Tumor Necrosis Factor-Alpha Gene Promoter Polymorphism in Coal Workers' Pneumoconiosis.

Tumor necrosis factor-alpha (TNF-alpha) is believed to play a central role in the pathogenesis of pneumoconiosis. TNF2, a polymorphism in the TNF-a gene promoter, has been associated with an increase in TNF-alpha production and airway inflammation. To investigate the frequency of TNF2 in patients who have coal workers' pneumoconiosis (CWP) and to determine whether it is associated with development of a large opacity in CWP, we investigated the expression ofthe TNF2 allele in 80 patients who had CWP and in 54 healthy controls using restriction fragment length polymorphism (RFLP). Compared to controls (10.2%), the frequency of the TNF2 allele was greater in the CWP patients (20.6%). Furthermore, the TNF2 allele was very common in patients who had a large opacity (28.2%) in comparison with 13.4% in those with simpleCWP. From these data, we suggest that the TNF2 allele is associated with the development of a large opacity in CWP.