[Expression of TNF-alpha in alveolar macrophages after stimulation with quartz dust, welding fume dust and asbestos fibers].

Alveolar macrophages have a potential for expressing and excreting many factors that are immunologically active and active on cytokines (monokines and lymphokines) and are thus indirectly involved in the genesis of pulmonary fibroses. One of these factors is the tumour necrosis factor alpha (TNF alpha). In the study presented here, the expression of TNF alpha-mRNA was investigated in macrophages stimulated in vitro with quartz dust, dust from cinders of welding furnaces, and asbestos, using non-radioactive in situ hybridization. There was a marked dependence of the expression of this cytokine on both time and stimulation. Macrophages stimulated by quartz dust showed the highest rate of expression compared with controls and other related stimuli. In addition, all stimuli yielded an expression that was elevated for a short period only and reached its peak after four hours. The results permit the conclusion that various professionally inhaled dusts possess different risk potentials in respect of lung damage mediated by macrophages and do not behave uniformly.