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1.  Empowering family physicians to impart proper inhaler teaching to patients with chronic obstructive pulmonary disease and asthma 
Treatment of many chronic diseases involves oral drug ingestion or infusion. Chronic obstructive pulmonary disease and asthma, however, generally rely on inhaler devices to deliver medications and, are therefore, prone to critical errors in how they are used, which reduces their effectiveness. Given the significant economic and health burdens of chronic obstructive pulmonary disease and asthma in Canada, improved inhaler technique would lead to reduced number of emergency room visits and hospitalizations, and better clinical outcomes and disease control. This study aimed to determine whether a simple inhaler education program could influence physicians’ attitudes toward inhaler teaching in primary care practice, which is currently lacking.
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.
To determine whether a simple, two-session inhaler education program can improve physician attitudes toward inhaler teaching in primary care practice.
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.
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.
A physician inhaler education program can improve attitudes toward inhaler teaching and facilitate implementation in clinical practices.
PMCID: PMC4596648  PMID: 26436910
Asthma; COPD; Inhaler devices; Medical education; Primary care
2.  Pro–Surfactant Protein B As a Biomarker for Lung Cancer Prediction 
Journal of Clinical Oncology  2013;31(36):4536-4543.
Preliminary studies have identified pro–surfactant protein B (pro-SFTPB) to be a promising blood biomarker for non–small-cell lung cancer. We conducted a study to determine the independent predictive potential of pro-SFTPB in identifying individuals who are subsequently diagnosed with lung cancer.
Patients and Methods
Pro-SFTPB levels were measured in 2,485 individuals, who enrolled onto the Pan-Canadian Early Detection of Lung Cancer Study by using plasma sample collected at the baseline visit. Multivariable logistic regression models were used to evaluate the predictive ability of pro-SFTPB in addition to known lung cancer risk factors. Calibration and discrimination were evaluated, the latter by an area under the receiver operating characteristic curve (AUC). External validation was performed with samples collected in the Carotene and Retinol Efficacy Trial (CARET) participants using a case-control study design.
Adjusted for age, sex, body mass index, personal history of cancer, family history of lung cancer, forced expiratory volume in one second percent predicted, average number of cigarettes smoked per day, and smoking duration, pro-SFTPB (log transformed) had an odds ratio of 2.220 (95% CI, 1.727 to 2.853; P < .001). The AUCs of the full model with and without pro-SFTPB were 0.741 (95% CI, 0.696 to 0.783) and 0.669 (95% CI, 0.620 to 0.717; difference in AUC P < .001). In the CARET Study, the use of pro-SFPTB yielded an AUC of 0.683 (95% CI, 0.604 to 0.761).
Pro-SFTPB in plasma is an independent predictor of lung cancer and may be a valuable addition to existing lung cancer risk prediction models.
PMCID: PMC3871515  PMID: 24248694
3.  Impact of individualized care on readmissions after a hospitalization for acute exacerbation of COPD 
Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) increase COPD morbidity and mortality and impose a great burden on health care systems. Early readmission following a hospitalization for AECOPD remains an important clinical problem. We examined how individualized comprehensive care influences readmissions following an index hospital admission for AECOPD.
We retrospectively reviewed data of patients admitted for AECOPD to two inner-city teaching hospitals to determine the impact of a comprehensive and individualized care management strategy on readmissions for AECOPD. The control group consisted of 271 patients whose index AECOPD occurred the year before the comprehensive program, and the experimental group consisted of 191 patients who received the comprehensive care. The primary outcome measure was the total number of readmissions in 30- and 90-day postindex hospitalizations. Secondary outcome measures included the length of time between the index admission and first readmission and all-cause mortality.
The two groups were similar in terms of age, sex, forced expiratory volume in 1 second, body mass index (BMI), pack-years, and the number and types of comorbidities. Comprehensive care significantly reduced 90-day readmission rates in females (P=0.0205, corrected for age, BMI, number of comorbidities, substance abuse, and mental illness) but not in males or in the whole group (P>0.05). The average times between index admission and first readmission were not different between the two groups. Post hoc multivariate analysis showed that substance abuse (P<0.01) increased 30- and 90-day readmissions (corrected for age, sex, BMI, number of comorbidities, and mental illness). The 90-day all-cause in-hospital mortality rates were significantly less in the care package group (2.67% versus 7.97%, P=0.0268).
Comprehensive individualized care for subjects admitted to hospital for AECOPD did not reduce 30- and 90-day readmission rates but did reduce 90-day total mortality. Interestingly, it reduced 90-day readmission rate in females. We speculate that an individualized care package could impact COPD morbidity and mortality after an acute exacerbation.
PMCID: PMC4708191  PMID: 26792986
readmissions; care package; substance abuse; female; mortality
4.  Sixteen new lung function signals identified through 1000 Genomes Project reference panel imputation 
Artigas, María Soler | Wain, Louise V. | Miller, Suzanne | Kheirallah, Abdul Kader | Huffman, Jennifer E. | Ntalla, Ioanna | Shrine, Nick | Obeidat, Ma'en | Trochet, Holly | McArdle, Wendy L. | Alves, Alexessander Couto | Hui, Jennie | Zhao, Jing Hua | Joshi, Peter K. | Teumer, Alexander | Albrecht, Eva | Imboden, Medea | Rawal, Rajesh | Lopez, Lorna M. | Marten, Jonathan | Enroth, Stefan | Surakka, Ida | Polasek, Ozren | Lyytikäinen, Leo-Pekka | Granell, Raquel | Hysi, Pirro G. | Flexeder, Claudia | Mahajan, Anubha | Beilby, John | Bossé, Yohan | Brandsma, Corry-Anke | Campbell, Harry | Gieger, Christian | Gläser, Sven | González, Juan R. | Grallert, Harald | Hammond, Chris J. | Harris, Sarah E. | Hartikainen, Anna-Liisa | Heliövaara, Markku | Henderson, John | Hocking, Lynne | Horikoshi, Momoko | Hutri-Kähönen, Nina | Ingelsson, Erik | Johansson, Åsa | Kemp, John P. | Kolcic, Ivana | Kumar, Ashish | Lind, Lars | Melén, Erik | Musk, Arthur W. | Navarro, Pau | Nickle, David C. | Padmanabhan, Sandosh | Raitakari, Olli T. | Ried, Janina S. | Ripatti, Samuli | Schulz, Holger | Scott, Robert A. | Sin, Don D. | Starr, John M. | Viñuela, Ana | Völzke, Henry | Wild, Sarah H. | Wright, Alan F. | Zemunik, Tatijana | Jarvis, Deborah L. | Spector, Tim D. | Evans, David M. | Lehtimäki, Terho | Vitart, Veronique | Kähönen, Mika | Gyllensten, Ulf | Rudan, Igor | Deary, Ian J. | Karrasch, Stefan | Probst-Hensch, Nicole M. | Heinrich, Joachim | Stubbe, Beate | Wilson, James F. | Wareham, Nicholas J. | James, Alan L. | Morris, Andrew P. | Jarvelin, Marjo-Riitta | Hayward, Caroline | Sayers, Ian | Strachan, David P. | Hall, Ian P. | Tobin, Martin D.
Nature Communications  2015;6:8658.
Lung function measures are used in the diagnosis of chronic obstructive pulmonary disease. In 38,199 European ancestry individuals, we studied genome-wide association of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC with 1000 Genomes Project (phase 1)-imputed genotypes and followed up top associations in 54,550 Europeans. We identify 14 novel loci (P<5 × 10−8) in or near ENSA, RNU5F-1, KCNS3, AK097794, ASTN2, LHX3, CCDC91, TBX3, TRIP11, RIN3, TEKT5, LTBP4, MN1 and AP1S2, and two novel signals at known loci NPNT and GPR126, providing a basis for new understanding of the genetic determinants of these traits and pulmonary diseases in which they are altered.
Genetic and environmental factors impact on lung function, important in the diagnosis of pulmonary diseases. Here the authors use imputation of genotypes to the 1000 Genomes Project reference panel to identify novel, low frequency variants associated with lung function.
PMCID: PMC4686825  PMID: 26635082
5.  Association of blood eosinophils and plasma periostin with FEV1 response after 3-month inhaled corticosteroid and long-acting beta2-agonist treatment in stable COPD patients 
COPD patients with increased airway eosinophilic inflammation show a favorable response to inhaled corticosteroids (ICS) in combination with a long-acting bronchodilator. Recent studies have demonstrated a significant correlation of sputum eosinophilia with blood eosinophils and periostin. We investigated whether high blood eosinophils and plasma periostin were associated with an improvement in forced expiratory volume in 1 second (FEV1) after 3-month treatment with ICS/long-acting beta2-agonist (LABA) in stable COPD patients.
Patients and methods
Blood eosinophils and plasma periostin levels were measured in 130 stable COPD subjects selected from the Korean Obstructive Lung Disease cohort. Subjects began a 3-month ICS/LABA treatment after washout period.
High blood eosinophils (>260/µL, adjusted odds ratio =3.52, P=0.009) and high plasma periostin (>23 ng/mL, adjusted odds ratio =3.52, P=0.013) were significantly associated with FEV1 responders (>12% and 200 mL increase in FEV1 from baseline after treatment). Moreover, the addition of high blood eosinophils to age, baseline positive bronchodilator response, and FEV1 <50% of the predicted value significantly increased the area under the curve for prediction of FEV1 responders (from 0.700 to 0.771; P=0.045).
High blood eosinophils and high plasma periostin were associated with improved lung function after 3-month ICS/LABA treatment. In particular, high blood eosinophils, in combination with age and baseline lung function parameters, might be a possible biomarker for identification of COPD patients with favorable FEV1 improvement in response to ICS/LABA treatment.
PMCID: PMC4694663  PMID: 26730185
eosinophils; periostin; COPD
6.  Susceptibility loci for lung cancer are associated with mRNA levels of nearby genes in the lung 
Carcinogenesis  2014;35(12):2653-2659.
This study extends the functional meaning of lung cancer susceptibility loci to gene expression in the lung and suggests that the risk alleles on 15q25 and 6p21 mediate their effect by regulating the expression levels of CHRNA5 and APOM, respectively.
Recent studies identified three genetic loci reproducibly associated with lung cancer in populations of European ancestry, namely 15q25, 5p15 and 6p21. The goals of this study are first to confirm whether these loci are associated with lung cancer in a French Canadian population and second to identify disease-associated single nucleotide polymorphisms (SNPs) influencing messenger RNA (mRNA) expression levels of genes in the lung, that is expression quantitative trait loci (eQTLs). SNPs were genotyped in 420 patients undergoing lung cancer surgery and compared with 3151 controls of European ancestry. Genome-wide gene expression levels in non-tumor lung tissues of the same 420 patients were also measured to identify eQTLs. Significant eQTLs were then followed-up in two replication sets (n = 339 and 363). SNPs found in the three susceptibility loci were associated with lung cancer in the French Canadian population. Strong eQTLs were found on chromosome 15q25 with the expression levels of CHRNA5 (P = 2.23 × 10− 22 with rs12907966). The CHRNA5-rs12907966 eQTL was convincingly validated in the two replication sets (P = 3.46 × 10− 16 and 2.01 × 10− 15). On 6p21, a trend was observed for rs3131379 to be associated with the expression of APOM (P = 3.58 × 10− 4) and validated in the replication sets (P = 1.11 × 10− 8 and 6.84 × 10− 4). On 5p15, no significant eQTLs were found. This study confirmed that chromosomes 15q25, 5p15 and 6p21 harbored susceptibility loci for lung cancer in French Canadians. Most importantly, this study suggests that the risk alleles at 15q25 and 6p21 may mediate their effect by regulating the mRNA expression levels of CHRNA5 and APOM in the lung.
PMCID: PMC4247514  PMID: 25187487
7.  Impact of Statins on Gene Expression in Human Lung Tissues 
PLoS ONE  2015;10(11):e0142037.
Statins are 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors that alter the synthesis of cholesterol. Some studies have shown a significant association of statins with improved respiratory health outcomes of patients with asthma, chronic obstructive pulmonary disease and lung cancer. Here we hypothesize that statins impact gene expression in human lungs and may reveal the pleiotropic effects of statins that are taking place directly in lung tissues. Human lung tissues were obtained from patients who underwent lung resection or transplantation. Gene expression was measured on a custom Affymetrix array in a discovery cohort (n = 408) and two replication sets (n = 341 and 282). Gene expression was evaluated by linear regression between statin users and non-users, adjusting for age, gender, smoking status, and other covariables. The results of each cohort were combined in a meta-analysis and biological pathways were studied using Gene Set Enrichment Analysis. The discovery set included 141 statin users. The lung mRNA expression levels of eighteen and three genes were up-regulated and down-regulated in statin users (FDR < 0.05), respectively. Twelve of the up-regulated genes were replicated in the first replication set, but none in the second (p-value < 0.05). Combining the discovery and replication sets into a meta-analysis improved the significance of the 12 up-regulated genes, which includes genes encoding enzymes and membrane proteins involved in cholesterol biosynthesis. Canonical biological pathways altered by statins in the lung include cholesterol, steroid, and terpenoid backbone biosynthesis. No genes encoding inflammatory, proteases, pro-fibrotic or growth factors were altered by statins, suggesting that the direct effect of statin in the lung do not go beyond its antilipidemic action. Although more studies are needed with specific lung cell types and different classes and doses of statins, the improved health outcomes and survival observed in statin users with chronic lung diseases do not seem to be mediated through direct regulation of gene expression in the lung.
PMCID: PMC4633125  PMID: 26535575
8.  Club Cell Protein 16 and Disease Progression in Chronic Obstructive Pulmonary Disease 
Rationale: Club (Clara) cell protein 16 (CC-16) is a protein that is synthesized predominantly in the lungs and is detectable in serum. Its expression decreases with lung injury and smoking, and is thus a marker of bronchial cell dysfunction.
Objectives: To evaluate the possibility of using serum CC-16 as a biomarker for disease progression in chronic obstructive pulmonary disease (COPD).
Methods: We measured serum CC-16 levels from 4,724 subjects with mild-to-moderate airflow limitation in the Lung Health Study. Using a linear regression model, we determined the relationship of serum CC-16 concentrations to decline in lung function over 9 years. In addition, to determine whether CC-16 plays a major role in the pathogenesis of mild COPD, we exposed CC-16–deficient (−/−) mice to 6 months of cigarette smoke.
Measurements and Main Results: Reduced serum concentrations of CC-16 were associated with accelerated decline in FEV1 over 9 years (P < 0.0001), and this association persisted after adjustments for age, sex, race, smoking status, airway reactivity, body mass index, and baseline FEV1 (P = 0.0002). However, CC-16−/− mice did not demonstrate an enhanced risk of emphysema or small airway remodeling in response to cigarette smoke.
Conclusions: Serum CC-16 is associated with disease progression, and may assist in the identification of “rapid progressors.” However, the absence of CC-16 does not appear to modify the risk of cigarette-related COPD in mice.
PMCID: PMC3917377  PMID: 24245748
biomarker; chronic obstructive pulmonary disease; disease progression; smoking
9.  The Effect of Statins on Blood Gene Expression in COPD 
PLoS ONE  2015;10(10):e0140022.
COPD is currently the fourth leading cause of death worldwide. Statins are lipid lowering agents with documented cardiovascular benefits. Observational studies have shown that statins may have a beneficial role in COPD. The impact of statins on blood gene expression from COPD patients is largely unknown.
Identify blood gene signature associated with statin use in COPD patients, and the pathways underpinning this signature that could explain any potential benefits in COPD.
Whole blood gene expression was measured on 168 statin users and 451 non-users from the ECLIPSE study using the Affymetrix Human Gene 1.1 ST microarray chips. Factor Analysis for Robust Microarray Summarization (FARMS) was used to process the expression data. Differential gene expression analysis was undertaken using the Linear Models for Microarray data (Limma) package adjusting for propensity score and surrogate variables. Similarity of the expression signal with published gene expression profiles was performed in ProfileChaser.
25 genes were differentially expressed between statin users and non-users at an FDR of 10%, including LDLR, CXCR2, SC4MOL, FAM108A1, IFI35, FRYL, ABCG1, MYLIP, and DHCR24. The 25 genes were significantly enriched in cholesterol homeostasis and metabolism pathways. The resulting gene signature showed correlation with Huntington’s disease, Parkinson’s disease and acute myeloid leukemia gene signatures.
The blood gene signature of statins’ use in COPD patients was enriched in cholesterol homeostasis pathways. Further studies are needed to delineate the role of these pathways in lung biology.
PMCID: PMC4604084  PMID: 26462087
10.  Associations of interleukin-1 gene cluster polymorphisms with C-reactive protein concentration and lung function decline in smoking-induced chronic obstructive pulmonary disease 
Objective: We reported association of haplotypes formed by IL-1b (IL1B)-511C/T (rs16944) and a variable number of tandem repeats (rs2234663) in intron 3 of IL-1 receptor antagonist (IL1RN) with rate of lung function decline in smoking-induced COPD. The aim of current study was to further investigate this association. Methods: We genotyped an additional 19 polymorphisms in IL1 cluster (including IL1A, IL1B and IL1RN) in non-Hispanic whites who had the fastest (n = 268) and the slowest (n = 292) decline of FEV1% predicted in the same study. We also analyzed the association of all 21 polymorphisms with serum CRP levels. Results: None of 21 polymorphisms showed significant association with rate of decline of lung function or CRP levels after adjusting for multiple comparisons. Before adjusting for multiple comparisons, only IL1RN_19327 (rs315949) showed significant association with lung function decline (P = 0.03, additive model). The frequencies of genotypes containing the IL1RN_19327A allele were 71.9% and 62.2%, respectively in the fast and slow decline groups (P = 0.02, odds ratio = 1.6, 95% confidence interval = 1.1-2.3); the IL1B_5200 (rs1143633) and rs2234663 in IL1RN were associated with serum CRP levels (P=0.04 and 0.03, respectively). Conclusions: No single marker was significantly associated with either rate of lung function decline or serum CRP levels.
PMCID: PMC4680456  PMID: 26722511
Chronic obstructive pulmonary disease (COPD); forced expiratory volume in one second (FEV1); genetic polymorphism; IL1 gene cluster; lung function decline; C-reactive protein
11.  Immunoglobulin G4-related lung disease: A disease with many different faces 
Immunoglobulin (Ig) G4-related lung disease is a fibroinflammatory entity that presents in protean ways. Diagnostically, IgG4-related lung disease requires a high clinical index of suspicion complemented by elevated serum IgG4 levels and/or biopsy that shows the characteristic pathological features. The disease is almost always responsive to systemic corticosteroids. However, relapse is common following their discontinuation. The authors present three cases to highlight the diverse clinical features, and to illustrate the diagnostic and therapeutic approaches to this disease.
PMCID: PMC3810041  PMID: 24093112
Corticosteroids; IgG4-related lung disease; Immunoglobulins
12.  Informed Genome-Wide Association Analysis With Family History As a Secondary Phenotype Identifies Novel Loci of Lung Cancer 
Genetic epidemiology  2015;39(3):197-206.
Lung cancer is the leading cause of cancer death worldwide. Although several genetic variants associated with lung cancer have been identified in the past, stringent selection criteria of genome-wide association studies (GWAS) can lead to missed variants. The objective of this study was to uncover missed variants by using the known association between lung cancer and first-degree family history of lung cancer to enrich the variant prioritization for lung cancer susceptibility regions. In this two-stage GWAS study, we first selected a list of variants associated with both lung cancer and family history of lung cancer in four GWAS (3,953 cases, 4,730 controls), then replicated our findings for 30 variants in a meta-analysis of four additional studies (7,510 cases, 7,476 controls). The top ranked genetic variant rs12415204 in chr10q23.33 encoding FFAR4 in the Discovery set was validated in the Replication set with an overall OR of 1.09 (95% CI = 1.04, 1.14, P = 1.63 × 10−4). When combining the two stages of the study, the strongest association was found in rs1158970 at Ch4p15.2 encoding KCNIP4 with an OR of 0.89 (95% CI = 0.85, 0.94, P = 9.64 × 10−6). We performed a stratified analysis of rs12415204 and rs1158970 across all eight studies by age, gender, smoking status, and histology, and found consistent results across strata. Four of the 30 replicated variants act as expression quantitative trait loci (eQTL) sites in 1,111 nontumor lung tissues and meet the genome-wide 10% FDR threshold.
PMCID: PMC4554719  PMID: 25644374
lung cancer; family history; secondary phenotype; genetic susceptibility; genome-wide association studies; eQTL
13.  Bacterial microbiome of lungs in COPD 
Chronic obstructive pulmonary disease (COPD) is currently the third leading cause of death in the world. Although smoking is the main risk factor for this disease, only a minority of smokers develop COPD. Why this happens is largely unknown. Recent discoveries by the human microbiome project have shed new light on the importance and richness of the bacterial microbiota at different body sites in human beings. The microbiota plays a particularly important role in the development and functional integrity of the immune system. Shifts or perturbations in the microbiota can lead to disease. COPD is in part mediated by dysregulated immune responses to cigarette smoke and other environmental insults. Although traditionally the lung has been viewed as a sterile organ, by using highly sensitive genomic techniques, recent reports have identified diverse bacterial communities in the human lung that may change in COPD. This review summarizes the current knowledge concerning the lung microbiota in COPD and its potential implications for pathogenesis of the disease.
PMCID: PMC3937108  PMID: 24591822
chronic obstructive pulmonary disease; bacterial microbiome; lungs
14.  DNA Methylation Is Globally Disrupted and Associated with Expression Changes in Chronic Obstructive Pulmonary Disease Small Airways 
DNA methylation is an epigenetic modification that is highly disrupted in response to cigarette smoke and involved in a wide spectrum of malignant and nonmalignant diseases, but surprisingly not previously assessed in small airways of patients with chronic obstructive pulmonary disease (COPD). Small airways are the primary sites of airflow obstruction in COPD. We sought to determine whether DNA methylation patterns are disrupted in small airway epithelia of patients with COPD, and evaluate whether changes in gene expression are associated with these disruptions. Genome-wide methylation and gene expression analysis were performed on small airway epithelial DNA and RNA obtained from the same patient during bronchoscopy, using Illumina’s Infinium HM27 and Affymetrix’s Genechip Human Gene 1.0 ST arrays. To control for known effects of cigarette smoking on DNA methylation, methylation and gene expression profiles were compared between former smokers with and without COPD matched for age, pack-years, and years of smoking cessation. Our results indicate that aberrant DNA methylation is (1) a genome-wide phenomenon in small airways of patients with COPD, and (2) associated with altered expression of genes and pathways important to COPD, such as the NF-E2–related factor 2 oxidative response pathway. DNA methylation is likely an important mechanism contributing to modulation of genes important to COPD pathology. Because these methylation events may underlie disease-specific gene expression changes, their characterization is a critical first step toward the development of epigenetic markers and an opportunity for developing novel epigenetic therapeutic interventions for COPD.
PMCID: PMC4068945  PMID: 24298892
chronic obstructive pulmonary disease; small airways; epigenetic regulation; DNA methylation; integrative omics
15.  Absolute Leukocyte Telomere Length in HIV-Infected and Uninfected Individuals: Evidence of Accelerated Cell Senescence in HIV-Associated Chronic Obstructive Pulmonary Disease 
PLoS ONE  2015;10(4):e0124426.
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.
PMCID: PMC4401786  PMID: 25885433
17.  Bronchodilator Responsiveness and Reported Respiratory Symptoms in an Adult Population 
PLoS ONE  2013;8(3):e58932.
The relationship between patient-reported symptoms and objective measures of lung function is poorly understood.
To determine the association between responsiveness to bronchodilator and respiratory symptoms in random population samples.
4669 people aged 40 years and older from 8 sites in Canada completed interviewer-administered respiratory questionnaires and performed spirometry before and after administration of 200 ug of inhaled salbutamol. The effect of anthropometric variables, smoking exposure and doctor-diagnosed asthma (DDA) on bronchodilator responsiveness in forced expiratory volume in 1 second (FEV1) and in forced vital capacity (FVC) were evaluated. Multiple logistic regression was used to test for association between quintiles of increasing changes in FEV1 and in FVC after bronchodilator and several respiratory symptoms.
Determinants of bronchodilator change in FEV1 and FVC included age, DDA, smoking, respiratory drug use and female gender [p<0.005 to p<0.0001 ]. In subjects without doctor-diagnosed asthma or COPD, bronchodilator response in FEV1 was associated with wheezing [p for trend<0.0001], while bronchodilator response for FVC was associated with breathlessness. [p for trend <0.0001].
Bronchodilator responsiveness in FEV1 or FVC are associated with different respiratory symptoms in the community. Both flow and volume bronchodilator responses are useful parameters which together can be predictive of both wheezing and breathlessness in the general population.
PMCID: PMC3598856  PMID: 23554960
18.  Genes related to emphysema are enriched for ubiquitination pathways 
BMC Pulmonary Medicine  2014;14:187.
Increased small airway resistance and decreased lung elasticity contribute to the airflow limitation in chronic obstructive pulmonary disease (COPD). The lesion that corresponds to loss of lung elasticity is emphysema; the small airway obstruction is due to inflammatory narrowing and obliteration. Despite their convergence in altered physiology, different mechanisms contribute to these processes. The relationships between gene expression and these specific phenotypes may be more revealing than comparison with lung function.
We measured the ratio of alveolar surface area to lung volume (SA/V) in lung tissue from 43 smokers. Two samples from 21 subjects, in which SA/V differed by >49 cm2/mL were profiled to select genes whose expression correlated with SA/V. Significant genes were tested for replication in the 22 remaining subjects.
The level of expression of 181 transcripts was related to SA/V ( p < 0.05). When these genes were tested in the 22 remaining subjects as a replication, thirty of the 181 genes remained significantly associated with SA/V (P < 0.05) and the direction of association was the same in 164/181. Pathway and network analysis revealed enrichment of genes involved in protein ubiquitination, and western blotting showed altered expression of genes involved in protein ubiquitination in obstructed individuals.
This study implicates modified protein ubiquitination and degradation as a potentially important pathway in the pathogenesis of emphysema.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2466-14-187) contains supplementary material, which is available to authorized users.
PMCID: PMC4280711  PMID: 25432663
Pulmonary emphysema; Surface area to lung volume ratio; Gene expression; Transcriptional analysis; mRNA; Cigarette smoking; Protein ubquitination
19.  Effects of inhaled corticosteroids on airway inflammation in chronic obstructive pulmonary disease: a systematic review and meta-analysis 
Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation in the small airways. The effect of inhaled corticosteroids (ICS) on lung inflammation in COPD remains uncertain. We sought to determine the effects of ICS on inflammatory indices in bronchial biopsies and bronchoalveolar lavage fluid of patients with COPD.
We searched Medline, Embase, Cinahl, and the Cochrane database for randomized, controlled clinical trials that used bronchial biopsies and bronchoalveolar lavage to evaluate the effects of ICS in stable COPD. For each chosen study, we calculated the mean differences in the concentrations of inflammatory cells before and after treatment in both intervention and control groups. These values were then converted into standardized mean differences (SMD) to accommodate the differences in patient selection, clinical treatment, and biochemical procedures that were employed across the original studies. If significant heterogeneity was present (P < 0.1), then a random effects model was used to pool the original data; otherwise, a fixed effects model was used.
We identified eight original studies that met the inclusion criteria. Four studies used bronchial biopsies (n =102 participants) and showed that ICS were effective in reducing CD4 and CD8 cell counts (SMD, −0.52 units and −0.66 units, 95% confidence interval). The five studies used bronchoalveolar lavage fluid (n =309), which together showed that ICS reduced neutrophil and lymphocyte counts (SMD, −0.64 units and −0.64 units, 95% confidence interval). ICS on the other hand significantly increased macrophage counts (SMD, 0.68 units, 95% confidence interval) in bronchoalveolar lavage fluid.
ICS has important immunomodulatory effects in airways with COPD that may explain its beneficial effect on exacerbations and enhanced risk of pneumonia.
PMCID: PMC3459653  PMID: 23055709
chronic obstructive pulmonary disease; bronchial biopsies; bronchoalveolar lavage; inhaled corticosteroids; inflammation; inflammatory markers; meta-analysis
20.  Burden of subclinical heart and lung disease detected on thoracic CT scans of HIV patients on HAART 
Journal of the International AIDS Society  2014;17(4Suppl 3):19716.
The aim was to determine the prevalence of lung and heart abnormalities on thoracic CT scans in HIV-infected patients who were treated with antiretroviral therapy (ART).
Material and Methods
Thoracic CT scans of 903 patients infected with HIV (mean age 48±7 yrs, 29% females) were reviewed by three radiologists by consensus. Patients were phenotyped according to smoking status, pack years and years since cessation for ex-smokers. Individuals known to have active lung or heart disease at the time of CT scanning were excluded. Multimorbidity lung and heart disease (MLHD) was defined by the presence of >2 lung or heart abnormalities on the CT scan.
Prevalence of lung abnormalities were: 326 patients (36.1%) with emphysema, 271 (30.0%) with bronchiolitis, 44 (4.9%) with non-calcified lung nodules, 568 (63%) with significant bronchial wall thickening, 150 (16.7%) with bronchiectasis, 9 (1%) with interstitial lung disease. Overall, 445 patients (49.3%) had >2 lung abnormalities. Imaging findings suggestive of prior myocardial infarction (MI) were found in 1.4% (13 patients); 26.6% (240 patients) had CAC scores of 1 to 100, and 9.8% (89 patients) had CAC>100. 13.6% (123 patients) of the patients had CAC>100 and/or previous MI. MLHD was present in 484 patients (53.6%) and among 78 patients (16%) who never smoked. Table 1 describes CT findings according to pack year and stop smoking groups vs never smokers.
MLHD increased proportional to cumulative smoking history (p for trend <0.001) and decreased in proportion to the number of years since smoking cessation (p for trend=0.017). Independent predictors for MLHD were: age (OR=1.07, CI 1.05–1.10), sex (OR=1.59, CI 1.15–2.19), current smoking (OR=1.76, CI 1.08–2.89), and pack-years history of smoking (OR=1.03, CI 1.02–1.05). In patients who never smoked, nadir CD4<200 was significantly associated with MLHD after adjustment for age and sex (OR=1.98, CI 1.98–3.63).
MLHD is common in HIV-infected individuals even in non-smokers. Reduced CD4 count (hence severity of HIV infection) may be an important risk factor for chronic lung and heart disease. Thoracic CT scans may provide an excellent screening tool to detect MLHD in HIV-infected patients.
PMCID: PMC4225346  PMID: 25397462
21.  The Burden of Image Based Emphysema and Bronchiolitis in HIV-Infected Individuals on Antiretroviral Therapy 
PLoS ONE  2014;9(10):e109027.
With the widespread use of anti-retroviral therapy (ART), individuals infected with human immune deficiency virus (HIV) are increasingly experiencing morbidity and mortality from respiratory disorders. However, the prevalence or the risk factors associated with emphysema and bronchiolitis are largely unknown.
Thoracic computed tomography (CT) scans were performed in 1,446 patients infected with HIV who were on ART and who attended a tertiary care metabolic clinic (average age 48 years and 29% females). Detailed history and physical examination including anthropometric measurements were performed. Complete pulmonary function tests were performed in a subset of these patients (n = 364). No subjects were acutely ill with a respiratory condition at the time of CT scanning.
Nearly 50% of the subjects had CT evidence for emphysema, bronchiolitis or both with 13% (n = 195) showing bronchiolitis, 19% (n = 274) showing emphysema and 16% (n = 238) revealing both. These phenotypes were synergistically associated with reduced regular physical activity (p for interaction <.0001). The most significant risk factors for both phenotypes were cigarette smoking, intravenous drug use and peripheral leucocytosis. Together, the area-under-the curve statistics was 0.713 (p = 0.0037) for discriminating those with and without these phenotypes. There were no significant changes in lung volumes or flow rates related to these phenotypes, though the carbon monoxide diffusion capacity was reduced for the emphysema phenotype.
Emphysema and bronchiolitis are extremely common in HIV-infected patients who are treated with ART and can be identified by use of thoracic CT scanning.
PMCID: PMC4212912  PMID: 25354261
22.  Changes in the Bacterial Microbiota in Gut, Blood, and Lungs following Acute LPS Instillation into Mice Lungs 
PLoS ONE  2014;9(10):e111228.
Previous reports have shown that the gastrointestinal (GI) bacterial microbiota can have profound effects on the lungs, which has been described as the “gut-lung axis”. However, whether a “lung-gut” axis exists wherein acute lung inflammation perturbs the gut and blood microbiota is unknown.
Adult C57/Bl6 mice were exposed to one dose of LPS or PBS instillation (n = 3 for each group) directly into lungs. Bacterial microbiota of the bronchoalveolar lavage fluid, blood, and cecum were determined using 454 pyrotag sequencing and quantitative polymerase chain reaction (qPCR) at 4 through 168 hours post-instillation. We then investigated the effects of oral neomycin and streptomycin (n = 8) on the microbiota at 4 and 24 hours post LPS instillation versus control treatment (n = 5 at baseline and 4 hours, n = 7 at 24 hours).
At 24 hours post LPS instillation, the total bacterial count was significantly increased in the cecum (P<0.05); whereas the total bacterial count in blood was increased at 4, 48, and 72 hours (P<0.05). Antibiotic treatment reduced the total bacteria in blood but not in the cecum. The increase in total bacteria in the blood correlated with Phyllobacteriaceae OTU 40 and was significantly reduced in the blood for both antibiotic groups (P<0.05).
LPS instillation in lungs leads to acute changes in the bacterial microbiota in the blood and cecum, which can be modulated with antibiotics.
PMCID: PMC4205020  PMID: 25333938
23.  A Comparison between Droplet Digital and Quantitative PCR in the Analysis of Bacterial 16S Load in Lung Tissue Samples from Control and COPD GOLD 2 
PLoS ONE  2014;9(10):e110351.
Low biomass in the bacterial lung tissue microbiome utilizes quantitative PCR (qPCR) 16S bacterial assays at their limit of detection. New technology like droplet digital PCR (ddPCR) could allow for higher sensitivity and accuracy of quantification. These attributes are needed if specific bacteria within the bacterial lung tissue microbiome are to be evaluated as potential contributors to diseases such as chronic obstructive pulmonary disease (COPD). We hypothesize that ddPCR is better at quantifying the total bacterial load in lung tissue versus qPCR.
Control (n = 16) and COPD GOLD 2 (n = 16) tissue samples were obtained from patients who underwent lung resection surgery, were cut on a cryotome, and sections were assigned for use in quantitative histology or for DNA extraction. qPCR and ddPCR were performed on these samples using primers spanning the V2 region on the 16S rRNA gene along with negative controls. Total 16S counts were compared between the two methods. Both methods were assessed for correlations with quantitative histology measurements of the tissue.
There was no difference in the average total 16S counts (P>0.05) between the two methods. However, the negative controls contained significantly lower counts in the ddPCR (0.55 ± 0.28 16S/uL) than in the qPCR assay (1.00 ± 0.70 16S copies) (P <0.05). The coefficient of variation was significantly lower for the ddPCR assay (0.18 ± 0.14) versus the qPCR assay (0.62 ± 0.29) (P<0.05).
Overall the ddPCR 16S assay performed better by reducing the background noise in 16S of the negative controls compared with 16S qPCR assay.
PMCID: PMC4199711  PMID: 25329701
24.  The role of female hormones on lung function in chronic lung diseases 
BMC Women's Health  2011;11:24.
The prevalence, morbidity, and mortality of inflammatory lung diseases such as asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF) are increasing in women. There is a dearth of data on the biological mechanisms to explain such observations. However, some large epidemiologic studies suggest that lung function fluctuates during the menstrual cycle in female patients with airways disease but not in women without disease, suggesting that circulating estradiol and progesterone may be involved in this process.
In asthma, estradiol shuttles adaptive immunity towards the TH2 phenotype while in smokers estrogens may be involved in the generation of toxic intermediate metabolites in the airways of female smokers, which may be relevant in COPD pathogenesis. In CF, estradiol has been demonstrated to up-regulate MUC5B gene in human airway epithelial cells and inhibit chloride secretion in the airways. Progesterone may augment airway inflammation.
Taken together, clinical and in-vivo data have demonstrated a sex-related difference in that females may be more susceptible to the pathogenesis of lung diseases. In this paper, we review the effect of female sex hormones in the context of these inflammatory airway diseases.
PMCID: PMC3129308  PMID: 21639909
lung function; menstrual cycle; sex hormones; asthma; cystic fibrosis; COPD
25.  Estradiol Increases Mucus Synthesis in Bronchial Epithelial Cells 
PLoS ONE  2014;9(6):e100633.
Airway epithelial mucus hypersecretion and mucus plugging are prominent pathologic features of chronic inflammatory conditions of the airway (e.g. asthma and cystic fibrosis) and in most of these conditions, women have worse prognosis compared with male patients. We thus investigated the effects of estradiol on mucus expression in primary normal human bronchial epithelial cells from female donors grown at an air liquid interface (ALI). Treatment with estradiol in physiological ranges for 2 weeks caused a concentration-dependent increase in the number of PAS-positive cells (confirmed to be goblet cells by MUC5AC immunostaining) in ALI cultures, and this action was attenuated by estrogen receptor beta (ER-β) antagonist. Protein microarray data showed that nuclear factor of activated T-cell (NFAT) in the nuclear fraction of NHBE cells was increased with estradiol treatment. Estradiol increased NFATc1 mRNA and protein in ALI cultures. In a human airway epithelial (1HAE0) cell line, NFATc1 was required for the regulation of MUC5AC mRNA and protein. Estradiol also induced post-translational modification of mucins by increasing total fucose residues and fucosyltransferase (FUT-4, -5, -6) mRNA expression. Together, these data indicate a novel mechanism by which estradiol increases mucus synthesis in the human bronchial epithelium.
PMCID: PMC4070981  PMID: 24964096

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