded by small blood vessels called capillaries. When air reaches the alveoli, the oxygen in it passes into the bloodstream and is taken to the organs of the body to keep them working. In IPF, the alveoli and the space around them (the “interstitial” area) gradually become scarred and thickened, which stops oxygen's movement into the bloodstream. When only small areas of the lung are scarred, IPF may cause no symptoms. But, as more of the lung becomes damaged, IPF eventually causes breathlessness, even when resting. There is no effective treatment for IPF, although steroids and drugs that suppress the body's immune system are often tried in an attempt to slow its progression. On average, half of the people with IPF die within three years of diagnosis, often from respiratory or heart failure.
Why Was This Study Done?
It can be difficult to diagnose IPF—there are many lung diseases with similar symptoms, including numerous other interstitial lung diseases—and currently, physicians can only follow the progression of IPF by repeatedly testing their patients' lung function or by doing multiple chest X-rays. If proteins could be identified whose level in blood indicated disease activity (so-called “peripheral blood biomarkers”), it would be easier to diagnose and monitor patients. In addition, the identification of such biomarkers might suggest new drug targets for the treatment of IPF. In this study, the researchers look for peripheral blood biomarkers in IPF by using a “multiplex analysis” system to measure the level of several proteins in patient blood samples simultaneously.
What Did the Researchers Do and Find?
The researchers measured the levels of 49 plasma proteins (plasma is the fluid part of blood) in 74 patients with IPF and 53 healthy people (controls) and used a technique called “recursive partitioning” to define a five-protein signature that distinguished patients from unaffected study participants (controls). Matrix metalloproteinase 7 (MMP7) and MMP1—the two plasma proteins whose levels were most increased in patients with IPF compared to controls—were key components of this signature. Concentrations of MMP7 and MMP1 were higher in bronchoalveolar lavage samples (fluid obtained by washing out the lungs with saline) and in lung tissue samples from patients with IPF than in similar samples taken from healthy individuals. Plasma concentrations of MMP7 and MMP1 were significantly higher in patients with IPF than in patients with hypersensitivity pneumonitis, an interstitial lung disease that mimics IPF, but not increased in patients with chronic obstructive pulmonary disease or sarcoidosis, two other lung diseases. In an independent validation group, patients with IPF and familial pulmonary fibrosis had increased plasma concentrations of MMP7 and MMP1 that correlated with the severity of their disease. In addition, MMP7 concentrations were raised in close relatives of people with familial pulmonary fibrosis who had normal lung function tests but some lung scarring.
What Do These Findings Mean?
These findings provide evidence for a protein signature in the blood for IPF and suggest MMP1 and MMP7 may be useful as biomarkers for IPF. These two matrix metalloproteinases have previously been suggested to be involved in the development of IPF. However, additional work is probably needed to confirm that increased plasma concentrations MMP7 and MMP1 are specific for IPF, since it may be that these markers will not distinguish IPF from other interstitial lung diseases.
Additional Information.
Please access these Web sites via the online version of this summary at
Read a related PLoS Medicine Perspective article
The MedlinePlus Encyclopedia has a page on idiopathic pulmonary fibrosis (in English and Spanish) and on pulmonary fibrosis
The US National Heart Lung and Blood Institute and the British Lung Foundation also provide information on IPF for patients and relatives
Some of the researchers involved in this study provide more details about what might go wrong in IPF in a recent PLoS Medicine article
PMCID: PMC2346504  PMID: 18447576
4.  Voice Disorder in Cystic Fibrosis Patients 
PLoS ONE  2014;9(5):e96769.
Cystic fibrosis is a common autosomal recessive disorder with drastic respiratory symptoms, including shortness of breath and chronic cough. While most of cystic fibrosis treatment is dedicated to mitigating the effects of respiratory dysfunction, the potential effects of this disease on vocal parameters have not been systematically studied. We hypothesized that cystic fibrosis patients, given their characteristic respiratory disorders, would also present dysphonic symptoms. Given that voice disorders can severely impair quality of life, the identification of a potential cystic fibrosis-related dysphonia could be of great value for the clinical evaluation and treatment of this disease. We tested our hypothesis by measuring vocal parameters, using both objective physical measures and the GRBAS subjective evaluation method, in male and female cystic fibrosis patients undergoing conventional treatment and compared them to age and sex matched controls. We found that cystic fibrosis patients had a significantly lower vocal intensity and harmonic to noise ratio, as well as increased levels of jitter and shimmer. In addition, cystic fibrosis patients also showed higher scores of roughness, breathiness and asthenia, as well as a significantly altered general grade of dysphonia. When we segregated the results according to sex, we observed that, as a group, only female cystic fibrosis patients had significantly lower values of harmonic to noise ratio and an abnormal general grade of dysphonia in relation to matched controls, suggesting that cystic fibrosis exerts a more pronounced effect on vocal parameters of women in relation to men. Overall, the dysphonic characteristics of CF patients can be explained by dysfunctions in vocal fold movement and partial upper airway obstruction, potentially caused by the accumulation of mucus and chronic cough characteristic of CF symptomatology. Our results show that CF patients exhibit significant dysphonia and suggest they may potentially benefit from voice therapy as a parallel treatment strategy.
PMCID: PMC4010511  PMID: 24796691
5.  Biventricular Pacing (Cardiac Resynchronization Therapy) 
Executive Summary
In 2002, (before the establishment of the Ontario Health Technology Advisory Committee), the Medical Advisory Secretariat conducted a health technology policy assessment on biventricular (BiV) pacing, also called cardiac resynchronization therapy (CRT). The goal of treatment with BiV pacing is to improve cardiac output for people in heart failure (HF) with conduction defect on ECG (wide QRS interval) by synchronizing ventricular contraction. The Medical Advisory Secretariat concluded that there was evidence of short (6 months) and longer-term (12 months) effectiveness in terms of cardiac function and quality of life (QoL). More recently, a hospital submitted an application to the Ontario Health Technology Advisory Committee to review CRT, and the Medical Advisory Secretariat subsequently updated its health technology assessment.
Chronic HF results from any structural or functional cardiac disorder that impairs the ability of the heart to act as a pump. It is estimated that 1% to 5% of the general population (all ages) in Europe have chronic HF. (1;2) About one-half of the patients with HF are women, and about 40% of men and 60% of women with this condition are aged older than 75 years.
The incidence (i.e., the number of new cases in a specified period) of chronic HF is age dependent: from 1 to 5 per 1,000 people each year in the total population, to as high as 30 to 40 per 1,000 people each year in those aged 75 years and older. Hence, in an aging society, the prevalence (i.e., the number of people with a given disease or condition at any time) of HF is increasing, despite a reduction in cardiovascular mortality.
A recent study revealed 28,702 patients were hospitalized for first-time HF in Ontario between April 1994 and March 1997. (3) Women comprised 51% of the cohort. Eighty-five percent were aged 65 years or older, and 58% were aged 75 years or older.
Patients with chronic HF experience shortness of breath, a limited capacity for exercise, high rates of hospitalization and rehospitalization, and die prematurely. (2;4) The New York Heart Association (NYHA) has provided a commonly used functional classification for the severity of HF (2;5):
Class I: No limitation of physical activity. No symptoms with ordinary exertion.
Class II: Slight limitations of physical activity. Ordinary activity causes symptoms.
Class III: Marked limitation of physical activity. Less than ordinary activity causes symptoms. Asymptomatic at rest.
Class IV: Inability to carry out any physical activity without discomfort. Symptoms at rest.
The National Heart, Lung, and Blood Institute estimates that 35% of patients with HF are in functional NYHA class I; 35% are in class II; 25%, class III; and 5%, class IV. (5) Surveys (2) suggest that from 5% to 15% of patients with HF have persistent severe symptoms, and that the remainder of patients with HF is evenly divided between those with mild and moderately severe symptoms.
Overall, patients with chronic, stable HF have an annual mortality rate of about 10%. (2) One-third of patients with new-onset HF will die within 6 months of diagnosis. These patients do not survive to enter the pool of those with “chronic” HF. About 60% of patients with incident HF will die within 3 years, and there is limited evidence that the overall prognosis has improved in the last 15 years.
To date, the diagnosis and management of chronic HF has concentrated on patients with the clinical syndrome of HF accompanied by severe left ventricular systolic dysfunction. Major changes in treatment have resulted from a better understanding of the pathophysiology of HF and the results of large clinical trials. Treatment for chronic HF includes lifestyle management, drugs, cardiac surgery, or implantable pacemakers and defibrillators. Despite pharmacologic advances, which include diuretics, angiotensin-converting enzyme inhibitors, beta-blockers, spironolactone, and digoxin, many patients remain symptomatic on maximally tolerated doses.
The Technology
Owing to the limitations of drug therapy, cardiac transplantation and device therapies have been used to try to improve QoL and survival of patients with chronic HF. Ventricular pacing is an emerging treatment option for patients with severe HF that does not respond well to medical therapy. Traditionally, indications for pacing include bradyarrhythmia, sick sinus syndrome, atrioventricular block, and other indications, including combined sick sinus syndrome with atrioventricular block and neurocardiogenic syncope. Recently, BiV pacing as a new, adjuvant therapy for patients with chronic HF and mechanical dyssynchrony has been investigated. Ventricular dysfunction is a sign of HF; and, if associated with severe intraventricular conduction delay, it can cause dyssynchronous ventricular contractions resulting in decreased ventricular filling. The therapeutic intent is to activate both ventricles simultaneously, thereby improving the mechanical efficiency of the ventricles.
About 30% of patients with chronic HF have intraventricular conduction defects. (6) These conduction abnormalities progress over time and lead to discoordinated contraction of an already hemodynamically compromised ventricle. Intraventricular conduction delay has been associated with clinical instability and an increased risk of death in patients with HF. (7) Hence, BiV pacing, which involves pacing left and right ventricles simultaneously, may provide a more coordinated pattern of ventricular contraction and thereby potentially reduce QRS duration, and intraventricular and interventricular asynchrony. People with advanced chronic HF, a wide QRS complex (i.e., the portion of the electrocardiogram comprising the Q, R, and S waves, together representing ventricular depolarization), low left ventricular ejection fraction and contraction dyssynchrony in a viable myocardium and normal sinus rhythm, are the target patients group for BiV pacing. One-half of all deaths in HF patients are sudden, and the mode of death is arrhythmic in most cases. Internal cardioverter defibrillators (ICDs) combined with BiV pacemakers are therefore being increasingly considered for patients with HF who are at high risk of sudden death.
Current Implantation Technique for Cardiac Resynchronization
Conventional dual-chamber pacemakers have only 2 leads: 1 placed in the right atrium and the other in the right ventricle. The technique used for BiV pacemaker implantation also uses right atrial and ventricular pacing leads, in addition to a left ventricle lead advanced through the coronary sinus into a vein that runs along the ventricular free wall. This permits simultaneous pacing of both ventricles to allow resynchronization of the left ventricle septum and free wall.
Mode of Operation
Permanent pacing systems consist of an implantable pulse generator that contains a battery and electronic circuitry, together with 1 (single-chamber pacemaker) or 2 (dual-chamber pacemaker) leads. Leads conduct intrinsic atrial or ventricular signals to the sensing circuitry and deliver the pulse generator charge to the myocardium (muscle of the heart).
Complications of Biventricular Pacemaker Implantation
The complications that may arise when a BiV pacemaker is implanted are similar to those that occur with standard pacemaker implantation, including pneumothorax, perforation of the great vessels or the myocardium, air embolus, infection, bleeding, and arrhythmias. Moreover, left ventricular pacing through the coronary sinus can be associated with rupture of the sinus as another complication.
Conclusion of 2003 Review of Biventricular Pacemakers by the Medical Advisory Secretariat
The randomized controlled trials (RCTs) the Medical Advisory Secretariat retrieved analyzed chronic HF patients that were assessed for up to 6 months. Other studies have been prospective, but nonrandomized, not double-blinded, uncontrolled and/or have had a limited or uncalculated sample size. Short-term studies have focused on acute hemodynamic analyses. The authors of the RCTs reported improved cardiac function and QoL up to 6 months after BiV pacemaker implantation; therefore, there is level 1 evidence that patients in ventricular dyssynchrony who remain symptomatic after medication might benefit from this technology. Based on evidence made available to the Medical Advisory Secretariat by a manufacturer, (8) it appears that these 6-month improvements are maintained at 12-month follow-up.
To date, however, there is insufficient evidence to support the routine use of combined ICD/BiV devices in patients with chronic HF with prolonged QRS intervals.
Summary of Updated Findings Since the 2003 Review
Since the Medical Advisory Secretariat’s review in 2003 of biventricular pacemakers, 2 large RCTs have been published: COMPANION (9) and CARE-HF. (10) The characteristics of each trial are shown in Table 1. The COMPANION trial had a number of major methodological limitations compared with the CARE-HF trial.
Characteristics of the COMPANION and CARE-HF Trials*
BiV indicates biventricular; ICD, implantable cardioverter defibrillator; EF, ejection fraction; QRS, the interval representing the Q, R and S waves on an electrocardiogram; FDA, United States Food and Drug Administration.
Overall, CARE-HF showed that BiV pacing significantly improves mortality, QoL, and NYHA class in patients with severe HF and a wide QRS interval (Tables 2 and 3).
CARE-HF Results: Primary and Secondary Endpoints*
BiV indicates biventricular; NNT, number needed to treat.
Cleland JGF, Daubert J, Erdmann E, Freemantle N, Gras D, Kappenberger L et al. The effect of cardiac resynchronization on morbidity and mortality in heart failure (CARE-HF). New England Journal of Medicine 2005; 352:1539-1549; Copyright 2003 Massachusettes Medical Society. All rights reserved. (10)
CARE H-F Results: NYHA Class and Quality of Life Scores*
Minnesota Living with Heart Failure scores range from 0 to 105; higher scores reflect poorer QoL.
European Quality of Life–5 Dimensions scores range from -0.594 to 1.000; 1.000 indicates fully healthy; 0, dead
Cleland JGF, Daubert J, Erdmann E, Freemantle N, Gras D, Kappenberger L et al. The effect of cardiac resynchronization on morbidity and mortality in heart failure (CARE-HF). New England Journal of Medicine 2005; 352:1539-1549; Copyright 2005 Massachusettes Medical Society. All rights reserved.(10)
GRADE Quality of Evidence
The quality of these 3 trials was examined according to the GRADE Working Group criteria, (12) (Table 4).
Quality refers to criteria such as the adequacy of allocation concealment, blinding, and follow-up.
Consistency refers to the similarity of estimates of effect across studies. If there is an important unexplained inconsistency in the results, confidence in the estimate of effect for that outcome decreases. Differences in the direction of effect, the size of the differences in effect, and the significance of the differences guide the decision about whether important inconsistency exists.
Directness refers to the extent to which the people interventions and outcome measures are similar to those of interest. For example, there may be uncertainty about the directness of the evidence if the people of interest are older, sicker, or have more comorbid conditions than do the people in the studies.
As stated by the GRADE Working Group, (12) the following definitions were used in grading the quality of the evidence:
High: Further research is very unlikely to change our confidence on the estimate of effect.
Moderate: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low: Any estimate of effect is very uncertain.
Quality of Evidence: CARE-HF and COMPANION
Overall, there is evidence that BiV pacemakers are effective for improving mortality, QoL, and functional status in patients with NYHA class III/IV HF, an EF less than 0.35, a QRS interval greater than 120 ms, who are refractory to drug therapy.
As per the GRADE Working Group, recommendations considered the following 4 main factors:
The tradeoffs, taking into account the estimated size of the effect for the main outcome, the confidence limits around those estimates, and the relative value placed on the outcome
The quality of the evidence (Table 4)
Translation of the evidence into practice in a specific setting, taking into consideration important factors that could be expected to modify the size of the expected effects such as proximity to a hospital or availability of necessary expertise
Uncertainty about the baseline risk for the population of interest
The GRADE Working Group also recommends that incremental costs of health care alternatives should be considered explicitly alongside the expected health benefits and harms. Recommendations rely on judgments about the value of the incremental health benefits in relation to the incremental costs. The last column in Table 5 shows the overall trade-off between benefits and harms and incorporates any risk/uncertainty.
For BiV pacing, the overall GRADE and strength of the recommendation is moderate: the quality of the evidence is moderate/high (because of some uncertainty due to methodological limitations in the study design, e.g., no blinding), but there is also some risk/uncertainty in terms of the estimated prevalence and wide cost-effectiveness estimates (Table 5).
For the combination BiV pacing/ICD, the overall GRADE and strength of the recommendation is weak—the quality of the evidence is low (because of uncertainty due to methodological limitations in the study design), but there is also some risk/uncertainty in terms of the estimated prevalence, high cost, and high budget impact (Table 5). There are indirect, low-quality comparisons of the effectiveness of BiV pacemakers compared with the combination BiV/ICD devices.
A stronger recommendation can be made for BiV pacing only compared with the combination BiV/ICD device for patients with an EF less than or equal to 0.35, and a QRS interval over or equal to 120 ms, and NYHA III/IV symptoms, and refractory to optimal medical therapy (Table 5).
There is moderate/high-quality evidence that BiV pacemakers significantly improve mortality, QoL, and functional status.
There is low-quality evidence that combined BiV/ICD devices significantly improve mortality, QoL, and functional status.
To date, there are no direct comparisons of the effectiveness of BiV pacemakers compared with the combined BiV/ICD devices in terms of mortality, QoL, and functional status.
Overall GRADE and Strength of Recommendation
BiV refers to biventricular; ICD, implantable cardioverter defibrillator; NNT, number needed to treat.
PMCID: PMC3382419  PMID: 23074464
6.  Future Directions in Early Cystic Fibrosis Lung Disease Research 
Since the 1989 discovery that mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF), there has been substantial progress toward understanding the molecular basis for CF lung disease, leading to the discovery and development of new therapeutic approaches. However, the earliest impact of the loss of CFTR function on airway physiology and structure and its relationship to initial infection and inflammation are poorly understood. Universal newborn screening for CF in the United States represents an unprecedented opportunity for investigating CF clinical manifestations very early in life. Recently developed animal models with pulmonary phenotypic manifestations also provide a window into the early consequences of this genetic disorder. For these reasons, the National Heart, Lung, and Blood Institute (NHLBI) convened a working group of extramural experts, entitled “Future Research Directions in Early CF Lung Disease” on September 21–22, 2010, to identify future research directions of great promise in CF. The priority areas identified included (1) exploring pathogenic mechanisms of early CF lung disease; (2) leveraging newborn screening to elucidate the natural history of early lung disease; (3) developing a spectrum of biomarkers of early lung disease that reflects CF pathophysiology, clinical outcome, and response to treatment; (4) exploring the role of genetics/genomics (e.g., modifier genes, gene–environmental interactions, and epigenetics) in early CF pathogenesis; (5) defining early microbiological events in CF lung disease; and (6) elucidating the initial airway inflammatory, remodeling, and repair mechanisms in CF lung disease.
PMCID: PMC3360572  PMID: 22312017
cystic fibrosis; airway disease; innate immunity; microbiology; genetics
7.  New animal models of cystic fibrosis: what are they teaching us? 
Purpose of review
Cystic fibrosis is the first human genetic disease to benefit from the directed engineering of three different species of animal models (mice, pigs, and ferrets). Recent studies on the cystic fibrosis pig and ferret models are providing new information about the pathophysiology of cystic fibrosis in various organ systems. Additionally, new conditional cystic fibrosis transmembrane conductance regulator (CFTR) knockout mice are teaching unexpected lessons about CFTR function in surprising cellular locations. Comparisons between these animal models and the human condition are key to dissecting the complexities of disease pathophysiology in cystic fibrosis.
Recent findings
Cystic fibrosis pigs and ferrets have provided new models to study the spontaneous development of disease in the lung and pancreas, two organs that are largely spared overt spontaneous disease in cystic fibrosis mice. New cystic fibrosis mouse models are now interrogating CFTR functions involved in growth and inflammation at an organ-based level using conditional knockout technology. Together, these models are providing new insights on the human condition.
Basic and clinical cystic fibrosis research will benefit greatly from the comparative pathophysiology of cystic fibrosis mice, pigs, and ferrets. Both similarities and differences between these three cystic fibrosis models will inform pathophysiologically important mechanisms of CFTR function in humans and aid in the development of both organ-specific and general therapies for cystic fibrosis.
PMCID: PMC3596000  PMID: 21857224
cystic fibrosis; ferret; mouse; pathology; pathophysiology; pig
8.  Counteracting suppression of CFTR and voltage-gated K+ channels by a bacterial pathogenic factor with the natural product tannic acid 
eLife  2014;3:e03683.
Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) cause recurring bacterial infection in CF patients' lungs. However, the severity of CF lung disease correlates poorly with genotype. Antibiotic treatment helps dramatically prolong patients' life. The lung disease generally determines prognosis and causes most morbidity and mortality; early control of infections is thus critical. Staphylococcus aureus is a main cause of early infection in CF lungs. It secretes sphingomyelinase (SMase) C that can suppress CFTR activity. SMase C also inhibits voltage-gated K+ channels in lymphocytes; inhibition of these channels causes immunosuppression. SMase C's pathogenicity is further illustrated by the demonstration that once Bacillus anthracis is engineered to express high levels of SMase C, the resulting mutant can evade the host immunity elicited by a live vaccine because additional pathogenic mechanisms are created. By screening a chemical library, we find that the natural product tannic acid is an SMase C antidote.
eLife digest
Cystic fibrosis is an inherited disease that mainly affects the lungs and the intestine. It is caused by defective copies of a protein called CFTR, which normally allows chloride ions to flow in and out of cells through the cell membrane. The activity of the CFTR protein is important for transferring fluid in and out of cells, and the dysfunctional CTFR protein causes the cells lining the lungs and the intestine to produce thick mucus. This leads to problems with breathing and absorbing nutrients, and makes the lungs of people with cystic fibrosis more susceptible to infections.
Recurring lung infections aggravate the symptoms of cystic fibrosis and worsen the predicted outcome for sufferers. A common skin bacterium, called Staphylococcus aureus, is one of the first to colonize the lungs of young cystic fibrosis patients. This pathogen releases an enzyme that can further reduce any residual activity of the defective CTFR protein. The enzyme—called sphingomyelinase C (or SMase C for short)—also interferes with the function of another protein that allows potassium ions to flow out of immune cells. This effect in turn reduces the body's ability to fight the infection.
Now Ramu et al. have found, by using cells grown in a laboratory, that the enzyme released by the bacteria would remain active long after the bacteria had been killed. This finding suggests that a combination therapy of antibiotics that kill the bacteria and a drug that inhibits the enzyme function may greatly improve treatments for cystic fibrosis.
Ramu et al. then tested a collection of over 2000 edible naturally-occurring chemicals and drugs, which are already approved for use in humans, to see if any could counteract the activity of the enzyme. A single natural chemical called tannic acid was shown to prevent both the negative effects on CTFR and those on the potassium channel protein.
Other pathogenic bacteria also produce an SMase C enzyme and Ramu et al. showed that tannic acid can also interfere with the anthrax bacterium's enzyme. This suggests that treatment with tannic acid may improve the outcome in a number of bacterial infections. Further experimental work is now needed to establish whether tannic acid can alleviate the symptoms of infectious disease in animal models.
PMCID: PMC4192643  PMID: 25313718
potassium channels; CFTR; phospholipase; sphingomyelinase; toxin; channel inhibition; Xenopus
9.  Hospital care for adults with cystic fibrosis: an overview and comparison between special cystic fibrosis clinics and general clinics using a patient questionnaire. 
Thorax  1994;49(4):300-306.
BACKGROUND--Provision of medical care for adult patients with cystic fibrosis is an increasing problem as the number of patients surviving into adulthood increases. Recent reports have suggested that care is best provided in specialist centres because of longer survival. Recent changes in the National Health Service funding and delivery of service may adversely affect the provision of such a specialist service. The aim of this study was to assess the current pattern of medical service received by adults with cystic fibrosis and to compare the type of care between special cystic fibrosis and general clinics. METHODS--Confidential postal questionnaires were sent to all 1052 members of the Association of Cystic Fibrosis Adults (ACFA) comprising 59% of the UK population of cystic fibrosis patients over 15 years and 80% over 25 years of age. The response rate was 82%. RESULTS--Two thirds of patients were attending special cystic fibrosis clinics for either adults or adults and children. There were significant differences in the proportion of patients using special cystic fibrosis clinics between regions but not between social class groups. Significant differences between cystic fibrosis and general clinics were noted. Patients attending cystic fibrosis clinics were more likely to have had simple clinical investigations (blood tests, sputum culture, oxygen saturation, chest radiography, weight and lung function measurement) in the previous year. They were also more likely to have received intravenous antibiotics at home, and to have access to paramedical personnel. Patients attending cystic fibrosis clinics were taking higher doses of pancreatic enzyme supplements with respect to quantity and potency of preparation. Such patients also had less severe symptoms irrespective of social class, and were more likely to be satisfied with professional aspects of their care. Regardless of type of clinic, potential deficiencies were identified in overall medical care with omission of clinical investigations in severely affected patients and evidence of undertreated respiratory and digestive symptoms in patients with moderate and severe disease. CONCLUSIONS--This survey provides evidence that adults with cystic fibrosis attending special cystic fibrosis clinics receive more intensive care, have better symptom control, and are more satisfied with the service provided than those attending general clinics.
PMCID: PMC475360  PMID: 8202897
10.  Medical therapy of stricturing Crohn’s disease: what the gut can learn from other organs - a systematic review 
Crohn’s disease (CD) is a chronic remitting and relapsing disease. Fibrostenosing complications such as intestinal strictures, stenosis and ultimately obstruction are some of its most common long-term complications. Despite recent advances in the pathophysiological understanding of CD and a significant improvement of anti-inflammatory therapeutics, medical therapy for stricturing CD is still inadequate. No specific anti-fibrotic therapy exists and the incidence rate of strictures has essentially remained unchanged. Therefore, the current therapy of established fibrotic strictures comprises mainly endoscopic dilation as well as surgical approaches. However, these treatment options are associated with major complications as well as high recurrence rates. Thus, a specific anti-fibrotic therapy for CD is urgently needed. Importantly, there is now a growing body of evidence for prevention as well as effective medical treatment of fibrotic diseases of other organs such as the skin, lung, kidney and liver. In face of the similarity of molecular mechanisms of fibrogenesis across these organs, translation of therapeutic approaches from other fibrotic diseases to the intestine appears to be a promising treatment strategy. In particular transforming growth factor beta (TGF-β) neutralization, selective tyrosine kinase inhibitors, blockade of components of the renin-angiotensin system, IL-13 inhibitors and mammalian target of rapamycin (mTOR) inhibitors have emerged as potential drug candidates for anti-fibrotic therapy and may retard progression or even reverse established intestinal fibrosis. However, major challenges have to be overcome in the translation of novel anti-fibrotics into intestinal fibrosis therapy, such as the development of appropriate biomarkers that predict the development and accurately monitor therapeutic responses. Future clinical studies are a prerequisite to evaluate the optimal timing for anti-fibrotic treatment approaches, to elucidate the best routes of application, and to evaluate the potential of drug candidates to reach the ultimate goal: the prevention or reversal of established fibrosis and strictures in CD patients.
PMCID: PMC4230721  PMID: 24678903
Crohn’s disease; Intestinal fibrosis; Organ fibrosis; Anti-fibrotic agents
11.  New agents for the treatment of hepatitis C in patients co-infected with HIV 
Pilot trials evaluating the efficacy and safety of the first licensed hepatitis C virus (HCV) protease inhibitors (PIs), boceprevir (BOC) and telaprevir (TVR), for the treatment of genotype 1 infection in HCV/HIV co-infected patients revealed similar results as in HCV mono-infected patients. HCV liver disease progresses more rapidly in co-infected patients, particularly with advanced immunodeficiency. Therefore, HCV treatment in HIV is of great importance. However, dual therapy with pegylated interferon (PegIFN) and ribavirin (RBV) has been associated with lower cure rates and increased toxicities in co-infected subjects, thereby limiting overall HCV therapy uptake. The availability of HCV PIs opens new perspectives for HCV cure in co-infected patients, with a 70% sustained virologic response (SVR) rate in HCV treatment-naïve patients. Despite these impressive advances, the use of the new treatment options has been low, reflecting the complex issues with modern triple HCV therapy. Indeed pill burden, adverse events (AEs), drug–drug interactions (DDIs) and high costs complicate HCV therapy in HIV. So far, studies have shown no tolerability differences in mono- and co-infected patients with the early stages of liver fibrosis. Regarding DDIs between HVC PIs and antiretroviral drugs, TVR can be safely administered with efavirenz (with dose adjustment of TVR), etravirine (ETR), rilpivirine, boosted atazanavir (ATV/r) and raltegravir (RAL), while BOC can be safely administered with ETR, RAL and potentially ATV/r for treatment-naïve patients under careful monitoring. Currently, the great number of HCV molecules under development is promising substantially improved treatment paradigms with shorter treatment durations, fewer AEs, less DDIs, once-daily administration and even interferon-free regimens. The decision to treat now with the available HCV PIs or defer therapy until the second generation of HCV direct acting antivirals become available should be based on liver fibrosis staging and fibrosis progression during follow up. More data are urgently needed regarding the efficacy of triple therapy in HIV/HCV co-infected patients who previously failed PegIFN/RBV therapy as well as in patients with more advanced fibrosis stages.
PMCID: PMC4040720  PMID: 25165545
HIV; hepatitis C; DAA; pegylated interferon; ribavirin
12.  Bronchiectasis 
BMJ Clinical Evidence  2008;2008:1507.
Bronchiectasis is usually a complication of previous lower respiratory infection, and causes chronic cough and copious production of sputum, which is often purulent. Bronchiectasis may cause signs of chronic obstructive pulmonary disease. It can also be associated with cystic fibrosis and other congenital disorders, foreign body inhalation, and other causes of lung damage.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments in people with bronchiectasis but without cystic fibrosis? We searched: Medline, Embase, The Cochrane Library and other important databases up to July 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We performed a GRADE evaluation of the quality of evidence for interventions.
We found 16 systematic reviews, RCTs, or observational studies that met our inclusion criteria.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: anticholinergic therapy, bronchopulmonary hygiene physical therapy, exercise or physical training, hyperosmolar agents (inhaled), leukotriene receptor antagonists, methyl-xanthines (oral), mucolytics (bromhexine or deoxyribonuclease), prolonged-use antibiotics, beta2 agonists, steroids (inhaled, oral), and surgery.
Key Points
Bronchiectasis is characterised by irreversible widening of medium-sized airways, with inflammation, chronic bacterial infection, and destruction of bronchial walls. Bronchiectasis is usually a complication of previous lower respiratory infection, and causes chronic cough and production of copious sputum, which is often purulent. Bronchiectasis may cause signs of COPD. It can also be associated with cystic fibrosis and other congenital disorders, foreign-body inhalation, and other causes of lung damage.
Exercise or inspiratory muscle training may improve quality of life and exercise endurance in people with bronchiectasis but without cystic fibrosis.
We do not know whether bronchopulmonary hygiene physical therapy, mucolytics, inhaled hyperosmolar agents, inhaled corticosteroids, oral corticosteroids, leukotriene receptor antagonists,short-acting beta2 agonists , long-acting beta2 agonists, anticholinergic therapy, or surgery are beneficial, because few studies have been found. Inhaled corticosteroids may reduce sputum volume compared with placebo, but have not been shown to reduce exacerbations. Oral methyl-xanthines and surgery are often used in bronchiectasis, but we found no good-quality studies of either treatment.Surgery is often considered for people with extreme damage to one or two lobes of the lung who are at risk of severe infection or bleeding. Prolonged-use antibiotics improve clinical response rates (according to treating physicians at follow-up), but may not reduce exacerbation rates or lung function compared with placebo.
PMCID: PMC2907995  PMID: 19450337
13.  Early acute pancreatitis in a child with compound heterozygosis ∆F508/R1438W/Y1032C cystic fibrosis: a case report 
Recent studies suggest an important role of the cystic fibrosis transmembrane conductance regulator gene in the development of pancreatitis. It occurs approximately in 20% of patients with cystic fibrosis and almost exclusively in pancreatic sufficient people. Newborn screening and improved panels of deoxyribonucleic acid mutation analysis techniques are revealing more rare and nonclassical pictures of the disease, generally associated with pancreatic sufficiency and with an increased risk of developing pancreatitis. Mutations R1438 and Y1032 are considered rare mutations, and, when singularly associated with ∆F508, lead to a mild phenotype with pancreatic sufficiency and no detectable respiratory involvement.
Case presentation
We present the case of a Caucasian girl, aged six years, whose genotype was characterized by three different mutations ∆F508, R1438W and Y1032C, never reported, together, in the same patient. She presented with a positive immunoreactive trypsinogen screening, a borderline sweat test, and, in the first years, a favorable pulmonary course, and pancreatic sufficiency. At the age of six years, she presented with a sudden episode of acute abdominal pain, anorexia and fever. A diagnosis of pancreatitis was made after clinical and laboratory examinations. Venous rehydration, bowel rest and therapy with ursodeoxycholic acid resulted in complete remission.
The treatment was successful, with normalization of her symptoms and laboratory parameters within four weeks.
There has been a vast expansion in the understanding of the wide range of phenotypes associated with cystic fibrosis transmembrane conductance regulator dysfunction since the discovery of the cystic fibrosis transmembrane conductance regulator gene. The genotype-phenotype correlation in pancreatitis is rare compared to other organ manifestations, since this is seen almost exclusively among pancreatic sufficient patients with cystic fibrosis. Our study supports that compound heterozygosis ∆F508-R1438W/Y1032C is a 'cystic fibrosis-causing genotype' characterized by an immunoreactive trypsinogen positive screening, abnormal sweat chloride testing, and pancreatic sufficiency, with an increased risk of acute pancreatitis at an early age.
PMCID: PMC3750286  PMID: 23883480
Pancreatitis; Cystic fibrosis; CFTR; ∆F508-R1438W and Y1032C; Mild phenotype
14.  Bronchiectasis 
Clinical Evidence  2011;2011:1507.
Bronchiectasis is usually a complication of previous lower respiratory infection, and causes chronic cough and copious production of sputum, which is often purulent. Bronchiectasis may cause signs of chronic obstructive pulmonary disease. It can also be associated with cystic fibrosis and other congenital disorders, foreign body inhalation, and other causes of lung damage.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments in people with bronchiectasis but without cystic fibrosis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We performed a GRADE evaluation of the quality of evidence for interventions.
We found 19 systematic reviews, RCTs, or observational studies that met our inclusion criteria.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: anticholinergic therapy, beta2 agonists, bronchopulmonary hygiene physical therapy, corticosteroids (inhaled, oral), exercise or physical training, hyperosmolar agents (inhaled), leukotriene receptor antagonists, methyl-xanthines (oral), mucolytics (bromhexine or deoxyribonuclease), prolonged-use antibiotics, and surgery.
Key Points
Bronchiectasis is characterised by irreversible widening of medium-sized airways, with inflammation, chronic bacterial infection, and destruction of bronchial walls. Bronchiectasis is usually a complication of previous lower respiratory infection, and causes chronic cough and production of copious sputum, which is often purulent. Bronchiectasis may cause signs of COPD. It can also be associated with cystic fibrosis and other congenital disorders, foreign-body inhalation, and other causes of lung damage.
Exercise or inspiratory muscle training may improve quality of life and exercise endurance in people with bronchiectasis but without cystic fibrosis.
Prolonged-use antibiotics improve clinical response rates (according to treating physicians at follow-up; Leicester Cough Questionnaire score), and may improve quality of life and reduce time to first exacerbation, but they may not reduce exacerbation rates or improve lung function.
We don't know whether bronchopulmonary hygiene physical therapy, mucolytics, inhaled hyperosmolar agents, oral corticosteroids, leukotriene receptor antagonists, short-acting beta2 agonists, long-acting beta2 agonists, or anticholinergic therapy are beneficial, as we found few studies.
Inhaled corticosteroids may reduce sputum volume and improve dyspnoea, but have not been shown to reduce exacerbations.
Oral methyl-xanthines and surgery are often used in bronchiectasis, but we found no good-quality trials of either treatment. Surgery is often considered for people with extreme damage to one or two lobes of the lung who are at risk of severe infection or bleeding.
PMCID: PMC3275315  PMID: 21846412
15.  Measuring Airway Surface Liquid Depth in Ex Vivo Mouse Airways by X-Ray Imaging for the Assessment of Cystic Fibrosis Airway Therapies 
PLoS ONE  2013;8(1):e55822.
In the airways of those with cystic fibrosis (CF), the leading pathophysiological hypothesis is that an ion channel defect results in a relative decrease in airway surface liquid (ASL) volume, producing thick and sticky mucus that facilitates the establishment and progression of early fatal lung disease. This hypothesis predicts that any successful CF airway treatment for this fundamental channel defect should increase the ASL volume, but up until now there has been no method of measuring this volume that would be compatible with in vivo monitoring. In order to accurately monitor the volume of the ASL, we have developed a new x-ray phase contrast imaging method that utilizes a highly attenuating reference grid. In this study we used this imaging method to examine the effect of a current clinical CF treatment, aerosolized hypertonic saline, on ASL depth in ex vivo normal mouse tracheas, as the first step towards non-invasive in vivo ASL imaging. The ex vivo tracheas were treated with hypertonic saline, isotonic saline or no treatment using a nebuliser integrated within a small animal ventilator circuit. Those tracheas exposed to hypertonic saline showed a transient increase in the ASL depth, which continued for nine minutes post-treatment, before returning to baseline by twelve minutes. These findings are consistent with existing measurements on epithelial cell cultures, and therefore suggest promise for the future development of in vivo testing of treatments. Our grid-based imaging technique measures the ASL depth with micron resolution, and can directly observe the effect of treatments expected to increase ASL depth, prior to any changes in overall lung health. The ability to non-invasively observe micron changes in the airway surface, particularly if achieved in an in vivo setting, may have potential in pre-clinical research designed to bring new treatments for CF and other airway diseases to clinical trials.
PMCID: PMC3559635  PMID: 23383288
16.  Analysis of Effect of Antiviral Therapy on Regression of Liver Fibrosis in Patient with HCV Infection 
Materia Socio-Medica  2014;26(3):172-176.
HCV infection is characterized by a tendency towards chronicity. Acute HCV infection progresses to chronic infection in 70% of cases. Hepatitis C virus infection can cause progressive liver injury and lead to fibrosis and eventually cirrhosis. The degree of histologic fibrosis is an important marker of the stage of the disease. One of current standard treatment for CHC infection is the combination of PEG-IFN α and ribavirin.
The aim of the study was to investigate the effect of the therapy with Peginterferon alfa-2a or alfa-2b plus Ribavirin on evolution of liver fibrosis in patients with chronic hepatitis C. Also, our aim was to examine whether there was a difference between the genders in the efficacy of these antiviral therapy. Our goal also was to determine effect of the therapy with Peginterferon alfa-2a or alfa-2b plus Ribavirin on evolution of liver steatosis in patients with chronic hepatitis C.
Patients and Methods:
A retrospective study was made of chronic hepatitis C patients who had been treated from 2005 to April 2014 at the Clinic of Gastroenterohepatology, Clinical Center University of Sarajevo. We reviewed 40 patient medical records to collect demographic, epidemiological and clinical information, as information on liver biopsies that was performed prior to the antiviral therapy and FibroScan® test that was performed after the antiviral therapy. For the processing of data SPSS (Statistical Package for the Social Sciences Program) for Windows, ver. 21.0 statistical software was used. Comparisons between qualitative and quantitative variables were performed using the Student t-test. Mann Whitney U test was used to compare differences in variables such as fibrosis stage and steatosis grade. A value of p<0.05 was considered as statistically significant.
After treatment, there was a statistically significant increase in the number of patients with no fibrosis (p<0.05). There was no statistically significant reduction in the number of patients with cirrhosis (F4) (p>0.05). There was significantly higher decrease of fibrosis progression at the patients that were in an mild-to-moderate fibrosis (F1/F2/F3), patients that were in advanced stage of fibrosis (F4) at the time of the pre-treatment did not have a statistically significant fibrosis reduction. We found significant association in evolution of fibrosis after treatment with PEG-IFN α2a (40) kD and PEG-IFNα2a (12,5) kD with ribavirin (p< 0.05). We also found significant association in evolution of steatosis after treatment with PEG-IFN α2a (40) kD and PEG-IFNα2a (12,5) kD with ribavirin (p < 0.05). There was statistically significant differences (p<0.05) between genders within fibrosis qualitative evolution.
There were significant regression of fibrosis especially at the patients that were in an mild-to-moderate fibrosis (F1/F2/F3), patients that were in advanced stage of fibrosis (F4) at the time of the pre-treatment did not have a statistically significant fibrosis reduction after treatment with PEG-IFN α2a (40) kD and PEG-IFNα2b (12,5) kD with ribavirin. Our results showed significant improvement in steatosis in patients infected with HCV after treatment with PEG-IFN α2a (40) kD and PEG-IFNα2b (12,5) kD with ribavirin. Those results provides further evidence for direct involvement of HCV and antiviral therapy in the pathogenesis of hepatic steatosis. Female gender showed a higher degree of fibrosis reduction.
PMCID: PMC4130668  PMID: 25126010
Antiviral Therapy; Regression
17.  Nitric oxide metabolites in cystic fibrosis lung disease 
Although the activity of nitric oxide (NO) synthases are increased in lung tissue of patients with cystic fibrosis, the concentrations of nasal and exhaled NO have recently been found to be decreased in cystic fibrosis. This could either be due to reduced NO formation or metabolism of NO within airway fluids. In this study, the stable NO metabolites, nitrate and nitrite, were determined in the saliva and sputum of 18 stable cystic fibrosis patients, 21 cystic fibrosis patients during a pulmonary exacerbation, and in saliva and endotracheal secretions of normal controls. Median saliva concentrations of NO metabolites (nitrate plus nitrite) were 704 µmol/l (95% confidence interval (CI) 419 to 1477) in stable cystic fibrosis patients, 629 µmol/l (95% CI 382 to 1392) in cystic fibrosis patients presenting with pulmonary exacerbation, and 313 µmol/l (95% CI 312 to 454) in controls. Median sputum NO metabolite concentration in stable cystic fibrosis was 346 µmol/l (95% CI 311 to 504). This was not significantly different from cystic fibrosis patients presenting with pulmonary exacerbation (median 184 µmol/l, 95% CI 249 to 572), but significantly higher than in endotracheal secretions of controls (median 144 µmol/l, 95% CI 96 to 260). Sputum NO metabolite concentration in cystic fibrosis pulmonary exacerbation significantly increased during antibiotic treatment. A positive correlation was observed between sputum NO metabolites and lung function in stable cystic fibrosis, suggesting less airway NO formation in cystic fibrosis patients with more severe lung disease. These data indicate that decreased exhaled NO concentrations in cystic fibrosis patients may be due to retention and metabolism of NO within the airway secretions. However, sputum NO metabolites are not a useful marker of airway inflammation in cystic fibrosis lung disease.

PMCID: PMC1717443  PMID: 9534676
18.  Extracorporeal Lung Support Technologies – Bridge to Recovery and Bridge to Lung Transplantation in Adult Patients 
Executive Summary
For cases of acute respiratory distress syndrome (ARDS) and progressive chronic respiratory failure, the first choice or treatment is mechanical ventilation. For decades, this method has been used to support critically ill patients in respiratory failure. Despite its life-saving potential, however, several experimental and clinical studies have suggested that ventilator-induced lung injury can adversely affect the lungs and patient outcomes. Current opinion is that by reducing the pressure and volume of gas delivered to the lungs during mechanical ventilation, the stress applied to the lungs is eased, enabling them to rest and recover. In addition, mechanical ventilation may fail to provide adequate gas exchange, thus patients may suffer from severe hypoxia and hypercapnea. For these reasons, extracorporeal lung support technologies may play an important role in the clinical management of patients with lung failure, allowing not only the transfer of oxygen and carbon dioxide (CO2) but also buying the lungs the time needed to rest and heal.
The objective of this analysis was to assess the effectiveness, safety, and cost-effectiveness of extracorporeal lung support technologies in the improvement of pulmonary gas exchange and the survival of adult patients with acute pulmonary failure and those with end-stage chronic progressive lung disease as a bridge to lung transplantation (LTx). The application of these technologies in primary graft dysfunction (PGD) after LTx is beyond the scope of this review and is not discussed.
Clinical Applications of Extracorporeal Lung Support
Extracorporeal lung support technologies [i.e., Interventional Lung Assist (ILA) and extracorporeal membrane oxygenation (ECMO)] have been advocated for use in the treatment of patients with respiratory failure. These techniques do not treat the underlying lung condition; rather, they improve gas exchange while enabling the implantation of a protective ventilation strategy to prevent further damage to the lung tissues imposed by the ventilator. As such, extracorporeal lung support technologies have been used in three major lung failure case types:
As a bridge to recovery in acute lung failure – for patients with injured or diseased lungs to give their lungs time to heal and regain normal physiologic function.
As a bridge to LTx – for patients with irreversible end stage lung disease requiring LTx.
As a bridge to recovery after LTx – used as lung support for patients with PGD or severe hypoxemia.
Ex-Vivo Lung Perfusion and Assessment
Recently, the evaluation and reconditioning of donor lungs ex-vivo has been introduced into clinical practice as a method of improving the rate of donor lung utilization. Generally, about 15% to 20% of donor lungs are suitable for LTx, but these figures may increase with the use of ex-vivo lung perfusion. The ex-vivo evaluation and reconditioning of donor lungs is currently performed at the Toronto General Hospital (TGH) and preliminary results have been encouraging (Personal communication, clinical expert, December 17, 2009). If its effectiveness is confirmed, the use of the technique could lead to further expansion of donor organ pools and improvements in post-LTx outcomes.
Extracorporeal Lung support Technologies
The ECMO system consists of a centrifugal pump, a membrane oxygenator, inlet and outlet cannulas, and tubing. The exchange of oxygen and CO2 then takes place in the oxygenator, which delivers the reoxygenated blood back into one of the patient’s veins or arteries. Additional ports may be added for haemodialysis or ultrafiltration.
Two different techniques may be used to introduce ECMO: venoarterial and venovenous. In the venoarterial technique, cannulation is through either the femoral artery and the femoral vein, or through the carotid artery and the internal jugular vein. In the venovenous technique cannulation is through both femoral veins or a femoral vein and internal jugular vein; one cannula acts as inflow or arterial line, and the other as an outflow or venous line. Venovenous ECMO will not provide adequate support if a patient has pulmonary hypertension or right heart failure. Problems associated with cannulation during the procedure include bleeding around the cannulation site and limb ischemia distal to the cannulation site.
Interventional Lung Assist (ILA) is used to remove excess CO2 from the blood of patients in respiratory failure. The system is characterized by a novel, low-resistance gas exchange device with a diffusion membrane composed of polymethylpentene (PMP) fibres. These fibres are woven into a complex configuration that maximizes the exchange of oxygen and CO2 by simple diffusion. The system is also designed to operate without the help of an external pump, though one can be added if higher blood flow is required. The device is then applied across an arteriovenous shunt between the femoral artery and femoral vein. Depending on the size of the arterial cannula used and the mean systemic arterial pressure, a blood flow of up to 2.5 L/min can be achieved (up to 5.5 L/min with an external pump). The cannulation is performed after intravenous administration of heparin.
Recently, the first commercially available extracorporeal membrane ventilator (NovaLung GmbH, Hechingen, Germany) was approved for clinical use by Health Canada for patients in respiratory failure. The system has been used in more than 2,000 patients with various indications in Europe, and was used for the first time in North America at the Toronto General Hospital in 2006.
Evidence-Based Analysis
The research questions addressed in this report are:
Does ILA/ECMO facilitate gas exchange in the lungs of patients with severe respiratory failure?
Does ILA/ECMO improve the survival rate of patients with respiratory failure caused by a range of underlying conditions including patients awaiting LTx?
What are the possible serious adverse events associated with ILA/ECMO therapy?
To address these questions, a systematic literature search was performed on September 28, 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2005 to September 28, 2008. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with an unknown eligibility were reviewed with a second clinical epidemiologist and then a group of epidemiologists until consensus was established.
Inclusion Criteria
Studies in which ILA/ECMO was used as a bridge to recovery or bridge to LTx
Studies containing information relevant to the effectiveness and safety of the procedure
Studies including at least five patients
Exclusion Criteria
Studies reporting the use of ILA/ECMO for inter-hospital transfers of critically ill patients
Studies reporting the use of ILA/ECMO in patients during or after LTx
Animal or laboratory studies
Case reports
Outcomes of Interest
Reduction in partial pressure of CO2
Correction of respiratory acidosis
Improvement in partial pressure of oxygen
Improvement in patient survival
Frequency and severity of adverse events
The search yielded 107 citations in Medline and 107 citations in EMBASE. After reviewing the information provided in the titles and abstracts, eight citations were found to meet the study inclusion criteria. One study was then excluded because of an overlap in the study population with a previous study. Reference checking did not produce any additional studies for inclusion. Seven case series studies, all conducted in Germany, were thus included in this review (see Table 1).
Also included is the recently published CESAR trial, a multicentre RCT in the UK in which ECMO was compared with conventional intensive care management. The results of the CESAR trial were published when this review was initiated. In the absence of any other recent RCT on ECMO, the results of this trial were considered for this assessment and no further searches were conducted. A literature search was then conducted for application of ECMO as bridge to LTx patients (January, 1, 2005 to current). A total of 127 citations on this topic were identified and reviewed but none were found to have examined the use of ECMO as bridge to LTx.
Quality of Evidence
To grade the quality of evidence, the grading system formulated by the GRADE working group and adopted by MAS was applied. The GRADE system classifies the quality of a body of evidence as high, moderate, low, or very low according to four key elements: study design, study quality, consistency across studies, and directness.
Trials on ILA
Of the seven studies identified, six involved patients with ARDS caused by a range of underlying conditions; the seventh included only patients awaiting LTx. All studies reported the rate of gas exchange and respiratory mechanics before ILA and for up to 7 days of ILA therapy. Four studies reported the means and standard deviations of blood gas transfer and arterial blood pH, which were used for meta-analysis.
Fischer et al. reported their first experience on the use of ILA as a bridge to LTx. In their study, 12 patients at high urgency status for LTx, who also had severe ventilation refractory hypercapnea and respiratory acidosis, were connected to ILA prior to LTx. Seven patients had a systemic infection or sepsis prior to ILA insertion. Six hours after initiation of ILA, the partial pressure of CO2 in arterial blood significantly decreased (P < .05) and arterial blood pH significantly improved (P < .05) and remained stable for one week (last time point reported). The partial pressure of oxygen in arterial blood improved from 71 mmHg to 83 mmHg 6 hours after insertion of ILA. The ratio of PaO2/FiO2 improved from 135 at baseline to 168 at 24 hours after insertion of ILA but returned to baseline values in the following week.
Trials on ECMO
The UK-based CESAR trial was conducted to assess the effectiveness and cost of ECMO therapy for severe, acute respiratory failure. The trial protocol were published in 2006 and details of the methods used for the economic evaluation were published in 2008. The study itself was a pragmatic trial (similar to a UK trial of neonatal ECMO), in which best standard practice was compared with an ECMO protocol. The trial involved 180 patients with acute but potentially reversible respiratory failure, with each also having a Murray score of ≥ 3.0 or uncompensated hypercapnea at a pH of < 7.2. Enrolled patients were randomized in a 1:1 ratio to receive either conventional ventilation treatment or ECMO while on ventilator. Conventional management included intermittent positive pressure ventilation, high frequency oscillatory ventilation, or both. As a pragmatic trial, a specific management protocol was not followed; rather the treatment centres were advised to follow a low volume low pressure ventilation strategy. A tidal volume of 4 to 8 mL/kg body weight and a plateau pressure of < 30 cm H2O were recommended.
Bridge to recovery
No RCTs or observational studies compared ILA to other treatment modalities.
Case series have shown that ILA therapy results in significant CO2 removal from arterial blood and correction of respiratory acidosis, as well as an improvement in oxygen transfer.
ILA therapy enabled a lowering of respiratory settings to protect the lungs without causing a negative impact on arterial blood CO2 and arterial blood pH.
The impact of ILA on patient long-term survival cannot be determined through the studies reviewed.
In-hospital mortality across studies ranged from 20% to 65%.
Ischemic complications were the most frequent adverse events following ILA therapy.
Leg amputation is a rare but possible outcome of ILA therapy, having occurred in about 0.9% of patients in these case series. New techniques involving the insertion of additional cannula into the femoral artery to perfuse the leg may lower this rate.
Bridge to LTx
The results of one case series (n=12) showed that ILA effectively removes CO2 from arterial blood and corrects respiratory acidosis in patients with ventilation refractory hypercapnea awaiting a LTx
Eight of the 12 patients (67%) awaiting a LTx were successfully transplanted and one-year survival for those transplanted was 80%
Since all studies are case series, the grade of the evidence for these observations is classified as “LOW”.
Bridge to recovery
Based on the results of a pragmatic trial and an intention to treat analysis, referral of patient to an ECMO based centre significantly improves patient survival without disability compared to conventional ventilation. The results of CESAR trial showed that:
For patients with information about disability, survival without severe disability was significantly higher in ECMO arm
Assuming that the three patients in the conventional ventilation arm who did not have information about severe disability were all disabled, the results were also significant.
Assuming that none of these patients were disabled, the results were at borderline significance
A greater, though not statistically significant, proportion of patients in ECMO arm survived.
The rate of serious adverse events was higher among patients in ECMO group
The grade of evidence for the above observations is classified as “HIGH”.
Bridge to LTx
No studies fitting the inclusion criteria were identified.
There is no accurate data on the use of ECMO in patients awaiting LTx.
Economic Analysis
The objective of the economic analysis was to determine the costs associated with extracorporeal lung support technologies for bridge to LTx in adults. A literature search was conducted for which the target population was adults eligible for extracorporeal lung support. The primary analytic perspective was that of the Ministry of Health and Long-Term Care (MOHLTC). Articles published in English and fitting the following inclusion criteria were reviewed:
Full economic evaluations including cost-effectiveness analyses (CEA), cost-utility analyses (CUA), cost-benefit analyses (CBA);
Economic evaluations reporting incremental cost-effectiveness ratios (ICER) i.e. cost per quality adjusted life year (QALY), life years gained (LYG), or cost per event avoided; and
Studies in patients eligible for lung support technologies for to lung transplantation.
The search yielded no articles reporting comparative economic analyses.
Resource Use and Costs
Costs associated with both ILA and ECMO (outlined in Table ES-1) were obtained from the University Health Network (UHN) case costing initiative (personal communication, UHN, January 2010). Consultation with a clinical expert in the field was also conducted to verify resource utilization. The consultant was situated at the UHN in Toronto. The UHN has one ECMO machine, which cost approximately $100,000. The system is 18 years old and is used an average of 3 to 4 times a year with 35 procedures being performed over the last 9 years. The disposable cost per patient associated with ECMO is, on average, $2,200. There is a maintenance cost associated with the machine (not reported by the UHN), which is currently absorbed by the hospital’s biomedical engineering department.
The average capital cost of an ILA device is $7,100 per device, per patient, while the average cost of the reusable pump $65,000. The UHN has performed 16 of these procedures over the last 2.5 years. Similarly, there is a maintenance cost not that was reported by UHN but is absorbed by the hospital’s biomedical engineering department.
Resources Associated with Extracorporeal Lung Support Technologies
Hospital costs associated with ILA were based on the average cost incurred by the hospital for 11 cases performed in the FY 07/08 (personal communication, UHN, January 2010). The resources incurred with this hospital procedure included:
Device and disposables
OR transplant
Surgical ICU
Laboratory work
Medical imaging
Clinical nutrition
Occupational therapy
Speech and language pathology
Social work
The average length of stay in hospital was 61 days for ILA (range: 5 to 164 days) and the average direct cost was $186,000 per case (range: $19,000 to $552,000). This procedure has a high staffing requirement to monitor patients in hospital, driving up the average cost per case.
PMCID: PMC3415698  PMID: 23074408
19.  Open randomised prospective comparative multi-centre intervention study of patients with cystic fibrosis and early diagnosed diabetes mellitus 
BMC Pediatrics  2014;14:70.
Diabetes mellitus may be present in patients with cystic fibrosis starting in the second decade of life. The prevalence increases rapidly with increasing age. As life-expectancy increases in cystic fibrosis, cystic fibrosis related diabetes will be diagnosed more frequently in the future.
Up to date, no data are available to answer the question if cystic fibrosis related diabetes should always initially be treated by insulin therapy. Missing data regarding oral antidiabetic treatment of newly diagnosed cystic fibrosis related diabetes are an important reason to recommend insulin treatment. Several centres report the successful management of cystic fibrosis related diabetes using oral anti-diabetic drugs at least for some years. Oral therapies would be less invasive for a patient group which is highly traumatized by a very demanding therapy. Based on an initiative of the German Mukoviszidosis-Foundation, the present study tries to answer the question, whether oral therapy with repaglinide is as effective as insulin therapy in cystic fibrosis patients with early diagnosed diabetes mellitus.
In all cystic fibrosis patients with an age of 10 years or older, an oral glucose tolerance test is recommended. The result of this test is classified according to the WHO cut off values. It is required to have two diabetes positive oral glucose tolerance tests for the diagnosis of diabetes mellitus.
This study is a multi-national, multicentre, open labelled, randomized and prospective controlled parallel group’s trial, with 24 months treatment.
The primary objective of this trial is to compare the glycaemic control of oral therapy with Repaglinide with insulin injections in patients with cystic fibrosis related diabetes after 2 years of treatment.
The trial should include 74 subjects showing cystic fibrosis related diabetes newly diagnosed by oral glucose tolerance test during annual screening for cystic fibrosis related diabetes.
Patients are randomised by central fax randomisation.
Primary endpoint is mean HbA1c after 24 months of treatment. Secondary endpoints are change in FEV1% predicted and change in BMI-Z-score.
There is only one prospective study comparing oral antidiabetic drugs to insulin in the treatment of CFRD without fasting hyperglycaemia. The results regarding BMI after 6 months and 12 months showed an improvement for the insulin treated patients and were inconsistent for those treated with repaglinide. HbA1c and lung function (FEV1%pred) were unchanged for either group. The authors compared the changes -12 months to baseline and baseline to +12 months separately for each group. Therefore a direct comparison of the effect of repaglinide versus insulin on BMI, HbA1c and FEV1%pred was not presented. According to our protocol, we will directly compare treatment effects (HbA1c, BMI, FEV1%pred) in between both groups. The actual Cochrane report regarding “Insulin and oral agents for managing CFRD” stated that further studies are needed to establish whether there is clear benefit for hypoglycemic agents. We expect that the results of our study will help to address this clinical need.
Trial registration Identifier: NCT00662714
PMCID: PMC3975280  PMID: 24620855
Cystic fibrosis; Diabetes mellitus; Lung diseases; Genetic diseases; Inborn; Repaglinide; Insulin; HbA1c; Clinical trial
20.  Azithromycin reduces spontaneous and induced inflammation in ΔF508 cystic fibrosis mice 
Respiratory Research  2006;7(1):134.
Inflammation plays a critical role in lung disease development and progression in cystic fibrosis. Azithromycin is used for the treatment of cystic fibrosis lung disease, although its mechanisms of action are poorly understood. We tested the hypothesis that azithromycin modulates lung inflammation in cystic fibrosis mice.
We monitored cellular and molecular inflammatory markers in lungs of cystic fibrosis mutant mice homozygous for the ΔF508 mutation and their littermate controls, either in baseline conditions or after induction of acute inflammation by intratracheal instillation of lipopolysaccharide from Pseudomonas aeruginosa, which would be independent of interactions of bacteria with epithelial cells. The effect of azithromycin pretreatment (10 mg/kg/day) given by oral administration for 4 weeks was evaluated.
In naive cystic fibrosis mice, a spontaneous lung inflammation was observed, characterized by macrophage and neutrophil infiltration, and increased intra-luminal content of the pro-inflammatory cytokine macrophage inflammatory protein-2. After induced inflammation, cystic fibrosis mice combined exaggerated cellular infiltration and lower anti-inflammatory interleukin-10 production. In cystic fibrosis mice, azithromycin attenuated cellular infiltration in both baseline and induced inflammatory condition, and inhibited cytokine (tumor necrosis factor-α and macrophage inflammatory protein-2) release in lipopolysaccharide-induced inflammation.
Our findings further support the concept that inflammatory responses are upregulated in cystic fibrosis. Azithromycin reduces some lung inflammation outcome measures in cystic fibrosis mice. We postulate that some of the benefits of azithromycin treatment in cystic fibrosis patients are due to modulation of lung inflammation.
PMCID: PMC1637104  PMID: 17064416
21.  Gene therapy for the treatment of cystic fibrosis 
Gene therapy is being developed as a novel treatment for cystic fibrosis (CF), a condition that has hitherto been widely-researched yet for which no treatment exists that halts the progression of lung disease. Gene therapy involves the transfer of correct copies of cystic fibrosis transmembrane conductance regulator (CFTR) DNA to the epithelial cells in the airways. The cloning of the CFTR gene in 1989 led to proof-of-principle studies of CFTR gene transfer in vitro and in animal models. The earliest clinical trials in CF patients were conducted in 1993 and used viral and non-viral gene transfer agents in both the nasal and bronchial airway epithelium. To date, studies have focused largely on molecular or bioelectric (chloride secretion) outcome measures, many demonstrating evidence of CFTR expression, but few have attempted to achieve clinical efficacy. As CF is a lifelong disease, turnover of the airway epithelium necessitates repeat administration. To date, this has been difficult to achieve with viral gene transfer agents due to host recognition leading to loss of expression. The UK Cystic Fibrosis Gene Therapy Consortium (Imperial College London, University of Edinburgh and University of Oxford) is currently working on a large and ambitious program to establish the clinical benefits of CF gene therapy. Wave 1, which has reached the clinic, uses a non-viral vector. A single-dose safety trial is nearing completion and a multi-dose clinical trial is shortly due to start; this will be powered for clinically-relevant changes. Wave 2, more futuristically, will look at the potential of lentiviruses, which have long-lasting expression. This review will summarize the current status of translational research in CF gene therapy.
PMCID: PMC3681190  PMID: 23776378
cystic fibrosis transmembrane conductance regulator (CFTR) gene; gene expression; gene transfer agents (GTAs); outcome measures
22.  Renal Cell Protection of Erythropoietin beyond Correcting The Anemia in Chronic Kidney Disease Patients 
Cell Journal (Yakhteh)  2013;15(4):378-380.
Currently many patients with chronic renal failure have profited from the use of erythropoietin to correct anemia (1,2). In chronic kidney disease, anemia is believed to be a surrogate index for tissue hypoxia that continues preexisting renal tissue injury (1-3). Erythropoietin is an essential glycoprotein that accelerates red blood cell maturation from erythroid progenitors and facilitates erythropoiesis. It is a 30.4 kD glycoprotein and class I cytokine containing 165 amino acids (3,4). Approximately 90% of systemic erythropoietin in adults is produced by peritubular interstitial fibroblasts in the renal cortex and outer medulla of the kidney (3-5). A feedback mechanism involving oxygen delivery to the tissues seems to regulate erythropoietin production. Hypoxia-inducible factor regulates transcription of the erythropoietin gene in the kidney, which determines erythropoietin synthesis (3-5). Erythropoietin is an essential glycoprotein that accelerates red blood cell maturation from erythroid progenitors and mediates erythropoiesis in the bone marrow (4-6). Kidney fibrosis is the last common pathway in chronic renal failure irrespective of the initial etiology (5,6). Constant inflammatory cell infiltration and pericyte-myofibroblast transition lead to renal fibrosis and insufficiency which result in decreased production of erythropoietin (4-7). Thus far, therapeutic efforts to treat patients with chronic renal failure by administering erythropoietin have been made only to correct anemia and putative hypoxic tissue damage. The introduction of recombinant human erythropoietin has marked a significant advance in the management of anemia associated with chronic renal failure (6-9). With an increasing number of patients with chronic renal failure receiving erythropoietin treatment, emerging evidence suggests that erythropoietin not only has an erythropoietic function, but also has renoprotective potential. In fact, in recent years, the additional non-erythropoietic tissue/ organ protective efficacy of erythropoietin has become evident, especially in the kidneys (5-12). Various investigations have shown the kidney protective property of erythropoietin in acute kidney injury. In a study to evaluate the ameliorative effects of erythropoietin on renal tubular cells, we studied 40 male rats. We found that erythropoietin was able to prevent the increase in serum creatinine and blood urea nitrogen. Furthermore, co-administration of gentamicin and erythropoietin effectively reduced kidney tissue damage compared to the control group. However, the protective properties of erythropoietin were also evident in our study. When the drug was applied after gentamicin- induced tubular damage we were able to show that the drug was still effective after tissue injury onset. This indicates that erythropoietin may have curative effects in addition to its preventive properties (13). Thus, erythropoietin is a promising kidney protective agent to prevent, ameliorate or attenuate tubular damage induced by gentamicin or other nephrotoxic agents that act in a similar manner to this drug (14-17). Recent studies have elucidated the cellular mechanism involved in kidney erythropoietin production and the consequent events that lead to kidney fibrosis, showing that they are closely related to each other (18-20). In contrast to previous findings, fibroblasts originating from damaged renal tubular epithelial cells do not have an important role in kidney fibrosis, but renal erythropoietin- producing cells, stemming from neural crests, have been shown to trans-differentiate into myofibroblasts after long-term exposure to inflammatory situations related to kidney fibrosis. In fact, almost all myofibroblasts expressing α-smooth muscle actin originate from renal erythropoietin-producing cells, which are naturally peritubular interstitial fibroblastic cells expressing neural cell marker genes but not α-smooth muscle actin. Macrophages and myofibroblasts are responsible for fibrosis in the renal tissue. Macrophages could be differentiated to phenotype M1 (classically activated) or M2 (wound healing) according to the distinctive cytokine production and behavior that follows different routes of activation (6,8,21,22). While erythropoietin can disengage macrophages by stopping the activity of NF-κB, it is possible that one of the mechanisms explaining the antifibrotic effects of erythropoietin in chronic kidney disease is in vivo macrophage regulation (20-25). These important findings stipulate the missing link in chronic renal failure between anemia and kidney fibrosis (6,8,21,22). In patients with chronic kidney disease, anemia due to reduced erythropoietin production eventually appears (1,4,5). Recombinant human erythropoietin has been used for more than 20 years in chronic kidney disease to recompense for reduced endogenous erythropoietin production (1,4,5,25). Recent investigations have pointed out that erythropoietin administration improves kidney functions in chronic kidney disease either directly or indirectly (17-24). The therapeutic benefits of erythropoietin beyond the correction of anemia are still questioned. However, it is notable that various pieces of evidence simply reflect the pleiotropic effects of erythropoietinon on the central nervous, cardiovascular system and on the kidney (18,20,25). In brief, clinical evidence shows the kidney protective potential of erythropoietin in patients with chronic renal failure, however, additional clinical investigations are crucial to outline when to start erythropoietin treatment and what is the optimal erythropoietin dosage for slowing disease progression in patients with chronic renal failure. The application of erythropoietin treatment for renoprotection may need to be earlier than that for erythropoiesis, while it is possible that the erythropoietin attenuation of renal fibrosis through macrophage regulation and endothelial cell protection operates through other unidentified mechanisms. While agents restoring the initial function of renal erythropoietin-producing cells could delay kidney fibrosis, further laboratory studies are necessary to clarify the cellular target of erythropoietin in the kidney and for developing a novel erythropoietin derivative or mimetic for kidney protection.
PMCID: PMC3866543  PMID: 24381864
Erythropoietin; Erythropoiesis
23.  Stratified assessment of the role of inhaled hypertonic saline in reducing cystic fibrosis pulmonary exacerbations: a retrospective analysis 
BMJ Open  2011;1(1):e000019.
Limited data exist concerning the role of inhaled hypertonic saline (HS) in decreasing pulmonary exacerbations in cystic fibrosis (CF), especially as more advanced stages of CF lung disease were excluded in prior studies. Herein, the authors retrospectively determined the efficacy of inhaled HS in reducing CF pulmonary exacerbations when stratified according to the severity of CF lung disease. Stratification was based on the framework of the Pulmonary Therapeutics Committee's published gradation of obstructive lung physiology in CF, that is, mild (FEV1 >70%), moderate (FEV1 40–70%) and severe (FEV1 <40%) lung disease, respectively.
A retrospective review of the Port CF database over a 3-year period performed at an academic CF care centre.
340 pulmonary exacerbations were identified; inhaled HS was being used in 99 of these cases. Univariate analysis demonstrated a significant reduction in pulmonary exacerbations only in mild obstruction (OR=0.09, CI 0.01 to 0.81, p=0.012); however, multivariate logistic regression that adjusted for confounding variables showed a reduction in pulmonary exacerbations across the entire spectrum of obstructive lung disease when using inhaled HS, that is, mild obstructive CF lung disease (OR=0.17, CI 0.05 to 0.58, p=0.004), moderate obstructive CF lung disease (OR=0.39, CI 0.16 to 0.93, p=0.034), as well as severe obstructive CF lung disease (OR=0.02, CI 0.001 to 0.45, p=0.015). Moreover, inhaled HS appeared reasonably well tolerated across all stages of lung-disease severity, and was discontinued in only 7% of cases (n=4) with severe lung disease.
In this study, inhaled HS appeared to reduce pulmonary exacerbations in CF lung disease at all stages of obstruction. This underscores the importance of therapeutic inhaled HS in CF lung disease, regardless of the severity of lung obstruction.
Article summary
Article focus
Prior studies have demonstrated that inhaled hypertonic saline (HS) improves the forced expiratory volume in 1 s (FEV1) and the forced vital capacity (FVC) in patients with cystic fibrosis.
Inhaled HS also decreases the frequency of pulmonary exacerbations in cystic fibrosis; this aspect has been less extensively studied, especially in more severe forms of disease.
This study focuses on the role of inhaled HS in decreasing the frequency of pulmonary exacerbations in patients stratified according to the severity of CF lung disease.
Key messages
This study suggests that inhaled HS may be beneficial in reducing pulmonary exacerbations at all stages of CF lung disease severity, thus highlighting the importance of inhaled HS as a key component of the CF therapeutic armamentarium.
The observed benefit of inhaled HS appeared in addition to that of established airway clearance strategies such as nebulised rhDNase therapy and mechanical airway clearance devices.
This study found no indication of any excessive discontinuation of inhaled HS due to cough or bronchospasm in more severe forms of CF lung disease, suggesting that it is reasonably well tolerated even in such cases.
Strengths and limitations of this study
This study establishes the role of inhaled HS in reducing the number of pulmonary exacerbations at more advanced stages of CF lung disease severity, which is of special significance considering that the more severe forms of CF lung disease had been excluded in previous studies.
Our study group had a significantly higher usage of nebulised rhDNase (100%) and other mechanical airway clearance therapies (97%) compared with previous studies, thus supporting the additional beneficial effect of inhaled HS.
Our two study groups had differences in epidemiological characteristics, potentially introducing bias into the results. We have attempted to minimise for this by performing a logistic regression; however, we acknowledge the inherent limitations of such a retrospective study design.
PMCID: PMC3191387  PMID: 22021727
Cystic fibrosis; intensive care; respiratory
24.  Severe Hypercapnia in Critically Ill Adult Cystic Fibrosis Patients 
Cystic fibrosis (CF) is a monogenetic autosomal recessive multi-organ disease affecting approximately 50,000 patients worldwide. Overall median survival is continually increasing but pulmonary disease remains the most common cause of death. Guidelines have been published in relation to the outpatient maintenance of lung health for CF patients and treatment of acute lung exacerbations but little information exists about the management of the critically ill CF patient. Invasive mechanical ventilation in CF patients with acute respiratory failure is associated with poor outcome and high mortality.
Retrospective analysis of adult patients with CF who required endotracheal intubation and invasive mechanical ventilation in the Medical Intensive Care Unit (MICU).
Between the years 2003 - 2009, 14 adult patients with CF required endotracheal intubation and invasive mechanical ventilation in the Medical Intensive Care Unit (MICU) of the Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA. Eleven patients died in the MICU because of progressive respiratory failure and inability to liberate from mechanical ventilation. Seven individuals consistently manifested arterial partial pressures of carbon dioxide (PaCO2) greater than 20.00 kPa despite high levels of conventional modes of mechanical ventilation.
Intubated CF patients with respiratory failure have a high mortality rate. Based on our experience, multiple factors contribute to severe hypercapnia and the effectiveness of conventional modes of mechanical ventilation in many of these patients is limited.
Cystic fibrosis; Mechanical ventilation; Critical care; Hypercapnia; Respiratory failure
PMCID: PMC3279481  PMID: 22383907
25.  Ciliary Beating Recovery in Deficient Human Airway Epithelial Cells after Lentivirus Ex Vivo Gene Therapy 
PLoS Genetics  2009;5(3):e1000422.
Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1) gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1–deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT–PCR and western blot, respectively. Human airway epithelial cells that were DNAI1–deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease.
Author Summary
This manuscript reports on a successful gene therapy attempt on human airway epithelial cells of a patient suffering from Primary Ciliary Dyskinesia. In this autosomal recessive disease, cilia of the epithelial cells that border the upper and lower respiratory tracks are not functioning. As a result, patients suffer from recurrent airway infections leading progressively to respiratory insufficiency. There is no treatment as of today that could restore normal ciliary beating. In this report, we showed that it is feasible to transfer a therapeutic gene to human airway epithelial cells with a lentivirus. This transferred gene is transcribed and expressed. Moreover, defective cells that had immotile cilia due to compound heterozygous mutations in the DNAI1 gene recovered ciliary beating after treatment with a lentivirus containing a normal DNAI1 gene. This is the first report on gene therapy in Primary Ciliary Dyskinesia. Since lentivirus is able to insert therapeutic genes into the cell genome, this result may have impact on in vivo gene therapy in this disease and in diseases related to human epithelial airway cells such as cystic fibrosis.
PMCID: PMC2650261  PMID: 19300481

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