Faculty Bibliography

There is an increasing awareness of the role of distal airways in the pathophysiology of obstructive lung diseases including asthma and chronic obstructive pulmonary disease. We hypothesize that during induced bronchoconstriction: 1) disparity between distal and proximal airway reactivity may occur; and 2) changes in distal airway function may explain symptom onset in subjects with minimal FEV(1) change. 185 subjects underwent methacholine challenge testing (MCT). In addition to spirometry, oscillometry was performed at baseline and after maximum dose of methacholine; 33/185 also underwent oscillometry after each dose. Oscillometric parameters included resistance at 5 and 20 Hz (R(5,) R(20)) and heterogeneity of distal airway mechanics assessed by frequency dependence of resistance 5-20 Hz (R(5-20)) and reactance area (AX). R(5) varied widely during MCT (range -0.8 - 11.3 cmH(2)O/L/s) and correlated poorly with change in FEV(1) (r = 0.17). Changes in R(5) reflected changes in both R(20) and R(5-20) (r = 0.59, p<0.05; r = 0.87, p<0.0001). However, R(20) increased only 0.3 cmH(2)O/L/s, while R(5-20) increased 0.7 cmH(2)O/L/s for every 1cmH(2)O/L/s change in R(5,) indicating predominant effect of distal airway mechanics. 9/33 subjects developed symptoms despite minimal FEV(1) change (<5%), while R(5) increased 42% due to increased distal airway heterogeneity. These data indicate disparate behavior of proximal airway resistance (FEV(1) and R(20)) and distal airway heterogeneity (R(5-20) and AX). Distal airway reactivity may be associated with methacholine-induced symptoms despite absence of change in FEV(1). This study highlights the importance of disparity between proximal and distal airway behavior, which has implications in understanding pathophysiology of obstructive pulmonary diseases and their response to treatment

Community-acquired pneumonia affects approximately 4 million people in the United States, with 40,000 deaths per year. The incidence is increased about 35-fold in HIV-infected individuals, and this rate has decreased since the antiretroviral era has begun. Bacterial pneumonia has decreased from 5 to 20 cases per 100 person-years to less than 1 to 5 cases per 100 person-years in the era of antiretroviral therapy. HIV-1 infection impairs the function of neutrophils in the lung and infects CD4(+) cells and alveolar macrophages. Opportunistic infections dramatically increase local HIV replication in the lung cells, especially alveolar macrophages and CD4(+) cells. This enhanced replication increases viral mutations and provides opportunities for viral escape from latent reservoirs. Mortality is increased with more comorbidities in this highly susceptible population. Immunization with vaccines is recommended, especially pneumococcal vaccines, although the vaccine itself may stimulate viral replication. Recent studies show that the lower respiratory tract is a microbial reservoir in HIV-infected individuals rather than being a sterile environment, as originally thought. This may provide new opportunities for preventing opportunistic infections in HIV-infected subjects. Bacterial pneumonia presents an ongoing challenge in these high-risk individuals, particularly in studying the functions of the innate and acquired immune response

The spectrum of lung diseases associated with HIV is broad, and many infectious and noninfectious complications of HIV infection have been recognized. The nature and prevalence of lung complications have not been fully characterized since the Pulmonary Complications of HIV Infection Study more than 15 years ago, before antiretroviral therapy (ART) increased life expectancy. Our understanding of the global epidemiology of these diseases in the current ART era is limited, and the mechanisms for the increases in the noninfectious conditions, in particular, are not well understood. The Longitudinal Studies of HIV-Associated Lung Infections and Complications (Lung HIV) Study (ClinicalTrials.gov number NCT00933595) is a collaborative multi-R01 consortium of research projects established by the National Heart, Lung, and Blood Institute to examine a diverse range of infectious and noninfectious pulmonary diseases in HIV-infected persons. This article reviews our current state of knowledge of the impact of HIV on lung health and the development of pulmonary diseases, and highlights ongoing research within the Lung HIV Study

Rationale: Lung cancer is the leading cause of death from all types of cancer worldwide. The high mortality rate is partly attributed to the lack of methods for early detection and identification of patients who are at risk for developing disease. Since adenocarcinoma in the lung periphery is the most common type of lung cancer and the earliest morphologic evidence of changes in the airways associated with chronic cigarette smoking is in the peripheral airways, we hypothesize that identifying gene expression signatures in the peripheral airways will provide the best approach for better understanding field carcinogenesis of lung adenocarcinomas. To this end, we performed gene and miRNA profiling of cells obtained from brushings of peripheral airways of smokers with and without lung adenocarcinomas. These studies will provide not only mechanistic insights into field carcinogenesis of adenocarcinoma, but more importantly, potential tools for the early detection of lung adenocarcinomas. To this end, we performed gene expression profiling of the peripheral small airway epithelium of patients with lung cancer and compared it to that of non-cancerous smokers to identify gene expression signatures of field cancerization in lung cancer. Methods: Fiberoptic bronchoscopies with brushings were used to collect peripheral airway epithelial cells from the 10^th-12^th-order bronchi in non-cancerous smokers or from the unaffected lobe of suspected lung cancer patients. Clinical samples obtained from the suspected lung cancer patients confirmed the histological diagnosis of primary lung cancer. Using Affymetrix HG-U133A Plus 2.0 microarrays, we performed gene expression profiling of over 47,000 genes using total RNA isolated from small airway epithelial cells obtained from brushings of both lung cancer patients and non-cancerous smokers. Results: Microarray analysis of the gene expression profile in the peripheral airway epithelium demonstrated several up-regulated and down-regulated genes which could represent significant alterations in lung cancer. Significantly up-regulated genes included pro-platelet basic protein, gremlin 1, aminolevulinate synthase 2, sparc/osteonectin, and wnt inhibitory factor 1 while down-regulated genes include cytochrome P450 1B1 and 2A6, mucin 2, aldedyhe dehydrognease 3A1, and glutathione peroxidase 2 (p value < 0.05). Conclusion: We had identified several up-regulated and down-regulated genes in peripheral airway epithelial cells of cancer patients which were significantly different when compared to non-cancerous smokers. Identification of the gene expression signatures in field carcinogenesis will not only provide mechanistic insights into lung cancer, but also allow us to identify novel biomarkers for the early detection of lung cancer

Introduction: Interferon gamma release assays (IGRA) have been widely accepted to replace the tuberculin skin test (TST). Data from the Botswana isoniazid preventative therapy (IPT) study showed that in HIV infected individuals only those who were TST positive benefitted from IPT (92% reduction in TB incidence.) We set out to compare the utility of IGRA's (QuantiFERON Gold-in-tube (QFT-GIT) and TSPOT-TB (TSPOT)) and the TST in a high TB-HIV burden setting. Methods: TST (2TU PPD), QFT-GIT and TSPOT-TB where performed in a prospective cohort of 200 HIV positive individuals on ARV's in Cape Town South Africa. Multivariate analysis was performed to assess associations with clinical, demographic and HIV associated (ARV usage, CD4 count, viral load) factors. Results: The participants had a mean (SD) age of 38.4(8.4) years, were predominantly black African (81.3%), female (53.4%) and 32.9% were ever smokers. The median (range) length of time on ARV's 2.1(0.25-7.56) years with median (range) CD4 count of 380(25-1227). Twenty eight (18.6%) participants were TST positive (>5mm), 45(30%) TSPOT-TB positive and 62(41.3%) QFT positive. The agreement between tests was generally fair/poor: QFT-TSPOT: 72%; kappa 0.39(95%CI 0.23-0.55), QFT-TST: 68%; kappa 0.27(95%CI 0.10- 0.44), TSPOT-TST 67%; kappa 0.13(95%CI -0.08 - 0.33). Using the TST as the gold standard, QFT had a sensitivity of 81.2%, specificity of 65.6% and TSPOT 47.6% & 70.8% respectively. LTBI test status was not different in those with/without a history of previous TB or history of smoking. Conclusions: IGRA's only correctly identified 2/3 of TST positive persons. If used alone, potentially a third of HIV infected individuals will receive unnecessary IPT. Longitudinal follow up studies are required to define the utility of IGRAs in the treatment of LTBI in HIV infected persons

Introduction: Lung cancer is the leading causes of cancer death with an overall survival of 15% at 5 years. The poor survival is primarily because most of the patients present at advanced stage when a surgical resection is no longer feasible. Tobacco smoking is the single most important cause of lung cancer. We hypothesized that sputum would be a specific and sensitive biomarker that is easily accessible and non-invasive to detect lung tumorigenesis at early stage among high-risk smokers. Rationale: Sputum contains upper and lower airway epithelial cells, suggesting the molecular alterations identified in sputum likely reflects tumor-associated changes in the lung. Three genes were chosen to be examined using DNA derived from sputum based on their implication in lung tumorigenesis. STK11 is a serine/threonine kinase that regulates cell polarity and metabolism and functions as a tumor suppressor. Germline mutation of STK11 results in the Peutz-Jeghers syndrome, a familial cancer syndrome characterized an increased risk for epithelial cancers, including non-small cell lung cancer (NSCLC) where STK11 is found to be mutated at 30-40% frequency. CDKN2A (also known as p16) is another tumor suppressor protein that plays an important role in regulating the cell cycle, and mutations in p16 increase the risk of developing a variety of cancers including lung cancer and importantly, its loss of function has been implicated in the early stage of tumorigenesis. p53, a tumor suppressor that is the most frequently mutated gene in lung adenocarcinoma, responds to diverse cellular stresses to regulate target genes that induce cell cycle arrest, apoptosis, senescence, or DNA repair. This DNA-binding protein is postulated to bind to a p53-binding site and activate expression of downstream genes that inhibit growth and/or invasion, which is often impaired by mutations identified in various human cancers. Methods: Spontaneous sputum was collected from normal smokers and lung cancer patients and processed to extract genomic DNA. Primers were designed to span exons 1-2 in CDKN2A, exons 2-9 in TP53 and exons 1-9 in STK11. Amplicons were analyzed by direct sequencing. Results: We identified numerous sequence variations in all three genes examined, including verified polymorphisms and mutations in the introns and exons. Most frequently, we detected G to A substitution in the 5' UTR region in CDKN2A and C to G substitution, which results in P72R in exon 4 in TP53. Conclusion: This panel of genes may be useful biomarkers for early detection of lung cancer among smokers

Introduction:Regulatory T cells (Treg) play important roles in immunological self-tolerance, and are functionally immunosuppressive subsets of T cells. Th17 cells are critical in the defense against microbes, particularly at mucosal surfaces. It has been shown that the balance between Treg and Th17 cells is a key factor that regulates helper T-cell (CD4⁺ or Th) function. However, there is limited information on the balance between Treg and Th17 cells in bronchoalveolar lavage (BAL). We investigated the distribution of Th17 cells in relation to Treg in PBMC and BAL of healthy volunteers, emphysema patients and HIV-1 infected patients. Methods:BAL lymphocytes were obtained by plating BAL cells for >=1 hour to remove adherent alveolar macrophages. PBMC were isolated by Ficoll gradient fractionation. BAL and PB lymphocytes were stimulated with PMA and ionomycin, treated with monensin, permeabilized, then labeled with PerCP-anti-CD4, PE-anti-IL-17 and Alexa Fluor 647 anti-Foxp3, and analyzed on a FACSCalibur to determine the percentage of CD4⁺ lymphocytes expressing IL-17 and Foxp3 (mean+/-SD). Results:Ten subjects were available for analysis (2 healthy volunteers, 5 emphysema and 3 HIV-1 infected subjects). Both PB and BAL Th cells presented a wide range of FoxP3⁺ cells (19.2+/-18.6 and 6.3+/-5.9 respectively) and IL-17⁺ cells (9.5+/-8.1 and 8.8+/-4.6 respectively). There was a greater percentage of FoxP3⁺ in the HIV-infected group compared to the healthy volunteer and emphysema groups (11.7+/-6.4 vs. 1.7+/-1.1 and 4.9+/-4.7 respectively). Similarly, there was a trend towards higher percentage of IL-17⁺ cells in the BAL of HIV-infected subjects compared to the healthy volunteer and emphysema subjects (10.8+/-3.6 vs. 5.6+/-0.9 and 8.9+/-5.8 respectively). When the expression of FoxP3⁺ and IL-17⁺ cells in BAL was compared for each subject, a direct correlation with an r2 of 0.36 and a p-value of 0.06 was found Conclusions:We observed a relative preservation of FoxP3⁺ and IL-17⁺ cells in BAL CD4⁺ lymphocytes, despite prior evidence suggesting a preferential loss of both Treg and Th17 subsets in PBMC of HIV-1 infected subjects. The co-ordinated expression of these subsets in BAL Th cells warrants further investigation to evaluate its immune significance in the alveolar compartment

Introduction The lung is a common target of HIV-associated morbidity, but there are few studies of long-term pulmonary consequences of HIV infection after successful introduction of antiretroviral drugs (ARVs), particularly in developing countries with high rates of tuberculosis. Methods: A cross-sectional analysis of a prospective cohort of 152 participants with HIV infection, stable on antiretroviral therapy for at least 3 months, and without features of acute respiratory disease, was performed. Clinical and demographic information was recorded in a respiratory questionnaire, and pulmonary function tests including flow-volume loops before and after bronchodilator, body plethysmography and measurement of diffusing capacity were performed. Results: The participants were predominantly black African (81.3%) and female (53.4%); mean age was 38.4 (SD+/-8.4) years, and 32.9% had a history of tobacco smoking. The median duration of time on ART was 2.1 years (range 0.25-7.56), and the median CD₄ was 380 (range 25-1227). Forty-one percent reported a history of previous tuberculosis, and only 3 subjects previous Pneumocystis pneumonia. None were users of intravenous drugs. Respiratory symptoms were reported in 31% of participants, and any respiratory symptom (cough, phlegm, wheeze or dyspnea) was strongly associated with current smoking (OR 2.556, 95% CI 1.05-6.211, P=0.04). Irreversible airflow obstruction was present in 7%, and associated with ever smoking (OR 6.352, 95% CI 1.56-25.90, P=0.01). Impairment of diffusing capacity for carbon monoxide (DL_CO <70% predicted) was present in 57%, and associated with a history of previous tuberculosis (OR 2.01, 95% CI 1.00-4.00, P=0.47), but not with current or ever smoking. Conclusions: In this relatively young cohort of treated AIDS patients, a high proportion of whom were female, evidence of smoking-induced symptoms and airflow limitation was observed. The most common lung function abnormality, however, was an impairment in diffusing capacity, which was associated with previous tuberculosis. Further research to define structure/function relationships and the role of opportunistic infections and other risk factors is underway

Introduction The NYU Lung Cancer Biomarker Center recruited 1054 smokers (<=20 pack-years) between 03/2000 and 06/2010 and screened them with CT-scans and respiratory questionnaires. Questionnaires contained demographic characteristics, occupational exposures, lifestyle information including smoking history and alcohol use, personal and family medical history, and pulmonary symptoms. CT-scans showed the disease status and emphysema. We hypothesized that information collected in the questionnaires would be associated with the subject's disease status. Methods The 1054 Subjects were classified into 4 groups based on the results of enrollment CT-scans. This categorization showed 331 subjects with solid nodule(s) only, 95 with ground glass opacity (GGO) only, 126 with both solid nodule(s) and GGO(s), and the remaining 502 subjects with no nodules. Chi-squared tests were used to assess the relationship between disease category and each single predictor. Polytomous logistic regression was used to assess the association between disease category and multiple predictors. Forward/backward stepwise regression was used in model selection. Results Univariate analysis showed that gender (CMH =8.7092, p-value=0.0032), age (CMH=29.2219, p-value<0.0001), marijuana smoking (CMH=10.9024, p-value=0.0010), emphysema (CMH=9.0929, p-value=0.0026) and years of smoking (CMH=15.4712, p-value<0.0001) were significantly associated with disease categories. Further tests showed that years of smoking was highly associated with age, and did not contribute to prediction of disease category when age was included in the model, as shown by our multivariate analysis. In multivariate analysis, increasing age, gender (male) and history of emphysema were significant predictors of worsening disease class. Moreover, when we stratified by gender, the analysis indicated that in males, older men were more likely to develop solid nodules (OR=1.275, 95% CI [1.0063, 1.0490]) and more likely to have mixed nodules (OR= 1.0664, 95% CI= [1.0331, 1.1008]) than younger men. Males with emphysema were far more likely to have solid nodules compared with those without emphysema (OR= 1.9678, 95% CI= [1.3128, 2.9495]). Our analysis also revealed that in females, age was the only significant risk factor: older women were more likely to have mixed nodules than younger women (OR= 1.0593, 95% CI= [1.0274, 1.0922]). It is notable that all smoking related variables were not significantly associated with nodule class in our multivariable analysis. Conclusion Our analysis suggests that age, gender and emphysema play a critical role in the development of disease (solid nodule or GGO). Also, our analysis has shown that smoking is not likely to play a major role in the development of the disease in this high risk cohort