Faculty Bibliography

Rationale: The use of culture-independent techniques to evaluate resident microbial communities in the lung has opened opportunities to evaluate host response phenotype in health and disease. Background environmental microbiome found in saline and bronchoscope prior to bronchoscopy is characterized by high relative abundance of Propionibacterium. Our preliminary data from the lung microbiome project suggest that substitution of background environmental microbiome by Prevotella or Streptococcus microbiome is associated with higher inflammation. We hypothesize that patients with emphysema who have asymmetric disease on CT will have disappearance of background environmental microbiome in the more affected lung segments. We will also evaluate whether background environmental microbiome is associated with lower inflammation (neutrophil counts, and chemo-attractant cytokines). Methods: Subjects with emphysema were enrolled for research bronchoscopy from NYU/EDRN cohort and CT scans were classified as symmetrical or asymmetrical lung disease. Broncho-alveolar lavages (BAL) were obtained from the right and left lung. Sequencing of 300 bp 16S rDNA included V1-V2 region, performed with 454 pyrosequence. Propionibacterium was used as a marker of background environmental microbiome. Cytokines in BAL fluid will be assayed using Human Cytokine Panel I (Millipore). Results: To date, 15 subjects had sequence data from two segments of different lungs (5 normal volunteers, 6 symmetrical lung disease patients, and 4 asymmetrical lung disease patients). Healthy volunteers were younger than subjects with emphysema (41 +/- 11, 61 +/- 6 respectively, p = 0.003). Although no significant difference in FEV1 was observed, emphysema groups trended to have lower FEV1/FVC (p=ns). There were no differences in high relative abundant taxa (greater than 0.05) between the right and left lung of normal volunteers and emphysema subjects with symmetrical lung disease. However, despite the small n, emphysema subjects with asymmetrical lung disease trended to have higher relative abundance of background environmental microbiome in lung segments with less disease ( Propionibacterium relative abundance = 0.13 +/- 0.04 for segments with less disease as compared with 0.03 +/- 0.04 in the more disease segments, p < 0.08). We will complete sequence in 5 more emphysema subjects and compare microbiota with in-vivo BAL cytokines. Conclusions: Patients with observable asymmetrical lung disease have lower background environmental microbiome in more diseased lung when compared to the less diseased side. This difference was not observed in normal volunteers and patients with symmetrical lung disease. Disappearance of background environmental microbiome in more diseased lung segments suggests higher airway colonization, which might be associated with subclinical inflammation

Rationale: While bacterial colonization leads to airway inflammation and accelerated airway obstruction in advanced COPD, its role in early disease is not well understood. Major limitations have been the ability to study airway colonization in early COPD and measurements of in vivo cytokines levels in the lung. Here, we used a pyrosequence approach for 16s rDNA to study the airway microbiome and a concentration technique to achieve measurable levels of cytokines in BAL fluid from early emphysema and normal volunteers. We hypothesize that the microbiome of early emphysema will be characterized by the presence of potential pathogens that are associated with subclinical inflammation. Methods: CT-scan defined emphysema. Supraglotic and broncho-alveolar lavage (BAL) samples were obtained with two different bronchoscopes. Bacteria speciation was performed with 454 sequencing of rDNA. BAL differential was performed on diff quick stained cytospine slides. BAL was concentrated 50 fold by lyophilization and cytokes were measured using Luminex. Results: 24 subjects were available for analysis (8 healthy normal volunteers and 16 with emphysema). All emphysema subjects were ex-smokers (normal 1+/-0.5 vs. 39+/-20 pack-yr., p=0.019). Lung function of emphysema subjects was characterized by lower FEV1/FVC (78.9+/-5.1 vs. 69.6+/-6.1, p=0.001) and hyperinflation (TLC=87.7+/-10.3 vs. 104.3+/-15.2% predicted, p=0.016). Background environmental microbiome, present in "sterile" saline, is enriched with Staphylococcus and Propionobacterium rDNA (Figure 1 right panel). Supraglotic microbiome is enriched with Prevotella and Streptococcus (left panel). Individuals' BAL microbiome varied from a microbiome more similar to supraglotic with higher relative abundance of Prevotella to a background microbiome (middle panel). In this small sample there was a non-significant trend to higher relative abundance of Prevotella in emphysema vs. normal (p=0.078). There was significant positive correlation between Prevotella and BAL inflammatory cytokines (r2=0.48,p<0.001 and r2=0.22,p<0.02 for IL-1alpha and IL-8 respectively, Figure 2 panel A and B). Furthermore, Prevotella directly correlates with Neutrophils in lung (r2=0.24,p=0.02, Panel C). Conclusions: This data shows that inflammatory cytokines are produced and neutrophils recruited to the alveolar space when the lung and supraglotic microibome are similar. In patients with Prevotella, the bacteria has been present long enough to produce subclinical inflammation. It is therefore unlikely that the Prevotella microbiome is due to carryover during bronchoscopy. In individuals with a BAL microbiome similar to saline, poor sinal-to-noise ratio prevents investigation of the lung microbiome. The Prevotella microbiome more common in emphysema is associated with increased bronco-alveolar cytokines and neutrophils, suggesting an immunological response to this lung microbiome. (Figure Presented)

Rationale: Cigarette smoke causes a field of injury and molecular changes in the airways even in histologically normal areas termed "field cancerization" which describes the site(s) of neoplasia and adjacent normal tissue with molecular abnormalities in common. MicroRNAs ( miRNAs) are small, non-coding RNAs that act as post-transcriptional regulators of gene expression by recognizing target sites in the 3' untranslated regions (3'UTRs) via incomplete base-pairing and induce mRNA degradation or translational repression. Deregulation of miRNAs has been linked to cancer initiation and progression, and miRNAs may act as tumor suppressor genes or oncogenes. We hypothesized that miRNA expression in the peripheral airways of smokers with lung cancer is distinct from that of smokers without lung cancer and therefore, miRNAs can be used as biomarkers for the early detection of lung cancer. Methods: We collected human peripheral airway epithelial cells by bronchoscopic brushing from the unaffected lung of thirteen smokers with lung adenocarcinoma and twelve control smokers. Total RNA was extracted from the peripheral airway epithelial cells by miRNAeasy and miRNA profiling was performed using the TaqMan Quantitative qRT-PCR miRNA Assay. Results: Comparison of miRNA levels in peripheral airway epithelial cells from smokers with or without lung cancer demonstrated 53 miRNAs that were significantly different (p<0.05) between the two groups. The majority of miRNAs were up-regulated (41 miRNAs) in lung cancer patients, including miR-21, miR-26a, miR-31, miR-34c, and miR-205. Down-regulated miRNAs included let-7b, let-7e, and miR-126. Several of the miRNAs with increased expression are of interest: miR-21 inhibits tumor suppressor protein PTEN, miR-26a suppresses PTEN and increases AKT phosphorylation and nuclear factor kappaB (NFkappaB) activation, miR-31 represses tumor suppressor genes LATS2 and PPP2R2A, miR-205 is associated with cancer relapses, and miR-34c, a p53 target induced by DNA damage, suggests the involvement of p53 pathway in field carcinogenesis. Down-regulated let-7b leads to higher expression of CYP2J2 and decreased miR-126 enhances adhesion, migration and invasion through increased Crk protein. Further gene expression and pathway analyses will corroborate the relationship between miRNAs and predicted pathways in real time. Conclusion: We discovered a profile of miRNAs in the contralateral lung of patients with lung cancer as biomarkers of field cancerization in smokers with lung adenocarcinoma. Further knowledge of field cancerization may lead to better understanding of tumorigenesis and development of biomarkers for early lung cancer detection

BACKGROUND: Tuberculosis (TB) causes 1.45 million deaths annually world wide, the majority of which occur in the developing world. Active TB disease represents immune failure to control latent infection from airborne spread. Acid-fast bacillus (AFB) seen on sputum smear is a biomarker for contagiousness. METHODS: We enrolled 73 tuberculosis patients with extensive infiltrates into a research study using bronchoalveolar lavage (BAL) to sample lung immune cells and assay BAL cell cytokine production. All patients had sputum culture demonstrating Mycobacterium tuberculosis and 59/73 (81%) had AFB identified by microscopy of the sputum. Compared with smear negative patients, smear positive patients at presentation had a higher proportion with smoking history, a higher proportion with temperature >38.5(0) C, higher BAL cells/ml, lower percent lymphocytes in BAL, higher IL-4 and IL-12p40 in BAL cell supernatants. There was no correlation between AFB smear and other BAL or serum cytokines. Increasing IL-4 was associated with BAL PMN and negatively associated with BAL lymphocytes. Each 10-fold increase in BAL IL-4 and IL-12p40 increased the odds of AFB smear positivity by 7.4 and 2.2-fold, respectively, in a multi-variable logistic model. CONCLUSION: Increasing IL-4 and IL-12p40 production by BAL cells are biomarkers for AFB in sputum of patients who present with radiographically advanced TB. They likely reflect less effective immune control of pathways for controlling TB, leading to patients with increased infectiousness.

Lung cancer is the leading cause of cancer deaths worldwide largely owing to diagnosis of the disease at an advanced stage. Recent advances in blood-based biomarker research have the potential to reduce mortality by providing a means for detecting lung cancer at an earlier stage. Since the publication of the National Lung Cancer Screening Trial demonstrating reduction in mortality with computed tomography (CT) scan screening, the U.S. Preventive Services Task Force has released a draft statement recommending annual low-dose CT scan screening for high-risk patients. However, CT screening has a high false-positive rate leading to the need for additional imaging and invasive procedures. In this article, we review recent literature on blood-based lung cancer biomarkers that we believe will have a significant role in enhancing screening efficacy in the near future.

The objective of this study is to assess the impact on nodule detection and efficiency using a computer-aided detection (CAD) device seamlessly integrated into a commercially available picture archiving and communication system (PACS). Forty-eight consecutive low-dose thoracic computed tomography studies were retrospectively included from an ongoing multi-institutional screening study. CAD results were sent to PACS as a separate image series for each study. Five fellowship-trained thoracic radiologists interpreted each case first on contiguous 5 mm sections, then evaluated the CAD output series (with CAD marks on corresponding axial sections). The standard of reference was based on three-reader agreement with expert adjudication. The time to interpret CAD marking was automatically recorded. A total of 134 true-positive nodules, measuring 3 mm and larger were included in our study; with 85 >/= 4 and 50 >/= 5 mm in size. Readers detection improved significantly in each size category when using CAD, respectively, from 44 to 57 % for >/=3 mm, 48 to 61 % for >/=4 mm, and 44 to 60 % for >/=5 mm. CAD stand-alone sensitivity was 65, 68, and 66 % for nodules >/=3, >/=4, and >/=5 mm, respectively, with CAD significantly increasing the false positives for two readers only. The average time to interpret and annotate a CAD mark was 15.1 s, after localizing it in the original image series. The integration of CAD into PACS increases reader sensitivity with minimal impact on interpretation time and supports such implementation into daily clinical practice.

There is an unmet need for circulating biomarkers that can detect early-stage lung cancer. Here we show that a variant form of the nuclear matrix-associated DNA replication factor Ciz1 is present in 34/35 lung tumors but not in adjacent tissue, giving rise to stable protein quantifiable by Western blot in less than a microliter of plasma from lung cancer patients. In two independent sets, with 170 and 160 samples, respectively, variant Ciz1 correctly identified patients who had stage 1 lung cancer with clinically useful accuracy. For set 1, mean variant Ciz1 level in individuals without diagnosed tumors established a threshold that correctly classified 98% of small cell lung cancers (SCLC) and non-SCLC patients [receiver operator characteristic area under the curve (AUC) 0.958]. Within set 2, comparison of patients with stage 1 non-SCLC with asymptomatic age-matched smokers or individuals with benign lung nodules correctly classified 95% of patients (AUCs 0.913 and 0.905), with overall specificity of 76% and 71%, respectively. Moreover, using the mean of controls in set 1, we achieved 95% sensitivity among patients with stage 1 non-SCLC patients in set 2 with 74% specificity, demonstrating the robustness of the classification. RNAi-mediated selective depletion of variant Ciz1 is sufficient to restrain the growth of tumor cells that express it, identifying variant Ciz1 as a functionally relevant driver of cell proliferation in vitro and in vivo. The data show that variant Ciz1 is a strong candidate for a cancer-specific single marker capable of identifying early-stage lung cancer within at-risk groups without resort to invasive procedures.

It is currently not known whether most lung cancers detected by computerized tomography (CT) screening are aggressive and likely to be fatal if left untreated, or if a sizable fraction are indolent and unlikely to cause death during the natural lifetime of the individual. We developed a longitudinal biologically-based model of the relationship between individual smoking histories and the probability for lung cancer incidence, CT screen detection, lung cancer mortality, and other-cause mortality. The longitudinal model relates these different outcomes to an underlying lung cancer disease pathway and an effective other-cause mortality pathway, which are both influenced by the individual smoking history. The longitudinal analysis provides additional information over that available if these outcomes were analyzed separately, including testing if the number of CT detected and histologically-confirmed lung cancers is consistent with the expected number of lung cancers "in the pipeline". We assume indolent nodules undergo Gompertz growth and are detectable by CT, but do not grow large enough to contribute significantly to symptom-based lung cancer incidence or mortality. Likelihood-based model calibration was done jointly to data from 6878 heavy smokers without asbestos exposure in the control (placebo) arm of the Carotene and Retinol Efficacy Trial (CARET); and to 3,642 heavy smokers with comparable smoking histories in the Pittsburgh Lung Screening Study (PLuSS), a single-arm prospective trial of low-dose spiral CT screening for diagnosis of lung cancer. Model calibration was checked using data from two other single-arm prospective CT screening trials, the New York University Lung Cancer Biomarker Center (NYU) (n=1,021), and Moffitt Cancer Center (Moffitt) cohorts (n=677). In the PLuSS cohort, we estimate that at the end of year 2, after the baseline and first annual CT exam, that 33.0 (26.9, 36.9)% of diagnosed lung cancers among females and 7.0 (4.9,11.7)% among males were overdiagnosed due to being indolent cancers. At the end of the PLuSS study, with maximum follow-up of 5.8years, we estimate that due to early detection by CT and limited follow-up, an additional 2.2 (2.0,2.4)% of all diagnosed cancers among females and 7.1 (6.7,8.0)% among males would not have been diagnosed in the absence of CT screening. We also find a higher apparent cure rate for lung cancer among CARET females than males, consistent with the larger indolent fraction of CT detected and histologically confirmed lung cancers among PLuSS females. This suggests that there are significant gender differences in the aggressiveness of lung cancer. Females may have an inherently higher proportion of indolent lung cancers than males, or aggressive lung cancers may be brought into check by the immune system more frequently among females than males.

BACKGROUND: Exposure to ozone has been associated with adverse health effects, including premature mortality and cardiopulmonary and respiratory morbidity. In 2008, the U.S. Environmental Protection Agency (EPA) lowered the primary (health-based) National Ambient Air Quality Standard (NAAQS) for ozone to 75 ppb, expressed as the fourth-highest daily maximum 8-hr average over a 24-hr period. Based on recent monitoring data, U.S. ozone levels still exceed this standard in numerous locations, resulting in avoidable adverse health consequences. OBJECTIVES: We sought to quantify the potential human health benefits from achieving the current primary NAAQS standard of 75 ppb and two alternative standard levels, 70 and 60 ppb, which represent the range recommended by the U.S. EPA Clean Air Scientific Advisory Committee (CASAC). METHODS: We applied health impact assessment methodology to estimate numbers of deaths and other adverse health outcomes that would have been avoided during 2005, 2006, and 2007 if the current (or lower) NAAQS ozone standards had been met. Estimated reductions in ozone concentrations were interpolated according to geographic area and year, and concentration-response functions were obtained or derived from the epidemiological literature. RESULTS: We estimated that annual numbers of avoided ozone-related premature deaths would have ranged from 1,410 to 2,480 at 75 ppb to 2,450 to 4,130 at 70 ppb, and 5,210 to 7,990 at 60 ppb. Acute respiratory symptoms would have been reduced by 3 million cases and school-loss days by 1 million cases annually if the current 75-ppb standard had been attained. Substantially greater health benefits would have resulted if the CASAC-recommended range of standards (70-60 ppb) had been met. CONCLUSIONS: Attaining a more stringent primary ozone standard would significantly reduce ozone-related premature mortality and morbidity.