TNF alpha mRNA expression in bronchoalveolar lavage cells from patients with lung fibrosis and TNF alpha activity in the lavage supernatants.

Tumor necrosis factor alpha (TNF alpha) mRNA expression in bronchoalveolar lavage (BAL) cells from patients with lung fibrosis was studied by a reverse transcription-DNA polymerase chain reaction (RT-PCR). The results indicated that two thirds of the tested samples were TNF alpha mRNA positive. On the other hand, TNF alpha activity was detected in a big part of the BAL supernatants from the patients. Furthermore, recombinant TNF alpha was found to be mitogenic to lung fibroblasts. These data suggest that TNF alpha expression in BAL cells may play a role in the development of lung fibrosis in human.