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. 2018 Feb;15(2):173-183.
doi: 10.1513/AnnalsATS.201703-276OC.

Blood Leukocyte Concentrations, FEV1 Decline, and Airflow Limitation. A 15-Year Longitudinal Study of World Trade Center-exposed Firefighters

Rachel Zeig-Owens  1   2   3 , Ankura Singh  1   2 , Thomas K Aldrich  2 , Charles B Hall  4 , Theresa Schwartz  1   2 , Mayris P Webber  1   3 , Hillel W Cohen  3 , Kerry J Kelly  1 , Anna Nolan  1   5   6 , David J Prezant  1   2 , Michael D Weiden  1   5   6
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Blood Leukocyte Concentrations, FEV1 Decline, and Airflow Limitation. A 15-Year Longitudinal Study of World Trade Center-exposed Firefighters

Rachel Zeig-Owens et al. Ann Am Thorac Soc. 2018 Feb.

Abstract

Rationale: Rescue/recovery work at the World Trade Center disaster site (WTC) caused a proximate decline in lung function in Fire Department of the City of New York firefighters. A subset of this cohort experienced an accelerated rate of lung function decline over 15 years of post-September 11, 2001 (9/11) follow-up.

Objectives: To determine if early postexposure blood leukocyte concentrations are biomarkers for subsequent FEV1 decline and incident airflow limitation.

Methods: Individual rates of forced expiratory volume in 1 second (FEV1) change were calculated for 9,434 firefighters using 88,709 spirometric measurements taken between September 11, 2001, and September 10, 2016. We categorized FEV1 change rates into three trajectories: accelerated FEV1 decline (FEV1 loss >64 ml/yr), expected FEV1 decline (FEV1 loss between 0 and 64 ml/yr), and improved FEV1 (positive rate of change >0 ml/yr). Occurrence of FEV1/FVC less than 0.70 after 9/11 defined incident airflow limitation. Using regression models, we assessed associations of post-9/11 blood eosinophil and neutrophil concentrations with subsequent FEV1 decline and airflow limitation, adjusted for age, race, smoking, height, WTC exposure level, weight change, and baseline lung function.

Results: Accelerated FEV1 decline occurred in 12.7% of participants (1,199 of 9,434), whereas post-9/11 FEV1 improvement occurred in 8.3% (780 of 9,434). Higher blood eosinophil and neutrophil concentrations were each associated with accelerated FEV1 decline after adjustment for covariates (odds ratio [OR], 1.10 per 100 eosinophils/μl; 95% confidence interval [CI], 1.05-1.15; and OR, 1.10 per 1,000 neutrophils/μl; 95% CI, 1.05-1.15, respectively). Multivariable-adjusted linear regression models showed that a higher blood neutrophil concentration was associated with a faster rate of FEV1 decline (1.14 ml/yr decline per 1,000 neutrophils/μl; 95% CI, 0.69-1.60 ml/yr; P < 0.001). Higher blood eosinophil concentrations were associated with a faster rate of FEV1 decline in ever-smokers (1.46 ml/yr decline per 100 eosinophils/μl; 95% CI, 0.65-2.26 ml/yr; P < 0.001) but not in never-smokers (P for interaction = 0.004). Higher eosinophil concentrations were also associated with incident airflow limitation (adjusted hazard ratio, 1.10 per 100 eosinophils/μl; 95% CI, 1.04-1.15). Compared with the expected FEV1 decline group, individuals experiencing accelerated FEV1 decline were more likely to have incident airflow limitation (adjusted OR, 4.12; 95% CI, 3.30-5.14).

Conclusions: Higher post-9/11 blood neutrophil and eosinophil concentrations were associated with subsequent accelerated FEV1 decline in WTC-exposed firefighters. Both higher blood eosinophil concentrations and accelerated FEV1 decline were associated with incident airflow limitation in WTC-exposed firefighters.

Keywords: eosinophils; longitudinal studies; lung injury; neutrophils; spirometry.

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Figures

Figure 1.
Figure 1.
Firefighters who participated in the lung function trajectory study. Shown are the total number of male firefighters who were employed by the Fire Department of the City of New York (FDNY) on September 11, 2001, and present at the World Trade Center (WTC) disaster site between September 11 and September 24, 2001; the number included in the final study cohort; and the population for our secondary analysis using post-bronchodilator pulmonary function test (PFT) data. FEV1 = forced expiratory volume in 1 second; FVC = forced vital capacity.
Figure 2.
Figure 2.
Lung function over time according to post–September 11, 2001 (9/11), FEV1 trajectory. (A) Yearly mean FEV1 in liters of World Trade Center disaster site–exposed Fire Department of the City of New York firefighters from September 11, 2000, to September 10, 2016, adjusted for race, height, and age on 9/11, according to post-9/11 FEV1 trajectory: accelerated decline (red), expected decline (blue), and improved FEV1 (green). SEM is shown by error bars; it is not shown if it is less than the size of the symbol. Numbers below the x-axis represent the sample size at each time point. (B) Yearly mean FEV1 percent predicted values. The dotted vertical line in (A and B) represents 9/11. FEV1 = forced expiratory volume in 1 second.
Figure 3.
Figure 3.
Predicted post–September 11, 2001 (9/11), FEV1 decline rate according to blood leukocyte concentrations and smoking status. (A) The associations between eosinophil concentration at the first post-9/11 pulmonary function test and predicted FEV1 decline rate (FEV1 slope) in milliliters per year among never-smokers (green) and ever-smokers (black). FEV1 slope is adjusted for individual-level variables listed in the Table 3 footnotes. Dashed lines show 95% confidence intervals. P for interaction = 0.004. (B) The association between polymorphonuclear leukocyte (PMN) concentration at the first post-9/11 pulmonary function test and predicted FEV1 slope in milliliters per year among never-smokers and ever-smokers. P for interaction = 0.01. FEV1 = forced expiratory volume in 1 second.
Figure 4.
Figure 4.
Incident airflow limitation according to post–September 11, 2001 (9/11), FEV1 trajectory. (A) Adjusted cumulative incidence of airflow limitation, defined as having two consecutive FEV1/FVC measurements less than 0.70 between 9/11 and September 10, 2016, according to post-9/11 FEV1 trajectory: accelerated decline (red), expected decline (blue), and improved FEV1 (green). (B) Adjusted cumulative incidence of airflow limitation on post-bronchodilator pulmonary function tests, defined as at least one post-bronchodilator FEV1/FVC ratio less than 0.70 between 9/11 and September 10, 2016, according to post-9/11 FEV1 trajectory. BD = bronchodilator; FEV1 = forced expiratory volume in 1 second; FVC = forced vital capacity.
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References

    1. Aldrich TK, Gustave J, Hall CB, Cohen HW, Webber MP, Zeig-Owens R, et al. Lung function in rescue workers at the World Trade Center after 7 years. N Engl J Med. 2010;362:1263–1272. - PMC - PubMed
    1. Aldrich TK, Vossbrinck M, Zeig-Owens R, Hall CB, Schwartz TM, Moir W, et al. Lung function trajectories in World Trade Center-exposed New York City firefighters over 13 years: the roles of smoking and smoking cessation. Chest. 2016;149:1419–1427. - PMC - PubMed
    1. Cho SJ, Nolan A, Echevarria GC, Kwon S, Naveed B, Schenck E, et al. Chitotriosidase is a biomarker for the resistance to World Trade Center lung injury in New York City firefighters. J Clin Immunol. 2013;33:1134–1142. - PMC - PubMed
    1. Naveed B, Weiden MD, Kwon S, Gracely EJ, Comfort AL, Ferrier N, et al. Metabolic syndrome biomarkers predict lung function impairment: a nested case-control study. Am J Respir Crit Care Med. 2012;185:392–399. - PMC - PubMed
    1. Nolan A, Naveed B, Comfort AL, Ferrier N, Hall CB, Kwon S, et al. Inflammatory biomarkers predict airflow obstruction after exposure to World Trade Center dust. Chest. 2012;142:412–418. - PMC - PubMed

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