Angeliki Kazeros

MicroRNA-375 Regulation of Thymic Stromal Lymphopoietin by Diesel Exhaust Particles and Ambient Particulate Matter in Human Bronchial Epithelial Cells

Air pollution contributes to acute exacerbations of asthma and the development of asthma in children and adults. Airway epithelial cells interface innate and adaptive immune responses, and have been proposed to regulate much of the response to pollutants. Thymic stromal lymphopoietin (TSLP) is a pivotal cytokine linking innate and Th2 adaptive immune disorders, and is upregulated by environmental pollutants, including ambient particulate matter (PM) and diesel exhaust particles (DEP). We show that DEP and ambient fine PM upregulate TSLP mRNA and human microRNA (hsa-miR)-375 in primary human bronchial epithelial cells (pHBEC). Moreover, transfection of pHBEC with anti–hsa-miR-375 reduced TSLP mRNA in DEP but not TNF-α–treated cells. In silico pathway evaluation suggested the aryl hydrocarbon receptor (AhR) as one possible target of miR-375. DEP and ambient fine PM (3 μg/cm2) downregulated AhR mRNA. Transfection of mimic-hsa-miR-375 resulted in a small downregulation of AhR mRNA compared with resting AhR mRNA. AhR mRNA was increased in pHBEC treated with DEP after transfection with anti–hsa-miR-375. Our data show that two pollutants, DEP and ambient PM, upregulate TSLP in human bronchial epithelial cells by a mechanism that includes hsa-miR-375 with complex regulatory effects on AhR mRNA. The absence of this pathway in TNF-α–treated cells suggests multiple regulatory pathways for TSLP expression in these cells.

Elevated Peripheral Eosinophils Are Associated with New-Onset and Persistent Wheeze and Airflow Obstruction in World Trade Center-Exposed Individuals

Background. Exposure to World Trade Center (WTC) dust and fumes is associated with the onset of asthma-like respiratory symptoms in rescue and recovery workers and exposed community members. Eosinophilic inflammation with increased lung and peripheral eosinophils has been described in subpopulations with asthma. We hypothesized that persistent asthma-like symptoms in WTC-exposed individuals would be associated with systemic inflammation characterized by peripheral eosinophils. Methods. The WTC Environmental Health Center (WTC EHC) is a treatment program for local residents, local workers, and cleanup workers with presumed WTC-related symptoms. Patients undergo a standardized evaluation including questionnaires and complete blood count. Between September 2005 and March 2009, 2462 individuals enrolled in the program and were available for analysis. Individuals with preexisting respiratory symptoms or lung disease diagnoses prior to September 2001 and current or significant tobacco use were excluded, Results. One thousand five hundred and seventeen individuals met the inclusion criteria. Patients had a mean age of 47 years, were mostly female (51%), and had a diverse race/ethnicity. Respiratory symptoms that developed after WTC dust/fume exposure and remained persistent included dyspnea on exertion (68%), cough (57%), chest tightness (47%), and wheeze (33%). A larger percentage of patients with wheeze had elevated peripheral eosinophils compared with those without wheeze (21% vs. 13%, p < .0001). Individuals with elevated peripheral eosinophils were more likely to have airflow obstruction on spirometry (16% vs. 7%, p = .0003). Conclusion. Peripheral eosinophils were associated with wheeze and airflow obstruction in a diverse WTC-exposed population. These data suggest that eosinophils may participate in lung inflammation in this population with symptoms consistent with WTC-related asthma.

Application of the Asthma Phenotype Algorithm from the Severe Asthma Research Program to an Urban Population

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

Systemic Inflammation Associated With World Trade Center Dust Exposures and Airway Abnormalities in the Local Community.

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.

Longitudinal Spirometry Among Patients in a Treatment Program for Community Members With World Trade Center-Related Illness

Objective: The course of lung function in community members exposed to World Trade Center (WTC) dust and fumes remains undefined. We studied longitudinal spirometry among patients in the WTC Environmental Health Center (WTCEHC) treatment program. Methods: Observational study of 946 WTCEHC patients with repeated spirometry measures analyzed on the population as a whole and stratified by smoking status, initial spirometry pattern, and WTC-related exposure category. Results: Improvement in forced vital capacity (54.4 mL/yr; 95% confidence interval, 45.0 to 63.8) and forced expiratory volume in 1 second (36.8 mL/yr; 95% confidence interval, 29.3 to 44.3) was noted for the population as a whole. Heavy smokers did not improve. Spirometry changes differed depending on initial spirometry pattern and exposure category. Conclusion: These data demonstrate spirometry improvement in select populations suggesting reversibility in airway injury and reinforcing the importance of continued treatment.

Oscillometry complements spirometry in evaluation of subjects following toxic inhalation

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. Small airway dysfunction in a symptomatic population with normal spirometry years after exposure to WTC dust http://ow.ly/TAxxf

Isolated small airway reactivity during bronchoprovocation as a mechanism for respiratory symptoms in WTC dust-exposed community members

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.

Improvement in severe lower respiratory symptoms and small airway function in World Trade Center dust exposed community members

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.