Thymosin-induced reduction of "null cells" in peripheral-blood lymphocytes of patients with systemic lupus erythematosus.

Although thymosin, a thymic hormone, has been shown to restore cellular immunity in NZB/NZW mice, its effect in human systemic lupus erythematosus (S.L.E.) and other auto-immune disorders has not been tested. The present study shows for the first time that the proportion of "null cells" in peripheral-blood lymphocytes of patients with active S.L.E. is significantly decreased after in-vitro thymosin treatment. Thymosin has no effect on the percentages of T cells, B cells, and "null" cells in peripheral-blood lymphocytes from normal controls and patients with inactive S.L.E. and active rheumatoid arthritis. These findings suggest that thymosin may play an important part in the pathogenesis and treatment of this condition.