The role of methylprednisolone in the modulation of cellular cytotoxicity and its relation to renal transplantation.

Inhibition of killer cell generation or suppression of their cytolytic capacity once formed represent fundamental mechanisms by which methylprednisolone may modulate cellular cytotoxicity in the transplant recipient. In vitro studies in mixed lymphocyte culture demonstrated that the presence of therapeutic concentrations of this agent (0.001-1 microgram/ml) during the sensitisation phase resulted in suppression of lymphocyte activation without cytolysis and marked or total inhibition of killer cell generation. A considerable individual variation in sensitivity to methylprednisolone-induced suppression was observed and killer cells once generated were resistant to this agent.