Corticosteroid-induced lymphocytopenia in man: absence of splenic influence and effect of recipient serum.

Pharmacologic doses of corticosteroids produce a profound, transient lymphocytopenia in man. We have studied the role of the spleen and possible induction of cytolytic factors in the generation of this effect. A 200 mg IV dose of hydrocortisone-21-hemisuccinate was administered to five normal subjects and five subjects whose spleens had been removed as a result of trauma. Sequential peripheral blood lymphocyte counts and subpopulations were then determined, and the effect of serum (obtained from the recipients at several time points after steroid administration) on autologous lymphocyte viability was assessed in vitro. The asplenic subjects experienced the same marked lymphocytopenia as normal individuals, and post-steroid serum was not cytotoxic to autologous lymphocytes. The in vitro results support the view that corticosteroid-induced lymphocytopenia is not the result of lymphocytolysis in man. If lymphocyte redistribution is the cause, as has been suggested, our in vivo results directly demonstrate that the spleen does not play a major role.