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1.  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
2.  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
3.  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
4.  Plasma sCD14 as a Biomarker to Predict Pulmonary Exacerbations in Cystic Fibrosis 
PLoS ONE  2014;9(2):e89341.
One in four cystic fibrosis (CF) patients diagnosed with a pulmonary exacerbation will not recover their baseline lung function despite standard treatment. This highlights the importance of preventing such events. Clinical decision-making can be improved through a simple blood test that predicts individuals at elevated short-term risk of an exacerbation.
We obtained plasma samples from 30 stable CF patients from the St. Paul’s Hospital Adult CF Clinic (Vancouver, Canada). For 15 patients, an additional plasma sample was obtained during an exacerbation. Soluble CD14 (sCD14) and C-reactive protein (CRP) were quantified using ELISA kits. Myeloperoxidase (MPO), interleukin(IL)-6, IL-1β, monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF), and granulocyte colony-stimulating factor (G-CSF) were quantified using Luminex™ immunoassays. Stable state biomarker levels were examined in their ability to predict individuals that would experience a pulmonary exacerbation requiring intravenous (IV) antibiotics within 4 months. Paired stable and exacerbation plasma biomarker levels were also compared.
sCD14 levels were significantly higher in patients that experienced a pulmonary exacerbation requiring IV antibiotics within 4 months (p = 0.001). sCD14 cut-off value of 1450 ng/mL was associated with an area under the curve of 0.91 (95% CI 0.83–0.99) for predicting an exacerbation within 4 months of a stable visit, with a sensitivity of 100% and specificity of 82%. Plasma sCD14 levels were significantly higher during exacerbations than during periods of clinical stability (p = 0.03).
Plasma sCD14 is a promising biomarker for identifying CF patients who will exacerbate within 4 months of a stable visit but requires further study in larger, independent cohorts.
PMCID: PMC3930718  PMID: 24586701
5.  The Relation of Serum Myeloperoxidase to Disease Progression and Mortality in Patients with Chronic Obstructive Pulmonary Disease (COPD) 
PLoS ONE  2013;8(4):e61315.
Myeloperoxidase is a strong oxidant stored in primary granules of neutrophils with potent antibacterial and proatherogenic properties. Myeloperoxidase has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). However, the relationship of myeloperoxidase to health outcomes in COPD is not well known. We measured serum myeloperoxidase levels from 4,677 subjects with mild to moderate airflow limitation in the Lung Health Study. Using a Cox proportional hazards model, we determined the relationship of serum myeloperoxidase concentration to the risk of all-cause and disease specific causes of mortality. We found that serum myeloperoxidase concentrations were significantly related to accelerated decline in forced expiratory volume in 1 second (FEV1) over 11 years of follow-up (p<0.0001), and this association persisted after adjustments for age, sex, race, baseline FEV1, and smoking status (p = 0.048). Serum myeloperoxidase concentrations were also associated with increased risk of cardiovascular mortality (p = 0.036). Individuals in the highest quintile of myeloperoxidase had a hazard ratio of cardiovascular mortality of 1.90 (95% confidence interval 1.00–3.58; p = 0.049) compared with those in the lowest quintile, which was particularly notable in patients who continued to smoke (adjusted p-value of 0.0396). However, serum myeloperoxidase concentration was not related to total mortality, respiratory mortality, or deaths from malignancies. In conclusion, increased serum myeloperoxidase levels are associated with rapid lung function decline and poor cardiovascular outcomes in COPD patients, which support the emerging role of myeloperoxidase in the pathogenesis of COPD progression and cardiovascular disease.
PMCID: PMC3630209  PMID: 23637811
6.  Serum PARC/CCL-18 Concentrations and Health Outcomes in Chronic Obstructive Pulmonary Disease 
Rationale: There are no accepted blood-based biomarkers in chronic obstructive pulmonary disease (COPD). Pulmonary and activation-regulated chemokine (PARC/CCL-18) is a lung-predominant inflammatory protein that is found in serum.
Objectives: To determine whether PARC/CCL-18 levels are elevated and modifiable in COPD and to determine their relationship to clinical end points of hospitalization and mortality.
Methods: PARC/CCL-18 was measured in serum samples from individuals who participated in the ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) and LHS (Lung Health Study) studies and a prednisolone intervention study.
Measurements and Main Results: Serum PARC/CCL-18 levels were higher in subjects with COPD than in smokers or lifetime nonsmokers without COPD (105 vs. 81 vs. 80 ng/ml, respectively; P < 0.0001). Elevated PARC/CCL-18 levels were associated with increased risk of cardiovascular hospitalization or mortality in the LHS cohort and with total mortality in the ECLIPSE cohort.
Conclusions: Serum PARC/CCL-18 levels are elevated in COPD and track clinical outcomes. PARC/CCL-18, a lung-predominant chemokine, could be a useful blood biomarker in COPD.
Clinical trial registered with (NCT 00292552).
PMCID: PMC3114051  PMID: 21216880
biomarker; chronic obstructive pulmonary disease; PARC/CCL-18; chemokine
7.  The Relationship between Telomere Length and Mortality in Chronic Obstructive Pulmonary Disease (COPD) 
PLoS ONE  2012;7(4):e35567.
Some have suggested that chronic obstructive pulmonary disease (COPD) is a disease of accelerated aging. Aging is characterized by shortening of telomeres. The relationship of telomere length to important clinical outcomes such as mortality, disease progression and cancer in COPD is unknown. Using quantitative polymerase chain reaction (qPCR), we measured telomere length of peripheral leukocytes in 4,271 subjects with mild to moderate COPD who participated in the Lung Health Study (LHS). The subjects were followed for approximately 7.5 years during which time their vital status, FEV1 and smoking status were ascertained. Using multiple regression methods, we determined the relationship of telomere length to cancer and total mortality in these subjects. We also measured telomere length in healthy “mid-life” volunteers and patients with more severe COPD. The LHS subjects had significantly shorter telomeres than those of healthy “mid-life” volunteers (p<.001). Compared to individuals in the 4th quartile of relative telomere length (i.e. longest telomere group), the remaining participants had significantly higher risk of cancer mortality (Hazard ratio, HR, 1.48; p = 0.0324) and total mortality (HR, 1.29; p = 0.0425). Smoking status did not make a significant difference in peripheral blood cells telomere length. In conclusion, COPD patients have short leukocyte telomeres, which are in turn associated increased risk of total and cancer mortality. Accelerated aging is of particular relevance to cancer mortality in COPD.
PMCID: PMC3338848  PMID: 22558169
8.  Connective Tissue-Activating Peptide III: A Novel Blood Biomarker for Early Lung Cancer Detection 
Journal of Clinical Oncology  2009;27(17):2787-2792.
There are no reliable blood biomarkers to detect early lung cancer. We used a novel strategy that allows discovery of differentially present proteins against a complex and variable background.
Mass spectrometry analyses of paired pulmonary venous-radial arterial blood from 16 lung cancer patients were applied to identify plasma proteins potentially derived from the tumor microenvironment. Two differentially expressed proteins were confirmed in 64 paired venous-arterial blood samples using an immunoassay. Twenty-eight pre- and postsurgical resection peripheral blood samples and two independent, blinded sets of plasma from 149 participants in a lung cancer screening study (49 lung cancers and 100 controls) and 266 participants from the National Heart Lung and Blood Institute Lung Health Study (45 lung cancer and 221 matched controls) determined the accuracy of the two protein markers to detect subclinical lung cancer.
Connective tissue-activating peptide III (CTAP III)/ neutrophil activating protein-2 (NAP-2) and haptoglobin were identified to be significantly higher in venous than in arterial blood. CTAP III/NAP-2 levels decreased after tumor resection (P = .01). In two independent population cohorts, CTAP III/NAP-2 was significantly associated with lung cancer and improved the accuracy of a lung cancer risk prediction model that included age, smoking, lung function (FEV1), and an interaction term between FEV1 and CTAP III/NAP-2 (area under the curve, 0.84; 95% CI, 0.77 to 0.91) compared to CAPIII/NAP-2 alone.
We identified CTAP III/NAP-2 as a novel biomarker to detect preclinical lung cancer. The study underscores the importance of applying blood biomarkers as part of a multimodal lung cancer risk prediction model instead of as stand-alone tests.
PMCID: PMC2698017  PMID: 19414677
9.  Associations of IL6 polymorphisms with lung function decline and COPD 
Thorax  2009;64(8):698-704.
Interleukin-6 (IL6) is a pleiotropic pro-inflammatory and immunomodulatory cytokine which likely plays an important role in the pathogenesis of COPD. There is a functional single nucleotide polymorphism (SNP), −174G/C, in the promoter region of IL6. We hypothesized that IL6 SNPs influence susceptibility for impaired lung function and COPD in smokers.
Seven and 5 SNPs in IL6 were genotyped in two nested case-control samples derived from the Lung Health Study (LHS) based on phenotypes of rate of decline of forced expiratory volume in one second (FEV1) over 5 years and baseline FEV1 at the beginning of the LHS. Serum IL6 concentrations were measured for all subjects. A partially overlapping panel of 9 IL6 SNPs was genotyped in 389 COPD cases from the National Emphysema Treatment Trial (NETT) and 420 controls from the Normative Aging Study (NAS).
In the LHS, three IL6 SNPs were associated with FEV1 decline (0.023 ≤ P ≤ 0.041 in additive models). Among them the IL6_−174C allele was associated with rapid decline of lung function. The association was more significant in a genotype-based analysis (P = 0.006). In the NETT-NAS study, IL6_−174G/C and four other IL6 SNPs, all of which are in linkage disequilibrium with IL6_−174G/C, were associated with susceptibility to COPD (0.01 ≤ P ≤ 0.04 in additive genetic models).
Our results suggest that the IL6_−174G/C SNP is associated with rapid decline of FEV1 and susceptibility to COPD in smokers.
PMCID: PMC2859187  PMID: 19359268
genetic polymorphism; IL6; forced expiratory volume in one second (FEV1); lung function; chronic obstructive pulmonary disease (COPD)
10.  Progression of Airway Dysplasia and C-Reactive Protein in Smokers at High Risk of Lung Cancer 
Rationale: Chronic inflammation has been implicated in the development of airway dysplasia and lung cancer. It is unclear whether circulating biomarkers of inflammation could be used to predict progression of airway dysplasia.
Objective: We determined whether circulating levels of C-reactive protein (CRP) or other inflammatory biomarkers could predict progression of bronchial dysplasia in smokers over 6 mo.
Methods: The plasma levels of CRP, interleukins 6 and 8, and monocyte chemoattractant protein 1 were measured at baseline in 65 ex- and current smokers who had at least one site of bronchial dysplasia > 1.2 mm in size. Additional bronchial biopsies were taken after 6 mo from the same sites where dysplastic lesions were discovered at baseline. Progressive dysplastic lesions were defined as worsening of the dysplastic lesion by at least two grades or development of new dysplastic lesions.
Results: Half of the participants developed progressive dysplastic lesions after 6 mo. The baseline CRP levels in these participants were 64% higher than those without progressive disease (p = 0.027). Only one of eight (13%) participants with CRP ⩽ 0.5 mg/L developed progressive disease, whereas 31 of 57 (54%) participants with CRP > 0.5 mg/L developed progressive disease (p = 0.011). The odds of developing progressive disease were 9.6-fold higher in the latter than in the former group.
Conclusion: Plasma CRP, in concert with lung function and pack-years of smoking, appears to have excellent predictive powers in identifying participants with bronchial dyplastic lesions whose lesions progress to more advanced stages of dysplasia.
PMCID: PMC2662937  PMID: 16339918
airway dysplasia; C-reactive protein; lung inflammation
11.  Asthma control and management in the community 
Canadian Family Physician  2006;52(6):751.
To determine whether there was any change in indices of asthma control in population-based samples of patients with asthma between 1997 and 2002.
We examined asthma control and treatment in the community using two cross-sectional studies carried out 5 years apart in 1997 and 2002. Pharmacists handed out the questionnaires to patients with asthma; patients completed the questionnaires themselves.
Community pharmacies in Alberta.
Patients with physician-confirmed asthma attending pharmacies to fill prescriptions for asthma medications.
Asthma control.
In 1997 and 2002, 301 and 340 completed questionnaires were received, respectively. Mean age of respondents was 42 and 39 years and the female-to-male ratio was 1.3:1 and 1.4:1, respectively. Overall asthma control was achieved by 27% (1997) and 31% (2002) of subjects, a non-significant change. Regular inhaled corticosteroid use was reported by 63% (1997) and 65% (2002) of subjects; mean daily dose of inhaled corticosteroids reported decreased from 920 μg in 1997 to 765 μg in 2002 (P < .02), which might reflect adoption of the newer guideline recommendation for lower-dose inhaled corticosteroids in combination therapy rather than a decrease in severity of asthma. Fewer respondents reported being hospitalized for asthma in 2002 (P = .02). Self-management plans were used by 7% and 5% of subjects in 1997 and 2002, respectively.
In general, asthma control and use of inhaled corticosteroids was similar in 1997 and 2002. There was no evidence that patient education on asthma had increased. Asthma control was poor in 1997 and had not improved by 2002.
PMCID: PMC1780155  PMID: 17273483

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