Abnormalities of immunoregulation in progressive systemic sclerosis. Evidence for excess helper-cell function and altered B-cell function.

We investigated immunoregulatory function in patients with progressive systemic sclerosis (PSS) in terms of in vitro IgM synthesis. Suppressor-cell function seems normal in regard to the ability of concanavalin A-treated cells to inhibit IgM synthesis by normal cells. At 4 x 10(5) T cells to 3 x 10(5) allogeneic normal B cells per milliliter, T cells from patients with PSS induce significantly more IgM synthesis by normal B cells than do normal T cells. This increased helper T-cell function might be involved in the pathogenesis of the disease.