Airflow Obstruction and Monocyte TNF Release in Coal Workers

Abstract

Respiratory health of 102 retired coal miners was assessed by chest radiographs, lung function measurements, and questionnaires, and related to tumor necrosis factor-alpha (TNF-α) production by blood monocytes upon priming with different stimuli. The objective was to assess a possible relationship between airflow obstruction and TNF-α production in retired coal workers. No significant differences in lung function were observed between cases of coal workers' pneumoconiosis (CWP) (n = 27; >%) and references (n = 75; = >%), nor was the effect of cumulative exposure on flow volume or impedance parameters significant. TNF-α release upon stimulation of blood monocytes with coal mine dust was significantly increased in cases with International Labour Organisation (ILO) score Oil (doubtful cases) compared to references and cases with a higher ILO score. Airflow limitation defined either as a FEV₁ < 80% (N = 10; 5 cases of CWP) or as a resonance frequency >15 Hz accompanied by a negative frequency dependence of resistance (N = 9; 4 cases of CWP) was significantly related to high levels of TNF-α release upon stimulation with endotoxin and silica, with silica showing the strongest relation. These data suggest that in this group airflow limitation is associated with an increased expression of inflammatory mediators indifferent of the presence of pneumoconiosis.