Cross sectional study on cytokine production (TNF-alpha, IL-8) in German coalminers with progressive massive fibrosis and in control miners using a rapid whole-blood assay

Whole-blood release of tumour necrosis factor (TNF-alpha) and interleukin 8 (IL-8) was studied in 26 German ex-coalminers with progressive massive fib rosis (greater than or equal to A, ILO 1980; cases) and 26 ex-miners free o f pneumoconiosis (less than or equal to 0/1; controls) using a simple whole -blood assay. Cases and controls were matched individually by age and durat ion of coalmine dust exposure (5-year window). Whole-blood cytokine release was determined (blinded to case control status) in incubations without add itions (spontaneous) and with endotoxin (LPS, 3 ng ml(1)) or with coalmine dust (CMD; 5 mg ml(1)). CMD-stimulated TNF-alpha release was significantly increased and LPS-induced IL-8 release was significantly decreased in cases (matched t-tests: p < 0.01). No effect of duration of exposure was detecta ble in an unmatched analysis. No clear relationship with lung function para meters independent from case/control-status was observed, although a possib le positive association with central airway resistance was indicated by mul tiple regression for both CMD stimulated TNF-<alpha> and LPS-stimulated IL- 8. This study on individually matched coalminers validates previous finding s on monocyte TNF release as a marker for pneumoconiosis using a method (wh ole-blood assay) that is more feasible for epidemiological studies. The dif ferent response of TNF-alpha and IL-8 may be useful in studying the occurre nce of different endpoints like pneumoconiosis and lung function decrease.