Janice M. Leung

What is asthma−COPD overlap syndrome? Towards a consensus definition from a round table discussion

Patients with asthma–chronic obstructive pulmonary disease overlap syndrome (ACOS) have been largely excluded from pivotal therapeutic trials and, as a result, its treatment remains poorly defined and lacking firm evidence. To date, there is no universally accepted definition of ACOS, which has made it difficult to understand its epidemiology or pathophysiology. Despite many uncertainties, there is emerging agreement that some of the key features of ACOS include persistent airflow limitation in symptomatic individuals 40 years of age and older, a well-documented history of asthma in childhood or early adulthood and a significant exposure history to cigarette or biomass smoke. In this perspective, we propose a case definition of ACOS that incorporates these key features in a parsimonious algorithm that may enable clinicians to better diagnose patients with ACOS and most importantly enable researchers to design therapeutic and clinical studies to elucidate its epidemiology and pathophysiology and to ascertain its optimal management strategies. We propose that asthma-COPD overlap syndrome be defined based on three major criteria and one minor criterion http://ow.ly/3rOU304aTNm

Absolute Leukocyte Telomere Length in HIV-Infected and Uninfected Individuals: Evidence of Accelerated Cell Senescence in HIV-Associated Chronic Obstructive Pulmonary Disease

Combination antiretroviral therapy (cART) has extended the longevity of human immunodeficiency virus (HIV)-infected individuals. However, this has resulted in greater awareness of age-associated diseases such as chronic obstructive pulmonary disease (COPD). Accelerated cellular senescence may be responsible, but its magnitude as measured by leukocyte telomere length is unknown and its relationship to HIV-associated COPD has not yet been established. We measured absolute telomere length (aTL) in peripheral leukocytes from 231 HIV-infected adults. Comparisons were made to 691 HIV-uninfected individuals from a population-based sample. Subject quartiles of aTL were assessed for relationships with measures of HIV disease severity, airflow obstruction, and emphysema severity on computed tomographic (CT) imaging. Multivariable regression models identified factors associated with shortened aTL. Compared to HIV-uninfected subjects, the mean aTL in HIV-infected patients was markedly shorter by 27 kbp/genome (p<0.001); however, the slopes of aTL vs. age were not different (p=0.469). Patients with longer known durations of HIV infection (p=0.019) and lower nadir CD4 cell counts (p=0.023) had shorter aTL. Shorter aTL were also associated with older age (p=0.026), smoking (p=0.005), reduced forced expiratory volume in one second (p=0.030), and worse CT emphysema severity score (p=0.049). HIV-infected subjects demonstrate advanced cellular aging, yet in a cART-treated cohort, the relationship between aTL and age appears no different from that of HIV-uninfected subjects.

A Systematic Review of Diagnostic Biomarkers of COPD Exacerbation.

The aims of this systematic review were to determine which blood-based molecules have been evaluated as possible biomarkers to diagnose chronic obstructive pulmonary disease (COPD) exacerbations (AECOPD) and to ascertain the quality of these biomarker publications. Patients of interest were those that have been diagnosed with COPD. MEDLINE, EMBASE, and CINAHL databases were searched systematically through February 2015 for publications relating to AECOPD diagnostic biomarkers. We used a modified guideline for the REporting of tumor MARKer Studies (mREMARK) to assess study quality. Additional components of quality included the reporting of findings in a replication cohort and the use of receiver-operating characteristics area-under-the curve statistics in evaluating performance. 59 studies were included, in which the most studied biomarkers were C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). CRP showed consistent elevations in AECOPD compared to control subjects, while IL-6 and TNF-α had variable statistical significance and results. mREMARK scores ranged from 6 to 18 (median score of 13). 12 articles reported ROC analyses and only one study employed a replication cohort to confirm biomarker performance. Studies of AECOPD diagnostic biomarkers remain inconsistent in their reporting, with few studies employing ROC analyses and even fewer demonstrating replication in independent cohorts.

Empowering family physicians to impart proper inhaler teaching to patients with chronic obstructive pulmonary disease and asthma.

BACKGROUND Patients with chronic obstructive pulmonary disease (COPD) and asthma depend on inhalers for management, but critical errors committed during inhaler use can limit drug effectiveness. Outpatient education in inhaler technique remains inconsistent due to limited resources and inadequate provider knowledge. OBJECTIVE To determine whether a simple, two-session inhaler education program can improve physician attitudes toward inhaler teaching in primary care practice. METHODS An inhaler education program with small-group hands-on device training was instituted for family physicians (FP) in British Columbia and Alberta. Sessions were spaced one to three months apart. All critical errors were corrected in the first session. Questionnaires surveying current inhaler teaching practices and attitudes toward inhaler teaching were distributed to physicians before and after the program. RESULTS Forty-one (60%) of a total 68 participating FPs completed both before and after program questionnaires. Before the program, only 20 (49%) reported providing some form of inhaler teaching in their practices, and only four (10%) felt fully competent to teach patients inhaler technique. After the program, 40 (98%) rated their inhaler teaching as good to excellent. Thirty-four (83%) reported providing inhaler teaching in their practices, either by themselves or by an allied health care professional they had personally trained. All stated they could teach inhaler technique within 5 min. Observation of FPs during the second session by certified respiratory educators found that none made critical errors and all had excellent technique. CONCLUSION A physician inhaler education program can improve attitudes toward inhaler teaching and facilitate implementation in clinical practices.

Plasma pro-surfactant protein B and lung function decline in smokers

Plasma pro-surfactant protein B (pro-SFTPB) levels have recently been shown to predict the development of lung cancer in current and ex-smokers, but the ability of pro-SFTPB to predict measures of chronic obstructive pulmonary disease (COPD) severity is unknown. We evaluated the performance characteristics of pro-SFTPB as a biomarker of lung function decline in a population of current and ex-smokers. Plasma pro-SFTPB levels were measured in 2503 current and ex-smokers enrolled in the Pan-Canadian Early Detection of Lung Cancer Study. Linear regression was performed to determine the relationship of pro-SFTPB levels to changes in forced expiratory volume in 1 s (FEV1) over a 2-year period as well as to baseline FEV1 and the burden of emphysema observed in computed tomography (CT) scans. Plasma pro-SFTPB levels were inversely related to both FEV1 % predicted (p=0.024) and FEV1/forced vital capacity (FVC) (p<0.001), and were positively related to the burden of emphysema on CT scans (p<0.001). Higher plasma pro-SFTPB levels were also associated with a more rapid decline in FEV1 at 1 year (p=0.024) and over 2 years of follow-up (p=0.004). Higher plasma pro-SFTPB levels are associated with increased severity of airflow limitation and accelerated decline in lung function. Pro-SFTPB is a promising biomarker for COPD severity and progression. High plasma pro-SFTPB levels are associated with more rapid short-term declines in FEV1 in current and ex-smokers http://ow.ly/E9Gmx

Serum IgG and risk of exacerbations and hospitalizations in chronic obstructive pulmonary disease

Fernando Sergio Leitao Filho, MD, PhD, Seung Won Ra, MD, PhD, Andre Mattman, MD, Robert S. Schellenberg, MD, Nick Fishbane, MSc, Gerard J. Criner, MD, Prescott G. Woodruff, MD, MPH, Stephen C. Lazarus, MD, Richard Albert, MD, John E. Connett, PhD, Meilan K. Han, MD, MSc, Fernando J. Martinez, MD, MSc, Janice M. Leung, MD, S.F. Paul Man, MD, Shawn D. Aaron, MD, Robert M. Reed, MD, Don D. Sin, MD, MPH

Asthma-COPD overlap syndrome: pathogenesis, clinical features, and therapeutic targets

Asthma-COPD overlap syndrome (ACOS) or asthma-COPD overlap captures the subset of patients with airways disease who have features of both asthma and chronic obstructive pulmonary disease (COPD). Although definitions of ACOS vary, it is generally thought to encompass persistent airflow limitation in a patient older than 40 years of age with either a history of asthma or large bronchodilator reversibility. ACOS affects about a quarter of patients with COPD and almost a third of patients who previously had asthma. Compared with their counterparts with asthma or COPD alone, patients with ACOS have significantly worse respiratory symptoms, poorer quality of life, and increased risk of exacerbations and hospital admissions. Whether this condition emerges after gradual shifts in airway remodelling and inflammation in a patient with COPD, as the result of noxious exposures in a patient with asthma, or even as a de novo disease with its own pathology is yet to be determined. Nevertheless, using treatments developed for asthma or COPD that target eosinophilic, neutrophilic, or paucigranulocytic airway inflammation may be a helpful approach to these patients until further clinical trials can be performed.

Responsiveness to Ipratropium Bromide in Male and Female Patients with Mild to Moderate Chronic Obstructive Pulmonary Disease

Introduction Although the prevalence of chronic obstructive pulmonary disease (COPD) is similar between men and women, current evidence used to support bronchodilator therapy has been generated in therapeutic trials that have predominately enrolled male patients. Here, we determined whether there is any significant sex-related differences in FEV1 responses to ipratropium bromide. Methods Data from the Lung Health Study (n = 5887; 37% females) were used to determine changes in FEV1 with ipratropium or placebo in male and female subjects with mild to moderate COPD over 5 years. Lung Expression Quantitative Trait Loci (eQTL) dataset was used to determine whether there were any sex-related differences in gene expression for muscarinic (M2 and M3) receptors in lungs of male and female patients. Results After 4 months, ipratropium therapy increased FEV1 by 6.0% in female and 2.9% in male subjects from baseline values (p = 2.42 × 10− 16). This effect was modified by body mass index (BMI) such that the biggest improvements in FEV1 with ipratropium were observed in thin female subjects (p for BMI ∗ sex interaction = 0.044). The sex-related changes in FEV1 related to ipratropium persisted for 2 years (p = 0.0134). Female compared with male lungs had greater gene expression for M3 relative to M2 receptors (p = 6.86 × 10− 8). Conclusion Ipratropium induces a larger bronchodilator response in female than in male patients and the benefits are particularly notable in non-obese females. Female lungs have greater gene expression for the M3 muscarinic receptor relative to M2 receptors than male lungs. Female patients are thus more likely to benefit from ipratropium than male COPD patients.

Emphysema Distribution and Diffusion Capacity Predict Emphysema Progression in Human Immunodeficiency Virus Infection

Background Chronic obstructive pulmonary disease (COPD) and emphysema are common amongst patients with human immunodeficiency virus (HIV). We sought to determine the clinical factors that are associated with emphysema progression in HIV. Methods 345 HIV-infected patients enrolled in an outpatient HIV metabolic clinic with ≥2 chest computed tomography scans made up the study cohort. Images were qualitatively scored for emphysema based on percentage involvement of the lung. Emphysema progression was defined as any increase in emphysema score over the study period. Univariate analyses of clinical, respiratory, and laboratory data, as well as multivariable logistic regression models, were performed to determine clinical features significantly associated with emphysema progression. Results 17.4% of the cohort were emphysema progressors. Emphysema progression was most strongly associated with having a low baseline diffusion capacity of carbon monoxide (DLCO) and having combination centrilobular and paraseptal emphysema distribution. In adjusted models, the odds ratio (OR) for emphysema progression for every 10% increase in DLCO percent predicted was 0.58 (95% confidence interval [CI] 0.41–0.81). The equivalent OR (95% CI) for centrilobular and paraseptal emphysema distribution was 10.60 (2.93–48.98). Together, these variables had an area under the curve (AUC) statistic of 0.85 for predicting emphysema progression. This was an improvement over the performance of spirometry (forced expiratory volume in 1 second to forced vital capacity ratio), which predicted emphysema progression with an AUC of only 0.65. Conclusion Combined paraseptal and centrilobular emphysema distribution and low DLCO could identify HIV patients who may experience emphysema progression.

COPD Exacerbation Biomarkers Validated Using Multiple Reaction Monitoring Mass Spectrometry.

Background Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) result in considerable morbidity and mortality. However, there are no objective biomarkers to diagnose AECOPD. Methods We used multiple reaction monitoring mass spectrometry to quantify 129 distinct proteins in plasma samples from patients with COPD. This analytical approach was first performed in a biomarker cohort of patients hospitalized with AECOPD (Cohort A, n = 72). Proteins differentially expressed between AECOPD and convalescent states were chosen using a false discovery rate <0.01 and fold change >1.2. Protein selection and classifier building were performed using an elastic net logistic regression model. The performance of the biomarker panel was then tested in two independent AECOPD cohorts (Cohort B, n = 37, and Cohort C, n = 109) using leave-pair-out cross-validation methods. Results Five proteins were identified distinguishing AECOPD and convalescent states in Cohort A. Biomarker scores derived from this model were significantly higher during AECOPD than in the convalescent state in the discovery cohort (p<0.001). The receiver operating characteristic cross-validation area under the curve (CV-AUC) statistic was 0.73 in Cohort A, while in the replication cohorts the CV-AUC was 0.77 for Cohort B and 0.79 for Cohort C. Conclusions A panel of five biomarkers shows promise in distinguishing AECOPD from convalescence and may provide the basis for a clinical blood test to diagnose AECOPD. Further validation in larger cohorts is necessary for future clinical translation.