Cytokine genotype and phenotype effects on lung function decline in firefighters.

Abstract

We conducted this study to evaluate the association of cytokine genotypes and sputum concentrations on longitudinal decline in lung function in firefighters. In 67 firefighters with at least four pulmonary function tests, DNA was analyzed for functional polymorphisms of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1RA), IL-8, IL-10, tumor necrosis factor-alpha (TNF-alpha) genes, and sputum evaluated for cytokine concentration by ELISA. The annual rate of FEV1 decline was greater in firefighters with TT genotypes at IL-10 (-819) (P=0.009) and with CT or TT genotypes at IL-1RA (2018) (P=0.050). These genotypes were not associated with concentrations of sputum cytokine, but increased IL-1RA was associated with a slower rate of FEV1 decline (P=0.025), as was increased sputum macrophage count (P=0.002). Cytokine genotypes were associated with the rate of FEV1 decline but did not alter concentrations of sputum cytokine. Increased sputum IL-1RA may be protective.