The relationship between airway structural changes and inflammation is unclear in early cystic fibrosis (CF) lung disease. A study was undertaken to determine changes in airway remodelling in children with CF compared with appropriate disease and healthy controls.
Bronchoalveolar lavage and endobronchial biopsy were performed in a cross‐sectional study of 43 children with CF (aged 0.3–16.8 years), 7 children with primary ciliary dyskinesia (PCD), 26 with chronic respiratory symptoms (CRS) investigated for recurrent infection and/or cough and 7 control children with no lower airway symptoms. Inflammatory cells, cytokines, proteases and matrix constituents were measured in bronchoalveolar lavage fluid (BALF). Reticular basement membrane (RBM) thickness was measured on biopsy specimens using light microscopy.
Increased concentrations of elastin, glycosaminoglycans and collagen were found in BALF from children with CF compared with the CRS group and controls, each correlating positively with age, neutrophil count and proteases (elastase activity and matrix metalloproteinase‐9 (MMP‐9) concentration). There were significant negative correlations between certain of these and pulmonary function (forced expiratory volume in 1 s) in the CF group (elastin: r = −0.45, p<0.05; MMP‐9:TIMP‐1 ratio: r = −0.47, p<0.05). Median RBM thickness was greater in the CF group than in the controls (5.9 μm vs 4.0 μm, p<0.01) and correlated positively with levels of transforming growth factor‐β1 (TGF‐β1; r = 0.53, p = 0.01), although not with other inflammatory markers or pulmonary function.
This study provides evidence for two forms of airway remodelling in children with CF: (1) matrix breakdown, related to inflammation, proteolysis and impaired pulmonary function, and (2) RBM thickening, related to TGF‐β1 concentration but independent of other markers of inflammation.
Impaired lung function is associated with systemic inflammation and is a risk factor for cardiovascular disease in older adults. It is unknown when these associations emerge and to what extent they are mediated by smoking, chronic airways disease, and/or established atherosclerosis. We explored the association between the forced expiratory volume in one second (FEV1) and the systemic inflammatory marker C‐reactive protein (CRP) in young adults.
Associations between spirometric lung function and blood CRP were assessed in a population based birth cohort of approximately 1000 New Zealanders at ages 26 and 32 years. Analyses adjusted for height and sex to account for differences in predicted lung function and excluded pregnant women.
There were significant inverse associations between FEV1 and CRP at both ages. Similar results were found for the forced vital capacity. These associations were similar in men and women and were independent of smoking, asthma, and body mass index.
Reduced lung function is associated with systemic inflammation in young adults. This association is not related to smoking, asthma, or obesity. The reasons for the association are unexplained, but the findings indicate that the association between lower lung function and increased inflammation predates the development of either chronic lung disease or clinically significant atherosclerosis. The association between poor lung function and cardiovascular disease may be mediated by an inflammatory mechanism.
inflammation; C‐reactive protein; spirometry; cohort studies
To ascertain whether therapeutic equivalence exists for the treatment of paediatric community acquired pneumonia by the oral and intravenous (IV) routes.
A multicentre pragmatic randomised controlled non‐blinded equivalence trial was undertaken in eight paediatric centres in England (district general and tertiary hospitals). Equivalence was defined as no more than a 20% difference between treatments of the proportion meeting the primary outcome measure at any time. 246 children who required admission to hospital and had fever, respiratory symptoms or signs and radiologically confirmed pneumonia were included in the study. Exclusion criteria were wheeze, oxygen saturations <85% in air, shock requiring >20 ml/kg fluid resuscitation, immunodeficiency, pleural effusion at presentation requiring drainage, chronic lung condition (excluding asthma), penicillin allergy and age <6 months. The patients were randomised to receive oral amoxicillin for 7 days (n = 126) or IV benzyl penicillin (n = 120). Children in the IV group were changed to oral amoxicillin after a median of six IV doses and received 7 days of antibiotics in total. The predefined primary outcome measure was time for the temperature to be <38°C for 24 continuous hours and oxygen requirement to cease. Secondary outcomes were time in hospital, complications, duration of oxygen requirement and time to resolution of illness.
Oral amoxicillin and IV benzyl penicillin were shown to be equivalent. Median time for temperature to settle was 1.3 days in both groups (p<0.001 for equivalence). Three children in the oral group were changed to IV antibiotics and seven children in the IV group were changed to different IV antibiotics. Median time to complete resolution of symptoms was 9 days in both groups.
Oral amoxicillin is effective for most children admitted to hospital with pneumonia (all but those with the most severe disease who were excluded from this study). Prior to this study, the British Thoracic Society guidelines on childhood pneumonia could not draw on evidence to address this issue. This will spare children and their families the trauma and pain of cannulation, and children will spend less time in hospital.
Lung transplantation is the only treatment modality that provides a survival advantage in pulmonary fibrosis, but many patients deemed suitable will die awaiting lung transplantation. While donor organ shortage undoubtedly contributes to this, late referral to the transplant centre may also play a role. This study investigates factors influencing the chance of patients with pulmonary fibrosis reaching lung transplantation.
A single‐centre retrospective review of patient demographic data, assessment investigations and subsequent clinical outcomes was performed for patients with pulmonary fibrosis assessed for lung transplantation over a 5‐year period.
Between March 1999 and March 2004, 129 patients with pulmonary fibrosis underwent formal transplant assessment. Sixty‐nine were accepted and listed for lung transplantation. Of these, 17 were transplanted, 37 died while waiting, 4 were removed from the list and 11 were still waiting at the conclusion of the study. The median waiting time on the list for those transplanted was 103 days (range 6–904) compared with 125 days (range 2–547) for those who died while on the list (p = 0.65). There was no significant difference in age, spirometry, total lung capacity, gas transfer measures or 6 min walk distance between those who died waiting and those transplanted. However, time from onset of symptoms to transplant assessment was significantly shorter in those who died on the waiting list (median 29 months (range 2–120)) than in those transplanted (median 46 months (range 6–204), p = 0.037).
Patients with pulmonary fibrosis who died awaiting transplantation had similar disease severity at assessment as those who achieved transplantation. However, the interval between symptom onset and transplant referral was significantly shorter in those who died while on the waiting list, suggesting they had more rapidly progressive disease. The rate of disease progression appears to be a more sensitive indicator for transplantation referral than any single physiological measure of disease severity and should act as an important trigger for early transplant referral.
Cannabis smoking constitutes a substantial hazard to the lung
Will we do better in the next 25 years?
Recent studies have indicated long‐term effects on mortality of particulate and sulphur dioxide (SO2) pollution, but uncertainties remain over the size of any effects, potential latency and generalisability.
A small area study was performed across electoral wards in Great Britain of mean annual black smoke (BS) and SO2 concentrations (from 1966) and subsequent all‐cause and cause‐specific mortality using random effect models within a Bayesian framework adjusted for social deprivation and urban/rural classification. Different latencies and changes in associations over time were assessed.
Significant associations were found between BS and SO2 concentrations and mortality. The effects were stronger for respiratory illness than other causes of mortality for the most recent exposure periods (shorter latency times) and most recent mortality period (lower pollutant concentrations). In pooled analysis across four sequential 4 year mortality periods (1982–98), adjusted excess relative risk for respiratory mortality was 3.6% (95% CI 2.6% to 4.5%) per 10 μg/m3 BS and 13.2% (95% CI 11.5% to 14.9%) per 10 ppb SO2, and in the most recent period (1994–8) it was 19.3% (95% CI 5.1% to 35.7%) and 21.7% (95% CI 2.9% to 38.5%), respectively.
These findings add to the evidence that air pollution has long‐term effects on mortality and point to continuing public health risks even at the relatively lower levels of BS and SO2 that now occur. They therefore have importance for policies on public health protection through regulation and control of air pollution.
The finding that patients with asthma feel better after breathing exercises cannot be ignored
The importance of non‐invasive ventilation
Progress in the understanding of COPD
An organisation “fit for purpose”
Chest physicians and respiratory paediatricians must work closely together to prioritise areas of respiratory research
Microsomal epoxide hydrolase (EPHX1) metabolises xenobiotics including polyaromatic hydrocarbons (PAHs). Functional variants at this locus have been associated with respiratory diseases. The effects of EPHX1 variants may depend upon exposures from tobacco smoke and traffic emissions that contain PAHs as well as variants in other enzymes in the PAH metabolic pathway such as glutathione S‐transferase (GST) genes. A study was undertaken to investigate associations of variants in EPHX1, GSTM1, GSTP1 and GSTT1 with asthma and the relationships between asthma, EPHX1 metabolic phenotypes and exposure to sources of PAHs.
Odds ratios (ORs) and 95% confidence intervals (CIs) were computed to estimate the associations of genetic variants and exposures with asthma phenotypes using data from 3124 children from the Children's Health Study.
High EPHX1 activity was associated with an increased risk for lifetime asthma (OR 1.51, 95% CI 1.14 to 1.98) which varied by GSTP1 Ile105Val genotype and by residential proximity to major roads (p for interaction = 0.006 and 0.03, respectively). Among children with GSTP1 105Val/Val genotype, those who had high EPHX1 phenotype had a fourfold (95% CI 1.97 to 8.16) increased risk of lifetime asthma than children with low/intermediate EPHX1 phenotype. Among children living within 75 metres of a major road, those with high EPHX1 activity had a 3.2‐fold (95% CI 1.75 to 6.00) higher lifetime asthma risk than those with low/intermediate activity. The results were similar for current, early persistent and late onset asthma. Children with high EPHX1 phenotype, GSTP1 Val/Val genotype who lived <75 metres from a major road were at the highest asthma risk.
EPHX1 and GSTP1 variants contribute to the occurrence of childhood asthma and increase asthma susceptibility to exposures from major roads.
Roflumilast is a targeted oral once‐daily administered phosphodiesterase 4 (PDE4) inhibitor with clinical efficacy in chronic obstructive pulmonary disease (COPD). Results from in vitro studies with roflumilast indicate that it has anti‐inflammatory properties that may be applicable for the treatment of COPD.
In a crossover study, 38 patients with COPD (mean (SD) age 63.1 (7.0) years, post‐bronchodilator forced expiratory volume in 1 s (FEV1) 61.0 (12.6)% predicted) received 500 μg roflumilast or placebo once daily for 4 weeks. Induced sputum samples were collected before and after 2 and 4 weeks of treatment. Differential and absolute cell counts were determined in whole sputum samples. Markers of inflammation were determined in sputum supernatants and blood. Spirometry was performed weekly.
Roflumilast significantly reduced the absolute number of neutrophils and eosinophils/g sputum compared with placebo by 35.5% (95% CI 15.6% to 50.7%; p = 0.002) and 50.0% (95% CI 26.8% to 65.8%; p<0.001), respectively. The relative proportion of sputum neutrophils and eosinophils was not affected by treatment (p>0.05). Levels of soluble interleukin‐8, neutrophil elastase, eosinophil cationic protein and α2‐macroglobulin in sputum and the release of tumour necrosis factor α from blood cells were significantly reduced by roflumilast compared with placebo treatment (p<0.05 for all). Post‐bronchodilator FEV1 improved significantly during roflumilast compared with placebo treatment with a mean difference between treatments of 68.7 ml (95% CI 12.9 to 124.5; p = 0.018).
PDE4 inhibition by roflumilast treatment for 4 weeks reduced the number of neutrophils and eosinophils, as well as soluble markers of neutrophilic and eosinophilic inflammatory activity in induced sputum samples of patients with COPD. This anti‐inflammatory effect may in part explain the concomitant improvement in post‐bronchodilator FEV1.
The external intercostal muscles are chronically exposed to increased inspiratory loading and to continuous hypoxia‐reoxygenation cycles in patients with obstructive sleep apnoea syndrome (OSAS). It was therefore hypothesised that oxidative stress levels would be increased in these muscles, and that treatment with continuous positive airway pressure (CPAP) would modify the oxidative stress levels and improve muscle dysfunction.
A case‐control study and a case‐case study were conducted on the external intercostal muscles of 12 patients with severe OSAS (before and after 6 months of treatment with CPAP) and 6 control subjects. Reactive carbonyl groups, malondialdehyde (MDA)‐protein and hydroxynonenal (HNE)‐protein adducts, antioxidant enzyme levels, 3‐nitrotyrosine and fibre type proportions were measured using immunoblotting and immunohistochemistry.
Compared with controls, the intercostal muscles of patients with OSAS had higher levels of protein carbonylation (median values 3.06 and 2.45, respectively, p = 0.042), nitration (median values 1.64 and 1.05, respectively, p = 0.019) and proportions of type I fibres (median values 57% and 48%, respectively, p = 0.035) and reduced respiratory muscle endurance (median values 3.2 and 9.5 min, respectively, p = 0.001). Positive correlations were found between MDA‐protein and HNE‐protein adducts (r = 0.641, p = 0.02 and r = 0.594, p = 0.05, respectively) and 3‐nitrotyrosine (r = 0.625, p = 0.03) and the apnoea‐hypopnoea index (AHI) in all the patients with OSAS. Although treatment with CPAP significantly improved the AHI and oxygen desaturation, muscle oxidative stress levels and respiratory muscle endurance were not affected.
This study suggests that inspiratory muscle performance is not completely restored after long‐term treatment with CPAP.
An integrated breathing and relaxation technique known as the Papworth method has been implemented by physiotherapists since the 1960s for patients with asthma and dysfunctional breathing, but no controlled trials have been reported. This study evaluated the effectiveness of the Papworth method in a randomised controlled trial.
Eighty‐five patients (36 men) were individually randomised to the control group (n = 46) or to the intervention group receiving five sessions of treatment by the Papworth method (n = 39). Both groups received usual medical care. Assessments were undertaken at baseline, post‐treatment (6 months after baseline) and at 12 months. The primary outcome measure was the St George's Respiratory Symptoms Questionnaire (SGRQ). Secondary outcome measures included the Hospital Anxiety and Depression Scale (HADS), the Nijmegen dysfunctional breathing questionnaire and objective measures of respiratory function.
Post‐treatment and 12 month data were available for 78 and 72 patients, respectively. At the post‐treatment assessment the mean (SD) score on the SGRQ Symptom subscale was 21.8 (18.1) in the intervention group and 32.8 (20.1) in the control group (p = 0.001 for the difference). At the 12 month follow‐up the corresponding figures were 24.9 (17.9) and 33.5 (15.9) (p = 0.007 for the difference). SGRQ Total scores and HADS and Nijmegen scores were similarly significantly lower in the intervention group than in the control group. The groups did not differ significantly following the treatment on objective measures of respiratory function except for relaxed breathing rate.
The Papworth method appears to ameliorate respiratory symptoms, dysfunctional breathing and adverse mood compared with usual care. Further controlled trials are warranted to confirm this finding, assess the effect in other patient groups and determine whether there is some effect on objective measures of respiratory function.
Non‐eosinophilic asthma is a potentially important clinicopathological phenotype since there is evidence that it responds poorly to inhaled corticosteroid therapy. However, little is known about the underlying airway immunopathology and there are no data from placebo‐controlled studies examining the effect of inhaled corticosteroids.
Airway immunopathology was investigated using induced sputum, bronchial biopsies, bronchial wash and bronchoalveolar lavage in 12 patients with symptomatic eosinophilic asthma, 11 patients with non‐eosinophilic asthma and 10 healthy controls. The patients with non‐eosinophilic asthma and 6 different patients with eosinophilic asthma entered a randomised, double‐blind, placebo‐controlled crossover study in which the effects of inhaled mometasone 400 μg once daily for 8 weeks on airway responsiveness and asthma quality of life were investigated.
Patients with non‐eosinophilic asthma had absence of eosinophils in the mucosa (median 4.4 cells/mm2 vs 23 cells/mm2 in eosinophilic asthma and 0 cells/mm2 in normal controls; p = 0.03) and normal subepithelial layer thickness (5.8 μm vs 10.3 μm in eosinophilic asthma and 5.1 μm in controls, p = 0.002). Non‐eosinophilic and eosinophilic asthma groups had increased mast cell numbers in the airway smooth muscle compared with normal controls (9 vs 8 vs 0 cells/mm2, p = 0.016). Compared with placebo, 8 weeks of treatment with inhaled mometasone led to less improvement in methacholine PC20 (0.5 vs 5.5 doubling concentrations, 95% CI of difference 1.1 to 9.1; p = 0.018) and asthma quality of life (0.2 vs 1.0 points, 95% CI of difference 0.27 to 1.43; p = 0.008).
Non‐eosinophilic asthma represents a pathologically distinct disease phenotype which is characterised by the absence of airway eosinophilia, normal subepithelial layer thickness and a poor short‐term response to treatment with inhaled corticosteroids.
Cannabis is the most widely used illegal drug worldwide. Long‐term use of cannabis is known to cause chronic bronchitis and airflow obstruction, but the prevalence of macroscopic emphysema, the dose‐response relationship and the dose equivalence of cannabis with tobacco has not been determined.
A convenience sample of adults from the Greater Wellington region was recruited into four smoking groups: cannabis only, tobacco only, combined cannabis and tobacco and non‐smokers of either substance. Their respiratory status was assessed using high‐resolution CT (HRCT) scanning, pulmonary function tests and a respiratory and smoking questionnaire. Associations between respiratory status and cannabis use were examined by analysis of covariance and logistic regression.
339 subjects were recruited into the four groups. A dose‐response relationship was found between cannabis smoking and reduced forced expiratory volume in 1 s to forced vital capacity ratio and specific airways conductance, and increased total lung capacity. For measures of airflow obstruction, one cannabis joint had a similar effect to 2.5–5 tobacco cigarettes. Cannabis smoking was associated with decreased lung density on HRCT scans. Macroscopic emphysema was detected in 1/75 (1.3%), 15/92 (16.3%), 17/91 (18.9%) and 0/81 subjects in the cannabis only, combined cannabis and tobacco, tobacco alone and non‐smoking groups, respectively.
Smoking cannabis was associated with a dose‐related impairment of large airways function resulting in airflow obstruction and hyperinflation. In contrast, cannabis smoking was seldom associated with macroscopic emphysema. The 1:2.5–5 dose equivalence between cannabis joints and tobacco cigarettes for adverse effects on lung function is of major public health significance.