Tumor necrosis factor alpha (TNF-alpha) phenotypes of two polymorphic
systems were determined in 50 patients with alopecia areata, a common
inflammatory disease of the skin. The distribution of TNF-alpha T1, T2
phenotypes differed between patients with the patchy form of disease
and patients with totalis/universalis disease. There was no significan
t difference in the distribution of TNF-alpha G,A phenotypes between p
atient groups. The results of this study provide evidence of genetic h
eterogeneity between the two forms of alopecia areata, and suggest tha
t the TNF-alpha gene or a closely linked locus within the major histoc
ompatibility complex may play a role in the pathogenesis of the patchy
form of disease.