Safety and Health at Work 2010;1:69-79 Original Article

Objectives: Various cytokines induced by inhalation of coal dust may mediate infl ammation and lead to tissue damage or fi brosis, such as coal workers ’ pneumoconiosis (CWP). Methods: To investigate the relevance of serum cytokines in CWP, the levels of serum interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) as CWP biomarkers in 110 retired coal miners (22 controls and 88 CWP subjects) were related to cross sectional fi ndings and 1-year progressive changes of the pneumoconiosis. Progressive changes of CWP were evaluated by paired comparison of chest radiographs. Analysis by a receiver operating characteristic (ROC) curve assessed the biomarker potential of each cytokine. Results: The mean serum IL-8 level was signifi cantly higher in CWP compared to controls and IL-8 levels correlated with the degree of CWP. The median serum TNF-α level was signifi cantly higher in subjects with progressive CWP compared to subjects without CWP progression. The area under the ROC curve for IL-8 (0.70) and TNF-α (0.72) for CWP identifi cation and progression, respectively, indicated the biomarker potential of the two cytokines. Serum cutoff values of IL-8 and TNF-α were 11.63 pg/ml (sensitivity 69%; specifi city 64%) and 4.52 pg/ml (sensitivity 67%; specifi city 79%), respectively. Conclusion: The results suggest that high levels of serum IL-8 are associated with the presence of CWP and those of serum TNF-α are associated with the progression of CWP