Faculty Bibliography

PURPOSE: World Trade Center (WTC) exposure caused airflow obstruction years after exposure. Chitinases and IgE are innate and humoral mediators of obstructive airway disease. We investigated if serum expression of chitinases and IgE early after WTC exposure predicts subsequent obstruction. METHODS: With a nested case-control design, 251 FDNY personnel had chitotriosidase, YKL-40 and IgE measured in serum drawn within months of 9/11/2001. The main outcome was subsequent Forced Expiratory Volume after 1 second/Forced Vital Capacity (FEV1/FVC) less than the lower limit of normal (LLN). Cases (N = 125) had abnormal FEV1/FVC whereas controls had normal FEV1/FVC (N = 126). In a secondary analysis, resistant cases (N = 66) had FEV1 (>/=107 %) one standard deviation above the mean. Logistic regression adjusted for age, BMI, exposure intensity and post-exposure FEV1/FVC modeled the association between early biomarkers and later lung function. RESULTS: Cases and Controls initially lost lung function. Controls recovered to pre-9/11 FEV1 and FVC while cases continue to decline. Cases expressed lower serum chitotriosidase and higher IgE levels. Increase in IgE increased the odds of airflow obstruction and decreased the odds of above average FEV1. Alternately, increasing chitotriosidase decreased the odds of abnormal FEV1/FVC and increased the odds of FEV1 >/= 107 %. Serum YKL-40 was not associated with FEV1/FVC or FEV1 in this cohort. CONCLUSIONS: Increased serum chitotriosidase reduces the odds of developing obstruction after WTC-particulate matter exposure and is associated with recovery of lung function. Alternately, elevated IgE is a risk factor for airflow obstruction and progressive lung function decline.

Pulmonary vascular loss is an early feature of chronic obstructive pulmonary disease. Biomarkers of inflammation and of metabolic syndrome, predicts loss of lung function in World Trade Center Lung Injury(WTC-LI). We investigated if other cardiovascular disease (CVD) biomarkers also predicted WTC-LI.This nested case-cohort study used 801 never smoker, WTC exposed firefighters with normal pre-9/11 lung function presenting for subspecialty pulmonary evaluation (SPE) before March, 2008. A representative sub-cohort of 124/801 with serum drawn within six months of 9/11 defined CVD biomarker distribution. Post-9/11/01 FEV1 at subspecialty exam defined cases: susceptible WTC-LI cases with FEV1/=107% (68/801). All models were adjusted for WTC exposure intensity, BMI at SPE, age at 9/11, and pre-9/11 FEV1.Susceptible WTC-LI cases had higher levels of Apo-AII, CRP, and MIP-4 with significant RRs of 3.85, 3.93, and 0.26 respectively with an area under the curve (AUC) of 0.858. Resistant WTC-LI cases had significantly higher sVCAM and lower MPO with RRs of 2.24, and 2.89 respectively; AUC 0.830.Biomarkers of CVD in serum six-month post-9/11 predicted either susceptibility or resistance to WTC-LI. These biomarkers may define pathways producing or protecting subjects from pulmonary vascular disease and associated loss of lung function after an irritant exposure.

Rationale: An increased ratio of pulmonary artery to aorta (PA/A) diameter, as a marker of vascular injury, measured by computed tomography (CT) predicts future exacerbations in patients with chronic obstructive pulmonary disease (COPD) Wells et. al. NEJM. World Trade Center (WTC) exposed fire fighters have developed respiratory symptoms and a subset had a decline in pulmonary function. Our group has previously shown that systemic biomarkers of inflammation and cardiovascular disease predict this decline. We hypothesize that a PA/A ratio >/= to 1 will be associated with a decline in FEV1. Methods: From a baseline cohort of never smokers with normal spirometry pre 9/11, cases and controls were selected. Cases had FEV1 fall to less than the lower limit of normal (< LLN), and controls had preserved lung function, see figure 1. Spirometry was performed according to ATS/ERS guidelines. Inspiratory series CT images, collected contemporaneously with spirometry, were retrospectively assessed using iSite PACS, (Philips iSite Enterprise, Version 3.6.114; www.healthcare.philips.com). The diameter of the main PA at the level of its bifurcation and the diameter of the ascending aorta in its maximum dimension were recorded using the same image. ES, who was blinded to group assignment, made all measurements. Statistics and data management were performed using SPSS. Results: CT images were available for 91 patients in the case/control cohort. Body mass index (BMI), age, exposure and pulmonary function data are shown in Table 1. Exposure intensity, age at exposure, time from 9/11 to spirometry and to CT were similar. BMI was increased in cases compared to controls. The mean PA diameter and PA/A ratio were increased in cases (p=0.05, 0.09), the mean A diameter was similar. Using binary logistic regression the odds ratio of having an FEV1< LLN if the PA/A ratio was >/= 1 was 3.6 (p=0.047), when corrected for exposure, age at 9/11 and BMI. Conclusions: In this preliminary study a PA/A ratio >/= 1 was associated with WTC related decline in FEV1. There are several potential confounders. Data on the presence of congestive heart failure, sleep apnea and other comorbidities are presenting lacking. Additionally, patient effort and respiratory system compliance may influence inspiratory measurements of the PA. In future studies, we plan to analyze expiratory CT images and correlate with other markers of heart disease. Increased PA/A represents another potentially useful non-invasive tool to assess for obstructive lung dysfunction and warrants further study. (Table Presented)

BACKGROUND: The WTC collapse exposed over 300,000 people to high concentrations of WTC-PM; particulates up to approximately 50 mm were recovered from rescue workers' lungs. Elevated MDC and GM-CSF independently predicted subsequent lung injury in WTC-PM-exposed workers. Our hypotheses are that components of WTC dust strongly induce GM-CSF and MDC in AM; and that these two risk factors are in separate inflammatory pathways. METHODOLOGY/PRINCIPAL FINDINGS: Normal adherent AM from 15 subjects without WTC-exposure were incubated in media alone, LPS 40 ng/mL, or suspensions of WTC-PM(10-53) or WTC-PM(2.5) at concentrations of 10, 50 or 100 microg/mL for 24 hours; supernatants assayed for 39 chemokines/cytokines. In addition, sera from WTC-exposed subjects who developed lung injury were assayed for the same cytokines. In the in vitro studies, cytokines formed two clusters with GM-CSF and MDC as a result of PM(10-53) and PM(2.5). GM-CSF clustered with IL-6 and IL-12(p70) at baseline, after exposure to WTC-PM(10-53) and in sera of WTC dust-exposed subjects (n = 70) with WTC lung injury. Similarly, MDC clustered with GRO and MCP-1. WTC-PM(10-53) consistently induced more cytokine release than WTC-PM(2.5) at 100 microg/mL. Individual baseline expression correlated with WTC-PM-induced GM-CSF and MDC. CONCLUSIONS: WTC-PM(10-53) induced a stronger inflammatory response by human AM than WTC-PM(2.5). This large particle exposure may have contributed to the high incidence of lung injury in those exposed to particles at the WTC site. GM-CSF and MDC consistently cluster separately, suggesting a role for differential cytokine release in WTC-PM injury. Subject-specific response to WTC-PM may underlie individual susceptibility to lung injury after irritant dust exposure.

RATIONALE: Biomarkers of sepsis severity and mortality are an important area of investigation. Our group has shown that increased serum levels of soluble(s)CD28 and sCD40L are predictive of mortality from sepsis. This has more recently been validated by other groups. We hypothesize that the release of microparticles(MPs) bound to co-stimulatory molecules into the circulation is one of the causes of disseminated inflammation. The mechanism producing sCD28 and sCD40L is unknown. We have previously shown that MP activity is induced in murine sepsis. Our current work is focused on using flow-cytometry to identify the characteristics of MPs and determine if they express CD28 and CD40L in sepsis models. METHODS: in vivo: Polymicrobial sepsis was induced in C57BL/6 mice using 19-Gauge cecal ligation and puncture(CLP) and citrated plasma was collected by cardiac puncture 18 hours later. in vitro: RAW264.7 cells 2x106 cells/mL in a 6 well plate were exposed to LPS(40 ng/mL) or media alone and incubated overnight. MP Isolation: MP containing supernatants were centrifuged at 1,500gX15 min and ultracentrifugation at 70,000gX30 min. Flow Cytometric Analysis was performed to quantify MP populations in the in vivo and in vitro models (AccuriC6). Forward scatter(FSC) and side scatter(SSC) of light was set in logarithmic scale, and the threshold was set at the FSC parameter(FS=1). The fluorescence channels were also set at logarithmic gain. Standard fluorescent microbeads(1 mum) were used to set the MP gate. In order to distinguish true events from electronic noise and increase the specificity of microparticle detection, events in the MP gate were further discriminated by labeling with PE-Annexin-V. MP expression of CD28/CD40L was determined using APC-labeled CD28 and PerCP-labeled CD40L. RESULTS: MPs were imaged using TEM, Figure 1. MPs were identified and characterized using flow cytometry, Figure 2A-B. Plasma from operated septic mice had 2.5-fold greater Annexin-V+ MPs compared to unoperated non-septic controls, Figure 2C. Annexin-V+ MPs were 3.5-fold greater in RAW cells exposed to LPS as compared to control. We have observed MPs expressing CD28 and CD40L in the serum of septic mice. CONCLUSIONS: MP counts are higher in both in vivo and in vitro models of sepsis as compared to unoperated non-septic controls. Preliminary data shows that MPs may be carriers of biologically active CD28 and CD40L. Future experiments will further delineate inflammatory mediators expressed on the surface of MPs and their role in sepsis. (Figure Presented)