Faculty Bibliography

Biomarkers can be important predictors of disease severity and progression. The intense exposure to particulates and other toxins from the destruction of the World Trade Center (WTC) overwhelmed the lung's normal protective barriers. The Fire Department of New York (FDNY) cohort not only had baseline pre-exposure lung function measures but also had serum samples banked soon after their WTC exposure. This well-phenotyped group of highly exposed first responders is an ideal cohort for biomarker discovery and eventual validation. Disease progression was heterogeneous in this group in that some individuals subsequently developed abnormal lung function while others recovered. Airflow obstruction predominated in WTC-exposed patients who were symptomatic. Multiple independent disease pathways may cause this abnormal FEV1 after irritant exposure. WTC exposure activates one or more of these pathways causing abnormal FEV1 in an individual. Our hypothesis was that serum biomarkers expressed within 6 months after WTC exposure reflect active disease pathways and predict subsequent development or protection from abnormal FEV1 below the lower limit of normal known as WTC-Lung Injury (WTC-LI). We utilized a nested case-cohort control design of previously healthy never smokers who sought subspecialty pulmonary evaluation to explore predictive biomarkers of WTC-LI. We have identified biomarkers of inflammation, metabolic derangement, protease/antiprotease balance, and vascular injury expressed in serum within 6 months of WTC exposure that were predictive of their FEV1 up to 7 years after their WTC exposure. Predicting future risk of airway injury after particulate exposures can focus monitoring and early treatment on a subset of patients in greatest need of these services.

BACKGROUND: Noninvasive sputum sampling has enabled the identification of biomarkers in asthmatic patients. Studies of discrete cell populations in sputum can enhance measurements compared with whole sputum in which changes in rare cells and cell-cell interactions can be masked. OBJECTIVE: We sought to enrich for sputum-derived human bronchial epithelial cells (sHBECs) and sputum-derived myeloid type 1 dendritic cells (sDCs) to describe transcriptional coexpression of targets associated with a type 2 immune response. METHODS: A case-control study was conducted with patients with mild asthma (asthmatic cases) and healthy control subjects. Induced sputum was obtained for simultaneous enrichment of sHBECs and sDCs by using flow cytometry. Quantitative PCR was used to measure mRNA for sHBEC thymic stromal lymphopoietin (TSLP), IL33, POSTN, and IL25 and downstream targets in sDCs (OX40 ligand [OX40L], CCL17, PPP1R14A, CD1E, CD1b, CD80, and CD86). RESULTS: Final analyses for the study sample were based on 11 control subjects and 13 asthmatic cases. Expression of TSLP, IL33, and POSTN mRNA was increased in sHBECs in asthmatic cases (P = .001, P = .05, and P = .04, respectively). Expression of sDC OX40L and CCL17 mRNA was increased in asthmatic cases (P = .003 and P = .0001, respectively). sHBEC TSLP mRNA expression was strongly associated with sDC OX40L mRNA expression (R = 0.65, P = .001) and less strongly with sDC CCL17 mRNA expression. sHBEC IL33 mRNA expression was associated with sDC OX40L mRNA expression (R = 0.42, P = .04) but not sDC CCL17 mRNA expression. CONCLUSIONS: Noninvasive sampling and enrichment of select cell populations from sputum can further our understanding of cell-cell interactions in asthmatic patients with the potential to enhance endotyping of asthmatic patients.

Abstract Objective: To identify key factors associated with poor asthma control among adults in the World Trade Center (WTC) Health Registry, a longitudinal study of rescue/recovery workers and community members who were directly exposed to the 2001 WTC terrorist attacks and their aftermath. Methods: We studied incident asthma diagnosed by a physician during 9/12/2001- 12/31/2003 among participants aged >18 on 9/11/2001, as reported on an enrollment (2003-2004) or follow-up questionnaire. Based on modified National Asthma Education and Prevention Program criteria, asthma was considered controlled, poorly-controlled, or very poorly-controlled at the time of a 2011-2012 follow-up questionnaire. Probable post-traumatic stress disorder, depression, and generalized anxiety disorder were defined using validated scales. Self-reported gastroesophageal reflux symptoms (GERS) and obstructive sleep apnea (OSA) were obtained from questionnaire responses. Multinomial logistic regression was used to examine factors associated with poor or very poor asthma control. Results: Among 2 445 participants, 33.7% had poorly-controlled symptoms and 34.6% had very poorly-controlled symptoms in 2011-12. Accounting for factors including age, education, body mass index, and smoking, there was a dose-response relationship between the number of mental health conditions and poorer asthma control. Participants with three mental health conditions had five times the odds of poor control and thirteen times the odds of very poor control compared to participants without mental health comorbidities. GERS and OSA were significantly associated with poor or very poor control. Conclusions: Rates of poor asthma control were very high in this group with post-9/11 diagnosed asthma. Comprehensive care of 9/11-related asthma should include management of mental and physical health comorbidities.

INTRODUCTION: Impulse oscillometry (IOS) has been used to demonstrate distal airway dysfunction in symptomatic WTC exposed patients despite normal spirometry. However, it remains to be determined whether the respiratory symptoms can be attributed to the observed functional abnormalities. The present study was designed to assess the simultaneous relationship between the onset of respiratory symptoms and IOS abnormalities in patients undergoing bronchoprovocation for diagnostic evaluation. METHODS: Methacholine challenge testing (MCT) was performed in 113 symptomatic WTC dust exposed patients with normal spirometry that were enrolled WTC Environmental Health Center treatment program. In addition to spirometry, the MCT protocol included performance of IOS and assessment of respiratory symptoms (cough, dyspnea, chest tightness). IOS parameters included resistance at 5 and 20Hz (R⁵ and R₂₀) and frequency dependence of resistance assessed as the difference between these parameters (R_5-20). The PC20 for FEV₁, was used to categorize bronchial hyperreactivity (BHR) as negative (>16mg/ml), borderline (4-16mg/ml) or positive (<4mg/ml). RESULTS: The cohort was 58% female with mean age 49+/-12yr and BMI 29+/-5 kg/m². Baseline spirometry was within normal limits (FEV₁ 98+/-13% predicted, FEV₁/FVC 80+/-4%). Approximately 58% demonstrated abnormal baseline R₅ or R_5-20 indicating respiratory dysfunction despite normal spirometry. MCT revealed BHR, as assessed by spirometry, in 49/113 patients (43%). An additional 27 patients became symptomatic at methacholine doses <4mg/ml despite minimal change in FEV₁ (<5% decrement). All of these patients demonstrated increased R₅, R₂₀ and R_5-20 that coincided with onset of symptoms; median (IQR) increases were 23% (16-41), 13% (7-20), and 92% (39-138), respectively. Following bronchodilator administration, respiratory symptoms resolved and IOS parameters returned towards baseline. CONCLUSIONS: During bronchoprovocation, development of symptoms may coincide with development of distal airway dysfunction as assessed by IOS, even in absence of change in FEV₁. Findings reversed with bronchodilator administration reinforcing the link between symptoms and distal airway dysfunction

Pulmonary hypertension has a marked detrimental effect on quality of life and life expectancy. In a mouse model of antigen-induced pulmonary arterial remodeling, we have recently shown that coexposure to urban ambient particulate matter (PM) significantly increased the thickening of the pulmonary arteries and also resulted in significantly increased right ventricular systolic pressures. Here we interrogate the mechanism and show that combined neutralization of interleukin 13 (IL-13) and IL-17A significantly ameliorated the increase in right ventricular systolic pressure, the circumferential muscularization of pulmonary arteries, and the molecular change in the right ventricle. Surprisingly, our data revealed a protective role of IL-17A for the antigen- and PM-induced severe thickening of pulmonary arteries. This protection was due to the inhibition of the effects of IL-13, which drove this response, and the expression of metalloelastase and resistin-like molecule alpha. However, the latter was redundant for the arterial thickening response. Anti-IL-13 exacerbated airway neutrophilia, which was due to a resulting excess effect of IL-17A, confirming concurrent cross inhibition of IL-13- and IL-17A-dependent responses in the lungs of animals exposed to antigen and PM. Our experiments also identified IL-13/IL-17A-independent molecular reprogramming in the lungs induced by exposure to antigen and PM, which indicates a risk for arterial remodeling and protection from arterial constriction. Our study points to IL-13- and IL-17A-coinduced inflammation as a new template for biomarkers and therapeutic targeting for the management of immune response-induced pulmonary hypertension.

Particulates from air pollution are implicated in causing or exacerbating respiratory and systemic cardiovascular diseases and are thought to be among the leading causes of morbidity and mortality. However, the contribution of ambient particulate matter to diseases affecting the pulmonary circulation, the right heart, and especially pulmonary hypertension is much less documented. Our own work and that of other groups has demonstrated that prolonged exposure to antigens via the airways can cause severe pulmonary arterial remodeling. In addition, vascular changes have been well documented in a typical disease of the airways, asthma. These experimental and clinical findings link responses in the airways with responses in the lung's vasculature. It follows that particulate air pollution could cause, or exacerbate, diseases in the pulmonary circulation and associated pulmonary hypertension. This perspective details the literature for support of this concept. Data regarding the health effects of particulate matter from air pollution on the lung's vasculature, with emphasis on the lung's inflammatory responses to particulate matter deposition and pulmonary hypertension, are discussed. A deeper understanding of the health implications of exposure to ambient particulate matter will improve our knowledge of how to improve the management of lung diseases, including diseases of the pulmonary circulation. As man-made ambient particulate air pollution is typically linked to economic growth, a better understanding of the health effects of exposure to particulate air pollution is expected to integrate the global goal of achieving healthy living for all.

Pulmonary Hypertension is characterized by pulmonary arterial remodeling and increased pressure in the pulmonary circulation. It is often associated with inflammation in the lungs and can lead to right heart failure. Our work shows that urban ambient pollution exacerbates the experimental pulmonary hypertension phenotype just like other types of inflammatory lung conditions. We aimed to identify microRNAs (miRNAs) that are differentially expressed in our mouse model. In addition, we examined plasma samples from individuals occupationally exposed to high levels of air pollution or cigarette smoke, and from controls. Our study is the first to show significantly de-regulated expression of three microRNA species (miR-135a, miR-21, miR-204) in the lungs of mice that were exposed to antigen and particulate matter and developed pulmonary hypertension. De-regulated levels of miR-21 and miR-204 have been reported in human pulmonary hypertension and in experimental pulmonary hypertension. MiR-135a is targeting STAT6 and upregulated expression has been reported in experimental asthma. Using human samples, our study showed that plasma levels of miR-21 and miR-135a, but not levels of miR-204, clustered individuals with high dose exposures and individuals with low dose environmental exposures. Current studies are aimed at identifying the cytokines that control these miRNAs' expression. The long range goal is to identify miRNAs that indicate an at-risk state of the pulmonary vasculature

INTRODUCTION: We have previously shown improvement in spirometry parameters in symptomatic WTC dust exposed community members enrolled in the WTC Environmental Health Center treatment program. Additionally, impulse oscillometry (IOS) has demonstrated evidence for distal lung injury not apparent on spirometry. We hypothesize that longitudinal change of spirometry will differ based on presence or absence of distal airway injury and its response to bronchodilator at baseline. METHODS: 810 patients were identified with more than one spirometry and IOS assessment. IOS parameters included resistance at 5 and 20Hz (R₅ and R₂₀) and frequency dependence of resistance assessed as the difference between these parameters (R_5-20). Linear mixed effects modeling evaluated longitudinal changes in IOS parameters, FVC and FEV₁ for the entire population. Separate models were fit for subgroups categorized based on normal vs. abnormal baseline spirometry and normal vs. abnormal baseline IOS (R₅>3.96 cmH2O/L/s). Analyses were adjusted for confounding factors (age, gender, BMI, race/ethnicity, smoking, exposure category and dust cloud exposure). RESULTS: Mean age was 50yr. Patients were mostly female (52%) and had diverse race/ethnicity. At baseline, mean FVC was 91+/-17% predicted and FEV₁ was 88+/-18% predicted. A normal spirometry pattern was noted in the majority (67%; n=542). Despite normal spirometry, IOS revealed abnormalities in 67% (n=364). Longitudinal analysis of IOS parameters (R₅, R₂₀, R_5-20) over time revealed no significant trends for the entire population and for subgroups categorized by baseline spirometry pattern. In contrast, the longitudinal change in spirometry variables differed based on presence of IOS abnormality. In patients with normal spirometry, FEV₁ increased more rapidly in patients with abnormal baseline IOS compared to those with normal IOS (0.76 vs. 0.52 % predicted/yr; Table 1). For patients with abnormal baseline spirometry, FVC increased more rapidly in the abnormal vs. normal IOS patients (1.73 vs. 1.02 % predicted/yr). Patients with IOS response to bronchodilator (highest quartile for improvement of R₅ post bronchodilator) demonstrated a more rapid longitudinal increase in FEV₁ compared with patients without bronchodilator response (lowest quartile)(0.88 vs. 0.53 % predicted/yr,; Table 2). CONCLUSIONS: Spirometry parameters demonstrated improvement over time, while improvement in IOS parameters was not evident, suggesting potential irreversible injury in the distal lung. However, assessment of baseline distal airway function and its acute response to bronchodilator predicted longitudinal response of spirometry in patients enrolled in a treatment program. (Table Presented)

Rationale: Exposure to World Trade Center (WTC) dust and fumes is associated with onset of asthma-like respiratory symptoms in exposed community members including local workers, residents and clean-up workers. Although abnormal spirometry measurements are often not detected in these patients, impulse oscillometry (IOS) suggests abnormalities localized to the smaller airways. Peripheral C-reactive protein (CRP) is a marker of systemic inflammation. Since an association between CRP and asthma has been reported, we hypothesized that levels of CRP would be associated with lung function abnormalities as assessed by spirometry and IOS measurements in community members exposed to WTC dust/fumes and gasses. Methods: The WTC Environmental Health Center (EHC) is a treatment program for community members, with presumed WTC-related symptoms. Patients undergo a standardized evaluation including questionnaires and routine blood work, spirometry and IOS measurements. Between 10/1/2009 and 9/29/2011, a measurement of CRP was included for patients undergoing standardized visits. Measurements of lung function were compared utilizing the Wilcoxon test between subjects with normal vs. elevated CRP and further analyzed using linear regression models with log(CRP) as a continuous predictor. Regression analyses were adjusted for potential confounding factors including Body mass index (BMI), exposure category, and smoking history. Results: 208 WTC-exposed individuals met inclusion criteria. Valid spirometry and IOS data were available in 204 and 189 patients, respectively. Mean age was 49 years, 53% were female. Exposure categories (local workers, clean-up workers, residents) were associated with normal/elevated CRP levels (P=0.01). Smokers had a larger portion of elevated CRP (P=0.048). BMI was higher among the high CRP group (Wilcoxon test, P<0.001). FEV₁ and FVC were lower for the high CRP group (P=0.016, P=0.033). However, CRP level was not associated with the ratio FEV₁/FVC (P=0.58). The IOS measurements (R₅, R_5-20, AX ) were higher (P=0.01, P=0.003, P=.001, respectively) among the high CRP group. Multiple regression analysis confirmed that log(CRP) values were inversely correlated with % of predicted FEV 1 (P=0.009) and positively correlated with log(R₅) (P=0.02) and log(AX) (P=0.0045) after adjustment for log(BMI). Conclusions: Peripheral CRP was negatively correlated with levels of FEV₁ and positively correlated with IOS measurements in community members with WTC dust/gas/fume exposure. These data suggest a relationship between systemic inflammation, as reflected by CRP, and both large and small airway abnormalities in a WTC- exposed population

Rationale: Asthma is a chronic inflammatory disease of the airway influenced by genetic variants, environmental factors, and their interactions. Variants of the interleukin-1 receptor antagonist (IL1RN) gene, encoding an anti-inflammatory cytokine, are associated with asthma. We investigated the gene-environment interactions of childhood environmental tobacco smoke (ETS) exposure with IL1RN genotypes of single-nucleotide polymorphisms (SNPs) for asthma susceptibility in an urban adult population. Methods: DNA samples from the NYU/Bellevue Asthma Registry (NYUBAR) were genotyped for six tag SNPs in IL1RN in 259 asthma cases and 182 unrelated healthy controls. Information about childhood ETS exposure and age at onset for doctor diagnosed asthma were collected. Logistic regression was used to assess associations of IL1RN variants (alleles, genotypes, haplotypes) with asthma, adjusting for population admixture and other factors and covariates. Gene-environment interactions (GEIs) for the risk of asthma and early onset asthma were evaluated via stratification on childhood ETS exposure (with/without) and on IL1RN SNP genotypes (rare/common), respectively. Visible patterns of GEIs were displayed using stratified Kaplan-Meier curves for age of asthma onset. Results: Allelic and genotypic association analyses of the IL1RN tag SNPs and asthma susceptibility for the NYUBAR population as a whole resulted in findings that were in accordance with previous publications with protective effects of rare genotypes of candidate SNPs. Stratified analyses based on ETS exposure status indicated that the protective effects of rare genotypes of tag SNPs (e.g. GG in SNP rs392503) were significant only within the groups without childhood ETS exposure (OR=0.179, P=0.009); in contrast, there was a significantly elevated risk for early onset asthma among rare-genotype carriers with ETS exposure (OR=4.02, P=0.019). Importantly, whereas childhood ETS exposure was a risk factor for early onset asthma across all genotype groups of IL1RN (OR=1.74, P=0.03), it dramatically increased the risk within the group carrying rare SNP genotypes of IL1RN with the observed odds ratios (ORs) in the range between 7.3 and 9.1 (Fisher exact P-values<0.05). Conclusion: Analysis of gene-environment interactions between ETS exposure and IL1RN variants indicated that, at population level, childhood ETS exposure disrupted the protective effect of rare tag SNP genotypes of IL1RN for asthma and turned them into high risk genotypes for early onset asthma