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1.  Increased respiratory drive relates to severity of dyspnea in systemic sclerosis 
Dyspnea may be a presenting symptom in progressive systemic sclerosis (SSc). Respiratory drive (mouth occlusion pressure, MOP, at rest and during CO2 rebreathing, 7% CO2, 93% O2) is a major determinant of dyspnea and may relate to the magnitude of dyspnea.
In a prospective design, MOP at 0.1 sec (P0.1) was measured in 73 SSc patients while breathing room air and during CO2 rebreathing. An abnormal V’E/P0.1 is defined as < 8 L/min/cm H2O. Dyspnea scores were assessed by a shortness of breath questionnaire (UCSD dyspnea scale).
Mean P0.1 in patients with normal V’E/P0.1 (n = 45) was 1.1 ± 0.04 and 1.6 ± 0.08 cm H2O in patients with abnormal V’E/P0.1 (n = 28), p <0.001. ∆P0.1/∆PetCO2 differed significantly between these groups (0.45 versus 0.75 cm H2O/mmHg, P < 0.001), but no significant difference was present in ∆V’E/∆PetCO2. V’E/P0.1 showed the highest significant correlation with the UCSD dyspnea score (r = -0.76, p <0.001). UCSD cut-off value for abnormal V’E/P0.1 was 8.5 (sensitivity 93%, specificity 96%, area under the curve 0.98).
In SSc patients an abnormal V’E/P0.1 better relates to the severity of dyspnea than traditional lung function parameters and can easily be assessed at first outpatient consultation.
PMCID: PMC3986445  PMID: 24708492
Respiratory drive; Systemic sclerosis; Dyspnea evaluation
2.  Increased ERK signalling promotes inflammatory signalling in primary airway epithelial cells expressing Z α1-antitrypsin 
Human Molecular Genetics  2013;23(4):929-941.
Overexpression of Z α1-antitrypsin is known to induce polymer formation, prime the cells for endoplasmic reticulum stress and initiate nuclear factor kappa B (NF-κB) signalling. However, whether endogenous expression in primary bronchial epithelial cells has similar consequences remains unclear. Moreover, the mechanism of NF-κB activation has not yet been elucidated. Here, we report excessive NF-κB signalling in resting primary bronchial epithelial cells from ZZ patients compared with wild-type (MM) controls, and this appears to be mediated by mitogen-activated protein/extracellular signal-regulated kinase, EGF receptor and ADAM17 activity. Moreover, we show that rather than being a response to protein polymers, NF-κB signalling in airway-derived cells represents a loss of anti-inflammatory signalling by M α1-antitrypsin. Treatment of ZZ primary bronchial epithelial cells with purified plasma M α1-antitrypsin attenuates this inflammatory response, opening up new therapeutic options to modulate airway inflammation in the lung.
PMCID: PMC4007119  PMID: 24097797
3.  Profiling the Proteome of Exhaled Breath Condensate in Healthy Smokers and COPD Patients by LC-MS/MS 
Three pools of exhaled breath condensate (EBC) from non-smokers plus healthy smokers (NS + HS, n = 45); chronic obstructive pulmonary disease (COPD) without emphysema (COPD, n = 15) and subjects with pulmonary emphysema associated with α1-antitrypsin deficiency (AATD, n = 23) were used for an exploratory proteomic study aimed at generating fingerprints of these groups that can be used in future pathophysiological and perhaps even clinical research. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was the platform applied for this hypothesis-free investigation. Analysis of pooled specimens resulted in the production of a “fingerprint” made of 44 proteins for NS/HS; 17 for COPD and 15 for the group of AATD subjects. Several inflammatory cytokines (IL-1α, IL-1β, IL-2; IL-12, α and β subunits, IL-15, interferon α and γ, tumor necrosis factor α); Type I and II cytokeratins; two SP-A isoforms; Calgranulin A and B and α1-antitrypsin were detected and validated through the use of surface enhanced laser-desorption ionization mass spectrometry (SELDI-MS) and/or by Western blot (WB) analysis. These results are the prelude of quantitative studies aimed at identifying which of these proteins hold promise as identifiers of differences that could distinguish healthy subjects from patients.
PMCID: PMC3509556  PMID: 23203040
EBC; COPD; proteomics; LC-MS/MS
4.  A quantitative method for detection of spliced X-box binding protein-1 (XBP1) mRNA as a measure of endoplasmic reticulum (ER) stress 
Cell Stress & Chaperones  2011;17(2):275-279.
Endoplasmic reticulum (ER) stress is increasingly recognized as an important mechanism in a wide range of diseases including cystic fibrosis, alpha-1 antitrypsin deficiency, Parkinson's and Alzheimer's disease. Therefore, there is an increased need for reliable and quantitative markers for detection of ER stress in human tissues and cells. Accumulation of unfolded or misfolded proteins in the endoplasmic reticulum can cause ER stress, which leads to the activation of the unfolded protein response (UPR). UPR signaling involves splicing of X-box binding protein-1 (XBP1) mRNA, which is frequently used as a marker for ER stress. In most studies, the splicing of the XBP1 mRNA is visualized by gel electrophoresis which is laborious and difficult to quantify. In the present study, we have developed and validated a quantitative real-time RT-PCR method to detect the spliced form of XBP1 mRNA.
PMCID: PMC3273559  PMID: 22038282
ER stress; Spliced XBP1; Real-time RT-PCR; BiP; CHOP; Primary bronchial epithelial cells
5.  The role of IREB2 and transforming growth factor beta-1 genetic variants in COPD: a replication case-control study 
BMC Medical Genetics  2011;12:24.
Genetic factors are known to contribute to COPD susceptibility and these factors are not fully understood. Conflicting results have been reported for many genetic studies of candidate genes based on their role in the disease. Genome-wide association studies in combination with expression profiling have identified a number of new candidates including IREB2. A meta-analysis has implicated transforming growth factor beta-1 (TGFbeta1) as a contributor to disease susceptibility.
We have examined previously reported associations in both genes in a collection of 1017 white COPD patients and 912 non-diseased smoking controls. Genotype information was obtained for seven SNPs in the IREB2 gene, and for four SNPs in the TGFbeta1 gene. Allele and genotype frequencies were compared between COPD cases and controls, and odds ratios were calculated. The analysis was adjusted for age, sex, smoking and centre, including interactions of age, sex and smoking with centre.
Our data replicate the association of IREB2 SNPs in association with COPD for SNP rs2568494, rs2656069 and rs12593229 with respective adjusted p-values of 0.0018, 0.0039 and 0.0053. No significant associations were identified for TGFbeta1.
These studies have therefore confirmed that the IREB2 locus is a contributor to COPD susceptibility and suggests a new pathway in COPD pathogenesis invoking iron homeostasis.
PMCID: PMC3047296  PMID: 21320324
6.  Therapeutic efficacy of alpha-1 antitrypsin augmentation therapy on the loss of lung tissue: an integrated analysis of 2 randomised clinical trials using computed tomography densitometry 
Respiratory Research  2010;11(1):136.
Two randomised, double-blind, placebo-controlled trials have investigated the efficacy of IV alpha-1 antitrypsin (AAT) augmentation therapy on emphysema progression using CT densitometry.
Data from these similar trials, a 2-center Danish-Dutch study (n = 54) and the 3-center EXAcerbations and CT scan as Lung Endpoints (EXACTLE) study (n = 65), were pooled to increase the statistical power. The change in 15th percentile of lung density (PD15) measured by CT scan was obtained from both trials. All subjects had 1 CT scan at baseline and at least 1 CT scan after treatment. Densitometric data from 119 patients (AAT [Alfalastin® or Prolastin®], n = 60; placebo, n = 59) were analysed by a statistical/endpoint analysis method. To adjust for lung volume, volume correction was made by including the change in log-transformed total lung volume as a covariate in the statistical model.
Mean follow-up was approximately 2.5 years. The mean change in lung density from baseline to last CT scan was -4.082 g/L for AAT and -6.379 g/L for placebo with a treatment difference of 2.297 (95% CI, 0.669 to 3.926; p = 0.006). The corresponding annual declines were -1.73 and -2.74 g/L/yr, respectively.
The overall results of the combined analysis of 2 separate trials of comparable design, and the only 2 controlled clinical trials completed to date, has confirmed that IV AAT augmentation therapy significantly reduces the decline in lung density and may therefore reduce the future risk of mortality in patients with AAT deficiency-related emphysema.
Trial registration
The EXACTLE study was registered in as 'Antitrypsin (AAT) to Treat Emphysema in AAT-Deficient Patients'; Identifier: NCT00263887.
PMCID: PMC2964614  PMID: 20920370
7.  A disintegrin and metalloprotease 33 and chronic obstructive pulmonary disease pathophysiology 
Thorax  2006;62(3):242-247.
Chronic obstructive pulmonary disease (COPD) is a respiratory disorder with increasing prevalence and mortality. It is associated with airway obstruction, increased airway hyper‐responsiveness (AHR), and ongoing airway and lung inflammation dominated by CD8 lymphocytes and neutrophils. Single‐nucleotide polymorphisms (SNPs) in a disintegrin and metalloprotease 33 (ADAM33) gene have been associated with AHR and COPD.
To assess whether SNPs in ADAM33 are associated with the severity of AHR and airway inflammation in COPD.
Eight SNPs in ADAM33 (F+1, Q‐1, S_1, S_2, ST+5, T_1, T_2, V_4) were genotyped in 111 patients with COPD (96 males, 69 current smokers, mean (standard deviation (SD)), aged 62 (8) years, median pack‐years 42 (IQR 31–55), mean postbronchodilator forced expiratory volume in 1 s (FEV1)% predicted 63 (9). Provocative concentration of methacholine causing a decrease in FEV1 of 20% (PC20 methacholine), sputum and bronchial biopsies were collected.
Patients with the ST+5 AA genotype had more severe AHR, higher numbers of sputum inflammatory cells and CD8 cells in bronchial biopsies than patients with the GG genotype (p = 0.03, 0.05 and 0.01, respectively). CD8 cell numbers were lower in patients carrying the minor allele of SNP T_1 and T_2, and homozygotic minor variants of SNP S_2 compared with the wild type (p = 0.02, 0.01 and 0.02, respectively).
This is the first study revealing that SNPs in a gene that confers susceptibility to COPD in the general population—that is, ADAM33—are associated with AHR and airway inflammation in COPD. These findings constitute an important step forward in linking gene polymorphisms with COPD pathophysiology, thereby possibly contributing to better treatments for this progressive and disabling disease in the future.
PMCID: PMC2117167  PMID: 17090574
8.  Association of MMP - 12 polymorphisms with severe and very severe COPD: A case control study of MMPs - 1, 9 and 12 in a European population 
BMC Medical Genetics  2010;11:7.
Genetic factors play a role in chronic obstructive pulmonary disease (COPD) but are poorly understood. A number of candidate genes have been proposed on the basis of the pathogenesis of COPD. These include the matrix metalloproteinase (MMP) genes which play a role in tissue remodelling and fit in with the protease - antiprotease imbalance theory for the cause of COPD. Previous genetic studies of MMPs in COPD have had inadequate coverage of the genes, and have reported conflicting associations of both single nucleotide polymorphisms (SNPs) and SNP haplotypes, plausibly due to under-powered studies.
To address these issues we genotyped 26 SNPs, providing comprehensive coverage of reported SNP variation, in MMPs- 1, 9 and 12 from 977 COPD patients and 876 non-diseased smokers of European descent and evaluated their association with disease singly and in haplotype combinations. We used logistic regression to adjust for age, gender, centre and smoking history.
Haplotypes of two SNPs in MMP-12 (rs652438 and rs2276109), showed an association with severe/very severe disease, corresponding to GOLD Stages III and IV.
Those with the common A-A haplotype for these two SNPs were at greater risk of developing severe/very severe disease (p = 0.0039) while possession of the minor G variants at either SNP locus had a protective effect (adjusted odds ratio of 0.76; 95% CI 0.61 - 0.94). The A-A haplotype was also associated with significantly lower predicted FEV1 (42.62% versus 44.79%; p = 0.0129). This implicates haplotypes of MMP-12 as modifiers of disease severity.
PMCID: PMC2820470  PMID: 20078883
9.  Hereditary alpha-1-antitrypsin deficiency and its clinical consequences 
Alpha-1-antitrypsin deficiency (AATD) is a genetic disorder that manifests as pulmonary emphysema, liver cirrhosis and, rarely, as the skin disease panniculitis, and is characterized by low serum levels of AAT, the main protease inhibitor (PI) in human serum. The prevalence in Western Europe and in the USA is estimated at approximately 1 in 2,500 and 1 : 5,000 newborns, and is highly dependent on the Scandinavian descent within the population. The most common deficiency alleles in North Europe are PI Z and PI S, and the majority of individuals with severe AATD are PI type ZZ. The clinical manifestations may widely vary between patients, ranging from asymptomatic in some to fatal liver or lung disease in others. Type ZZ and SZ AATD are risk factors for the development of respiratory symptoms (dyspnoea, coughing), early onset emphysema, and airflow obstruction early in adult life. Environmental factors such as cigarette smoking, and dust exposure are additional risk factors and have been linked to an accelerated progression of this condition. Type ZZ AATD may also lead to the development of acute or chronic liver disease in childhood or adulthood: prolonged jaundice after birth with conjugated hyperbilirubinemia and abnormal liver enzymes are characteristic clinical signs. Cirrhotic liver failure may occur around age 50. In very rare cases, necrotizing panniculitis and secondary vasculitis may occur. AATD is caused by mutations in the SERPINA1 gene encoding AAT, and is inherited as an autosomal recessive trait. The diagnosis can be established by detection of low serum levels of AAT and isoelectric focusing. Differential diagnoses should exclude bleeding disorders or jaundice, viral infection, hemochromatosis, Wilson's disease and autoimmune hepatitis. For treatment of lung disease, intravenous alpha-1-antitrypsin augmentation therapy, annual flu vaccination and a pneumococcal vaccine every 5 years are recommended. Relief of breathlessness may be obtained with long-acting bronchodilators and inhaled corticosteroids. The end-stage liver and lung disease can be treated by organ transplantation. In AATD patients with cirrhosis, prognosis is generally grave.
PMCID: PMC2441617  PMID: 18565211
10.  Pulmonary stem cells and the induction of tissue regeneration in the treatment of emphysema 
A common feature of lung disorders with poor treatment options, including emphysema, is a failure to initiate a repair process of the alveolar epithelium. Several putative stem cell niches in the lung thought to be involved in lung homeostasis have been described. Apparently, under pathophysiological conditions these resident progenitor cells are unable to recover damaged alveolar epithelium, in particular in emphysema. The potential therapeutic effect of retinoic acid receptor agonists on various resident lung progenitor cells is reviewed.
PMCID: PMC2695612  PMID: 18044685
alveolar growth; repair; emphysema
11.  Alpha1-antitrypsin deficiency: current perspective on research, diagnosis, and management 
The Alpha One International Registry (AIR), a multinational research program focused on alpha1-antitrypsin (AAT) deficiency, was formed in response to a World Health Organization recommendation. Each of the nearly 20 participating countries maintains a national registry of patients with AAT deficiency and contributes to an international database located in Malmö, Sweden. This database is designed to increase understanding of AAT deficiency. Additionally, AIR members are engaged in active, wide-ranging investigations to improve the diagnosis, monitoring, and treatment of the disease and meet biennially to exchange views and research findings. The fourth biennial meeting was held in Copenhagen, Denmark, on 2–3 June 2005. This review covers the wide range of AAT deficiency-related topics that were addressed encompassing advances in genetic characterization, risk factor identification, clinical epidemiology, inflammatory and signalling processes, therapeutic advances, and lung imaging techniques.
PMCID: PMC2706616  PMID: 18046892
alpha1-antitrypsin deficiency; epidemiology; polymorphism; genetics; augmentation therapy
12.  Correction: Short-term variability of biomarkers of proteinase activity in patients with emphysema associated with type Z alpha-1-antitrypsin deficiency 
Respiratory Research  2006;7(1):20.
After the publication of this work [1], we became aware of the fact that one author was missing on the author list. Dr Jo.H.M. Berden contributed the JM403 antibody and advised on the methodology for the ELISA for JM403. He also contributed to the text of the manuscript.
Apart from this correction concerning the authorship, the methods and interpretation of the data, the results reported in our publication and the conclusions are absolutely correct.
We apologize for the inconvenience that this inaccuracy may have caused.
PMCID: PMC1379638
13.  Short-term variability of biomarkers of proteinase activity in patients with emphysema associated with type Z alpha-1-antitrypsin deficiency 
Respiratory Research  2005;6(1):47.
The burden of proteinases from inflammatory cells in the lung of subjects with type Pi ZZ of alpha-1-antitrypsin deficiency is higher than in those without the deficiency. Cross-sectional studies have shown increased levels of biomarkers of extracellular matrix degradation in vivo. Longitudinal variability of these biomarkers is unknown but desirable for clinical studies with proteinase inhibitors.
We measured three different types of biomarkers, including desmosines, elastase-formed fibrinogen fragments and heparan sulfate epitope JM403, in plasma and urine for a period of 7 weeks in a group of 12 patients who participated in a placebo-controlled study to assess the safety of a single inhalation of hyaluronic acid.
Effect of study medication on any of the biomarkers was not seen. Baseline desmosines in plasma and urine correlated with baseline CO diffusion capacity (R = 0.81, p = 0.01 and R = 0.65, p = 0.05). Mean coefficient of variation within patients (CVi) for plasma and urine desmosines was 18.7 to 13.5%, respectively. Change in urinary desmosine levels correlated significantly with change in plasma desmosine levels (R = 0.84, p < 0.01). Mean CVi for fibrinogen fragments in plasma was 20.5% and for JM403 in urine was 27.8%. No correlations were found between fibrinogen fragments or JM403 epitope and desmosines.
We found acceptable variability in our study parameters, indicating the feasibility of their use in an evaluation of biochemical efficacy of alpha-1-antitrypsin augmentation therapy in Pi Z subjects.
PMCID: PMC1159172  PMID: 15927063
alpha-1-antitrypsin; emphysema; JM403; desmosines; biomarkers

Results 1-13 (13)