Abnormal lymphocyte function in scleroderma: a study on identical twins

This paper describes immunologic studies on a set of identical twins discordant for the presence of scleroderma. The affected twin had a low absolute T-cell count, low numbers of T4 helper/inducer cells, and an increase in the T8 suppressor/cytotoxic cell count. The T cells of the patient responded poorly to mitogens and to allogeneic and autologous stimuli. By contrast, T-cell-helper activity for pokeweed mitogen-induced IgM synthesis was markedly enhanced in the patient. Furthermore, activated mononuclear cell supernatants from the patient markedly enhanced the synthesis of collagen by normal cultured fibroblasts. The unaffected twin by contrast displayed normal responses in these assays. The results suggest that the immunologic defects in scleroderma are not entirely genetically determined.