Faculty Bibliography

INTRODUCTION: Small airway dysfunction occurs following WTC dust exposure, but its role in producing symptoms is unclear. METHODS: Methacholine challenge (MCT) was used to assess the relationship between onset of respiratory symptoms and small airway abnormalities in 166 symptomatic WTC dust-exposed patients. Forced oscillation testing (FOT) and respiratory symptoms were assessed during MCT. FOT parameters included resistance at 5 and 20 Hz (R5 and R20 ) and the R5 minus R20 (R5-20 ). RESULTS: Baseline spirometry was normal in all (mean FEV1 100 + 13% predicted, mean FEV1 /FVC 80 + 4%). MCT revealed bronchial hyperreactivity by spirometry in 67 patients. An additional 24 patients became symptomatic despite minimal FEV1 change (<5%); symptom onset coincided with increased R5 and R5-20 (P > 0.001 vs. baseline). The dose-response of FOT (reactivity) was greater compared with subjects that remained asymptomatic (P < 0.05). CONCLUSIONS: FOT during MCT uncovered reactivity in small airways as a mechanism for respiratory symptoms in subjects with inhalational lung injury. Am. J. Ind. Med. 59:767-776, 2016. (c) 2016 Wiley Periodicals, Inc.

OBJECTIVE: Longitudinal assessment of lower respiratory symptoms (LRS) in community members with World Trade Center (WTC) exposures. METHODS: Adult members of a treatment program with complete standardized visits were evaluated (n = 798). Association of demographic characteristics, mental health symptoms and lung function with trajectory of LRS between initial and monitoring visit was evaluated. RESULTS: Severe LRS were present in 70% at initial and 63% at monitoring visit. Initial severe LRS were associated with WTC dust cloud exposure and mental health symptoms. Spirometry measures were not associated with LRS severity or trajectory; improvement in LRS was associated with improved lung function measured with forced oscillometry techniques. CONCLUSION: Many community patients in a WTC treatment program had severe LRS associated with exposures and mental health symptoms. Improvement in LRS was associated with improvement in measures of small airway function. Am. J. Ind. Med. 59:777-787, 2016. (c) 2016 Wiley Periodicals, Inc.

The World Trade Center (WTC) destruction released dust and fumes into the environment. Although many community members developed respiratory symptoms, screening spirometry was usually normal. We hypothesised that forced oscillation testing would identify functional abnormalities undetected by spirometry and that symptom severity would relate to magnitude of abnormalities measured by oscillometry. A symptomatic cohort (n=848) from the Bellevue Hospital WTC Environmental Health Center was evaluated and compared to an asymptomatic cohort (n=475) from the New York City Department of Health WTC Health Registry. Spirometry and oscillometry were performed. Oscillometry measurements included resistance (R5) and frequency dependence of resistance (R5-20). Spirometry was normal for the majority of subjects (73.2% symptomatic versus 87.6% asymptomatic, p<0.0001). In subjects with normal spirometry, R5 and R5-20 were higher in symptomatic versus asymptomatic subjects (median (interquartile range) R5 0.436 (0.206) versus 0.314 (0.129) kPa.L-1.s-1, p<0.001; R5-20 0.075 (0.085) versus 0.004 (0.042) kPa.L-1.s-1, p<0.0001). In symptomatic subjects, R5 and R5-20 increased with increasing severity and frequency of wheeze (p<0.05). Measurement of R5-20 correlated with the presence and severity of symptoms even when spirometry was within normal limits. These findings are in accord with small airway abnormalities as a potential explanation of the respiratory symptoms.

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.

BACKGROUND: Destruction of the World Trade Center (WTC) towers on September 11, 2001, released massive dust, gas, and fumes with environmental exposures for community members. Many community members have lower respiratory symptoms (LRSs) that began after September 11, 2001, and remain persistent. We evaluated whether systemic inflammation measured by C-reactive protein was associated with WTC dust exposures, persistent LRS, and lung function. METHODS: Community members self-referred for the treatment of symptoms related to September 11, 2001. C-reactive protein and lung function measurements, including spirometry and forced oscillation tests (impulse oscillometry system), were included as routine analyses in patients (2007 to 2012). RESULTS: Increased C-reactive protein levels were associated with the type of WTC dust exposure, LRS, reduced spirometry, and increased forced oscillation measurements (n = 724). CONCLUSIONS: Ongoing systemic inflammation measured years after the event was associated with WTC dust exposures, persistent LRS, and abnormal lung function in a community cohort. These findings have implications for treatment and surveillance.