Emer Kelly

Rapid Lung Function Decline in Smokers Is a Risk Factor for COPD and Is Attenuated by Angiotensin-Converting Enzyme Inhibitor Use

OBJECTIVE Cigarette smoking is the most important risk factor for COPD in the United States. Host factors that influence the rapid rate of FEV1 decline in smokers and how decline rate influences risk for developing COPD are unknown. The aim of this study was to characterize the rate of FEV1 decline in ever smokers, compare the risk of incident COPD between those with rapid decline and others, and determine the effect of selected drugs on rapid decline. METHODS A total of 1,170 eligible ever smokers from the longitudinal Lovelace Smokers Cohort with repeat spirometry tests over a minimum follow-up period of 3 years (mean follow-up, 5.9 years) were examined, including 809 ever smokers without a spirometric abnormality at baseline. Longitudinal absolute decline in postbronchodilator FEV1 from the slope of the spirometric values over all examinations was annualized and classified as rapid (≥30 mL/y), normal (0-29.9 mL/y), or no (>0 mL/y) decline. Logistic regression and Kaplan-Meier survival curves were used for the analysis. RESULTS Approximately 32% of ever smokers exhibited rapid decline. Among ever smokers without a baseline spirometric abnormality, rapid decline was associated with an increased risk for incident COPD (OR, 1.88; P=.003). The use of angiotensin-converting enzyme (ACE) inhibitors at baseline examination was protective against rapid decline, particularly among those with comorbid cardiovascular disease, hypertension, or diabetes (ORs 0.48, 0.48, and 0.12, respectively; P≤.02 for all analyses). CONCLUSIONS Ever smokers with a rapid decline in FEV1 are at higher risk for COPD. Use of ACE inhibitors by smokers may protect against this rapid decline and the progression to COPD.

Protective role for club cell secretory protein-16 (CC16) in the development of COPD.

Club cell secretory protein-16 (CC16) is the major secreted product of airway club cells, but its role in the pathogenesis of chronic obstructive pulmonary disease (COPD) is unclear. We measured CC16 airway expression in humans with and without COPD and CC16 function in a cigarette smoke (CS)-induced COPD murine model. Airway CC16 expression was measured in COPD patients, smokers without COPD and non-smokers. We exposed wildtype (WT) and CC16−/−mice to CS or air for up to 6 months, and measured airway CC16 expression, pulmonary inflammation, alveolar septal cell apoptosis, airspace enlargement, airway mucin 5AC (MUC5AC) expression, small airway remodelling and pulmonary function. Smokers and COPD patients had reduced airway CC16 immunostaining that decreased with increasing COPD severity. Exposing mice to CS reduced airway CC16 expression. CC16−/− mice had greater CS-induced emphysema, airway remodelling, pulmonary inflammation, alveolar cell apoptosis, airway MUC5AC expression, and more compliant lungs than WT mice. These changes were associated with increased nuclear factor-κB (NF-κB) activation in CC16−/− lungs. CS-induced acute pulmonary changes were reversed by adenoviral-mediated over-expression of CC16. CC16 protects lungs from CS-induced injury by reducing lung NF-κB activation. CS-induced airway CC16 deficiency increases CS-induced pulmonary inflammation and injury and likely contributes to the pathogenesis of COPD. Cigarette smoke exposure reduces airway levels of anti-inflammatory CC16 to thereby contribute to the genesis of COPD http://ow.ly/GOMiZ

A novel nonhuman primate model of cigarette smoke-induced airway disease.

Small animal models of chronic obstructive pulmonary disease (COPD) have several limitations for identifying new therapeutic targets and biomarkers for human COPD. These include a pulmonary anatomy that differs from humans, the limited airway pathologies and lymphoid aggregates that develop in smoke-exposed mice, and the challenges associated with serial biological sampling. Thus, we assessed the utility of cigarette smoke (CS)-exposed cynomolgus macaque as a nonhuman primate (NHP) large animal model of COPD. Twenty-eight NHPs were exposed to air or CS 5 days per week for up to 12 weeks. Bronchoalveolar lavage and pulmonary function tests were performed at intervals. After 12 weeks, we measured airway pathologies, pulmonary inflammation, and airspace enlargement. CS-exposed NHPs developed robust mucus metaplasia, submucosal gland hypertrophy and hyperplasia, airway inflammation, peribronchial fibrosis, and increases in bronchial lymphoid aggregates. Although CS-exposed NHPs did not develop emphysema over the study time, they exhibited pathologies that precede emphysema development, including increases in the following: i) matrix metalloproteinase-9 and proinflammatory mediator levels in bronchoalveolar lavage fluid, ii) lung parenchymal leukocyte counts and lymphoid aggregates, iii) lung oxidative stress levels, and iv) alveolar septal cell apoptosis. CS-exposed NHPs can be used as a model of airway disease occurring in COPD patients. Unlike rodents, NHPs can safely undergo longitudinal sampling, which could be useful for assessing novel biomarkers or therapeutics for COPD.

The role of systemic inflammatory biomarkers to predict mortality in chronic obstructive pulmonary disease

The authors discuss the role of inflammatory biomarkers to predict mortality in chronic obstructive pulmonary disease (COPD) in this narrative literature review with expert opinion. The severity of COPD has traditionally been graded using the degree of obstruction as measured by the forced expiratory volume in 1 s because this variable has been predictive of outcomes. However, it is now accepted that COPD is a complex disease with important systemic consequences and that a multidimensional index such as the BMI, obstruction, dyspnea and exercise capacity index is a better predictor of outcome than lung function alone. Because inflammation is thought to play a pivotal role in the genesis of COPD, several serum inflammatory biomarkers have been investigated. Of the ones studied, C-reactive protein, IL-6, pulmonary and activation-regulated chemokine and fibronectin:C-reactive protein ratio have been observed to be independently associated with increased risk of death. When added to known clinical variables such as the BMI, obstruction, dyspnea and exercise capacity index, only IL-6 has been shown to further contribute to mortality prediction. It is likely that the use of an integrative approach combining biomarkers investigated through high-output technology with clinical parameters, combined with new information from the fields of genomics, transcriptomics, proteomics and metabolomics, will improve the authors capacity to predict mortality in COPD.

Disordered breathing during sleep and exercise in idiopathic pulmonary fibrosis and the role of biomarkers

BACKGROUND AND OBJECTIVE Idiopathic pulmonary fibrosis (IPF) patients report fatigue, possibly reflecting sleep disturbance, but little is known about sleep-related changes. We compared ventilation and gas exchange during sleep and exercise in a cohort of IPF patients, and evaluated associations with selected biological markers. METHODS Twenty stable IPF patients (aged 67.9 ± 12.3 [SD]) underwent overnight polysomnography following an acclimatization night. Cardiopulmonary exercise testing was performed and inflammatory markers measured including TNF-α, IL-6, CXCL8, C-C motif ligand 18 (CCL-18) and C-reactive protein (CRP) RESULTS: Nine patients had sleep-disordered breathing (SDB) with an apnea-hypopnea frequency (AHI) ≥ 5/h, but only two had Epworth sleepiness score ≥ 10, thus having an obstructive sleep apnea syndrome. Sleep quality was poor. Transcutaneous carbon dioxide tension (PtcCO2) rose by 2.56 ± 1.59 kPa overnight (P = 0.001), suggesting hypoventilation. Oxygen saturation (SaO2) was lower during sleep than exercise (P < 0.01), and exercise variables correlated with resting pulmonary function. CCL-18 and CRP levels were elevated and correlated with PtcCO2 rise during sleep (P < 0.05). CCL-18 negatively correlated with diffusion capacity of carbon monoxide (DLCO), arterial oxygen (PaO2) and mean arterial carbon dioxide (PaCO2) (P < 0.05) and CRP negatively correlated with DLCO, PaO2, sleep SaO2 and oxygen uptake (VO2) during exercise (P < 0.05). CONCLUSIONS IPF patients desaturate more during sleep than exercise; thus, nocturnal pulse oxymetry could be included in clinical assessment. CCL-18 and CRP levels correlate with physiological markers of fibrosis.

Defining exacerbations in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease is a very common disease often punctuated by intermittent episodes of exacerbation. These exacerbations affect the natural history of the disease, accelerating a decline in lung function. They affect the individual in many ways and affect the health service caring for these patients. The definition of exacerbation varies and lacks clarity. The definitions used most are either symptom based, for example, breathlessness, sputum production and sputum purulence, or event driven, for example, an event causing a patient to seek healthcare input or change to medications. In this article, we discuss the importance of exacerbations, the clinical definitions, clinical trial definitions, physiological and biomarker evidence of exacerbations and the challenges associated with each of these. Application of a practical definition would aid in our clinical management of patients with chronic obstructive pulmonary disease and facilitate developments in future therapeutic advances through clinical trials.

Comparison of arterial and venous blood biomarker levels in chronic obstructive pulmonary disease.

Purpose: The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD). Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9), vascular endothelial growth factor A (VEGF-A) and interleukin 6 (IL-6) in arterial compared with venous blood. Methods: Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. Results were compared using a Student’s paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples. Results: In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6. Conclusions: In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose.

Are respiratory specialist registrars trained to teach

Imparting medical knowledge to undergraduate and graduate learners in respiratory medicine is a multifaceted process. Consultants deliver part of this teaching but registrars also have many teaching interactions with the medical team, both in formal settings and in day-to-day clinical practice. Respiratory SpRs are interested in medical education but rarely observed when teaching and receive little feedback http://ow.ly/Our0m

Pulmonary Zygomycosis in a Non-neutropenic Patient With Myelodysplastic Syndrome on Lenalidomide

Pulmonary zygomycosis is an uncommon infection that occurs mostly in immunocompromised patients. We report the case of a 75-year-old man with myelodysplastic syndrome, treated with lenalidomide for 3 months, who developed respiratory failure and a rapidly progressive left upper lobe consolidation. An extensive workup was unrevealing of the etiology, and the patient expired. A full autopsy was declined, but an in situ post-mortem transbronchial lung biopsy revealed pulmonary zygomycosis. This unique case illustrates the potential risks of lenalidomide therapy in patients with myelodysplastic syndrome and the difficulties in diagnosing pulmonary zygomycosis. To our knowledge this is the first report of a diagnostic in situ post-mortem transbronchial lung biopsy.

Diverse Activities for Proteinases in the Pathogenesis of Chronic Obstructive Pulmonary Disease

COPD remains a major public health problem. It is the fourth leading cause of chronic morbidity and mortality in the United States, and is projected to rank fifth in 2020 in burden of disease caused worldwide, according to a study published by the World Bank/World Health Organization. COPD is a preventable and treatable disease, with some significant extra-pulmonary effects that may contribute to the severity in individual patients. Its pulmonary component is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases. Smoking remains the major risk factor for this disease, but inhalation of other pollutants and genetic factors also play a role.