PLASMA-LEVELS OF SOLUBLE TUMOR-NECROSIS-FACTOR RECEPTORS ARE INCREASED IN COAL-MINERS WITH PNEUMOCONIOSIS

Among other cytokines, tumour necrosis factor (TNF)-alpha is considere d to play a key role in the development of mineral dust related fibros is. Previously, we showed that ex-vivo release of TNF by peripheral bl ood monocytes is a marker for progression of coal workers' pneumoconio sis (CWP), Since soluble TNF receptors (sTNF-Rs) are believed to play an important regulatory role in systemic effects of TNF, we measured p lasma levels of sTNF-R55 and sTNF-R75 in coal miners with (n=28) or wi thout (n=76) CWP and in nonexposed controls (n=29), sTNF-R75 levels we re significantly increased in miners with CWP (2.09+/-0.44 ng . mL(-1) ) versus the nonexposed controls (1.86+/-0.23 ng . mL(-1)). Neither sT NF-R55 nor sTNF-R75 were related to exposure, stage of pneumoconiosis, smoking, or (spontaneous or ex-vivo induced) monocyte TNF-release. sT NF-R55 was increased in subjects with meditation (especially those usi ng cardiovascular drugs); upon exclusion of these subjects, sTNF-R55 w as found also to be significantly increased in CWP, In conclusion, bea ring in mind a confounding effect of medication, soluble TNF receptors are elevated in plasma of retired miners with coal workers' pneumocon iosis, These observations further support the important role of TNF-me diated pathways in the pathogenesis of mineral dust related fibrosis.