Faculty Bibliography

RATIONALE: Identification and characterization of asthma phenotypes are challenging due to disease complexity and heterogeneity. The Severe Asthma Research Program (SARP) used unsupervised cluster analysis to define 5 phenotypically distinct asthma clusters that they replicated using 3 variables in a simplified algorithm. We evaluated whether this simplified SARP algorithm could be used in a separate and diverse urban asthma population to recreate these 5 phenotypic clusters. METHODS: The SARP simplified algorithm was applied to adults with asthma recruited to the New York University/Bellevue Asthma Registry (NYUBAR) to classify patients into five groups. The clinical phenotypes were summarized and compared. RESULTS: Asthma subjects in NYUBAR (n = 471) were predominantly women (70%) and Hispanic (57%), which were demographically different from the SARP population. The clinical phenotypes of the five groups generated by the simplified SARP algorithm were distinct across groups and distributed similarly to those described for the SARP population. Groups 1 and 2 (6 and 63%, respectively) had predominantly childhood onset atopic asthma. Groups 4 and 5 (20%) were older, with the longest duration of asthma, increased symptoms and exacerbations. Group 4 subjects were the most atopic and had the highest peripheral eosinophils. Group 3 (10%) had the least atopy, but included older obese women with adult-onset asthma, and increased exacerbations. CONCLUSIONS: Application of the simplified SARP algorithm to the NYUBAR yielded groups that were phenotypically distinct and useful to characterize disease heterogeneity. Differences across NYUBAR groups support phenotypic variation and support the use of the simplified SARP algorithm for classification of asthma phenotypes in future prospective studies to investigate treatment and outcome differences between these distinct groups. TRIAL REGISTRATION: Clinicaltrials.gov NCT00212537.

A promising strategy for cancer immunotherapy is to disrupt key pathways regulating immune tolerance, such as cytotoxic T lymphocyte-associated protein 4 (CTLA-4). However, the determinants of response to anti-CTLA-4 mAb treatment remain incompletely understood. In murine models, anti-CTLA-4 mAbs alone fail to induce effective immune responses to poorly immunogenic tumors but are successful when combined with additional interventions, including local ionizing radiation (IR) therapy. We employed an established model based on control of a mouse carcinoma cell line to study endogenous tumor-infiltrating CD8+ T lymphocytes (TILs) following treatment with the anti-CTLA-4 mAb 9H10. Alone, 9H10 monotherapy reversed the arrest of TILs with carcinoma cells in vivo. In contrast, the combination of 9H10 and IR restored MHC class I-dependent arrest. After implantation, the carcinoma cells had reduced expression of retinoic acid early inducible-1 (RAE-1), a ligand for natural killer cell group 2D (NKG2D) receptor. We found that RAE-1 expression was induced by IR in vivo and that anti-NKG2D mAb blocked the TIL arrest induced by IR/9H10 combination therapy. These results demonstrate that anti-CTLA-4 mAb therapy induces motility of TIL and that NKG2D ligation offsets this effect to enhance TILs arrest and antitumor activity.

The authors conducted a cross-sectional study to assess the relation between arsenic exposure from drinking water and plasma levels of markers of systemic inflammation and endothelial dysfunction (matrix metalloproteinase-9, myeloperoxidase, plasminogen activator inhibitor-1, soluble E-selectin, soluble intercellular adhesion molecule-1 (ICAM-1), and soluble vascular adhesion molecule-1 (VCAM-1)) using baseline data from 668 participants (age, >30 years) in the Health Effects of Arsenic Longitudinal Study in Bangladesh (2007-2008). Both well water arsenic and urinary arsenic were positively associated with plasma levels of soluble VCAM-1. For every 1-unit increase in log-transformed well water arsenic (ln mug/L) and urinary arsenic (ln mug/g creatinine), plasma soluble VCAM-1 was 1.02 (95% confidence interval: 1.01, 1.03) and 1.04 (95% confidence interval: 1.01, 1.07) times greater, respectively. There was a significant interaction between arsenic exposure and higher body mass index, such that the increased levels of plasminogen activator inhibitor-1 and soluble VCAM-1 associated with arsenic exposure were stronger among people with higher body mass index. The findings indicate an effect of chronic arsenic exposure from drinking water on vascular inflammation and endothelial dysfunction that could be modified by body mass index and also suggest a potential mechanism underlying the association between arsenic exposure and cardiovascular disease.

ABSTRACT: INTRODUCTION: Prospective epidemiologic studies have consistently shown that levels of circulating androgens in postmenopausal women are positively associated with breast cancer risk. However, data in premenopausal women are limited. METHODS: A case-control study nested within the NYU Women's Health Study was conducted. A total of 356 cases (276 invasive and 80 in situ) and 683 individually-matched controls were included. Matching variables included age and date, phase, and day of menstrual cycle at blood donation. Testosterone, androstenedione, dehydroandrosterone sulfate (DHEAS) and sex hormone-binding globulin (SHBG) were measured using direct immunoassays. Free testosterone was calculated. RESULTS: Premenopausal serum testosterone and free testosterone concentrations were positively associated with breast cancer risk. In models adjusted for known risk factors of breast cancer, the odds ratios for increasing quintiles of testosterone were 1.0 (reference), 1.5 (95% confidence interval (CI) , 0.9-2.3), 1.2 (95% CI, 0.7-1.9), 1.4 (95% CI, 0.9-2.3) and 1.8 (95% CI, 1.1-2.9; Ptrend = 0.04), and for free testosterone were 1.0 (reference), 1.2 (95% CI, 0.7-1.8), 1.5 (95% CI, 0.9- 2.3), 1.5 (95% CI, 0.9-2.3), 1.8 (95% CI, 1.1-2.8, Ptrend = 0.01). A marginally significant positive association was observed with androstenedione (p = 0.07), but no association with DHEAS or SHBG. Results were consistent in analyses stratified by tumor type (invasive, in situ), estrogen receptor status, age at blood donation, and menopausal status at diagnosis. Intra-class correlation coefficients for samples collected from 0.8 to 5.3 years apart (median 2 years) in 138 cases and 268 controls were greater than 0.7 for all biomarkers except for androstenedione (0.57 in controls). CONCLUSIONS: Premenopausal concentrations of testosterone and free testosterone are associated with breast cancer risk. Testosterone and free testosterone measurements are also highly reliable (i.e. a single measurement is reflective of a woman's average level over time). Results from other prospective studies are consistent with our results. The impact of including testosterone or free testosterone to breast cancer risk prediction models for women between the ages of 40 and 50 should be assessed. Improving risk prediction models for this age group could help decision making regarding both screening and chemoprevention of breast cancer.

We propose a marginalized joint-modeling approach for marginal inference on the association between longitudinal responses and covariates when longitudinal measurements are subject to informative dropouts. The proposed model is motivated by the idea of linking longitudinal responses and dropout times by latent variables while focusing on marginal inferences. We develop a simple inference procedure based on a series of estimating equations, and the resulting estimators are consistent and asymptotically normal with a sandwich-type covariance matrix ready to be estimated by the usual plug-in rule. The performance of our approach is evaluated through simulations and illustrated with a renal disease data application

Nested case-control (NCC) sampling is widely used in large epidemiological cohort studies for its cost effectiveness, but its data analysis primarily relies on the Cox proportional hazards model. In this paper, we consider a family of linear transformation models for analyzing NCC data and propose an inverse selection probability weighted estimating equation method for inference. Consistency and asymptotic normality of our estimators for regression coefficients are established. We show that the asymptotic variance has a closed analytic form and can be easily estimated. Numerical studies are conducted to support the theory and an application to the Wilms' Tumor Study is also given to illustrate the methodology

PURPOSE: Chemoradiation after surgery for locally advanced gastric cancer improves overall and relapse-free survival compared with observation. However, locoregional recurrences remain high. Accordingly, we instituted this pilot/feasibility study, including intraperitoneal 5-fluoro-2'-deoxyuridine (IP FUDR) as part of the treatment. METHODS: Gastric/gastroesophageal junction adenocarcinoma stage Ib-IV (M0) patients who underwent R(0) resection were eligible and had IP catheters inserted at time of surgery. IP FUDR (3 g/dose/day) was given during study days 1-3 and 15-17 before combined 5-fluorouracil, leucovorin, and external beam radiation (45 Gy). Endpoints included toxicity, completion rate, locoregional recurrence, and survival. RESULTS: Twenty-eight patients (22 men) were enrolled from 2002-2006 at two institutions; their median age was 59.5 years. After R(0) resection, a median 22 (range, 8-102) lymph nodes were examined, and 22 patients had positive nodes. AJCC stages were IB (n = 8), II (n = 10), IIIA (n = 5), IIIB (n = 1), and IV (n = 4). Full-dose IP FUDR and chemoradiation treatment was completed in 20 and 25 patients, respectively. At nearly 4-year median follow-up, 11 patients were disease-free, 5 were alive with disease, 7 were dead of disease, and 1 was dead from other cause; 4 have been lost to follow-up. Recurrences were local in one, intra-abdominal in six, distant in two, multiple sites in two, and unknown in one. The median relapse-free survival is 65.3 months, and the median overall survival has not yet been reached. CONCLUSIONS: IP FUDR before chemoradiation after R(0) gastric cancer resection is well tolerated without compromising completion of postoperative adjuvant treatment. Larger randomized trials studying IP FUDR as part of gastric cancer multidisciplinary treatment are needed to prove efficacy in reducing regional recurrence and improving survival