Increased proto-oncogene expression in peripheral blood T lymphocytes from patients with systemic sclerosis.

The expression of c-myc, c-myb, and c-ras proto-oncogenes, determined using RNA hybridization techniques (slot-blot), was significantly increased in peripheral blood T lymphocytes, but not in B cells, from 17 patients with systemic sclerosis with diffuse scleroderma, compared with the expression in normal control subjects. The magnitude of expression of c-myc and c-myb tended to be higher in patients with early, active disease. These results demonstrate an in vivo activation of T cells from systemic sclerosis patients, which may play an important role in the pathogenesis of the disease.