Drug-induced granulocytopenia with natural killer lymphocytosis after renal transplantation.

Following renal transplantation, a patient developed life-threatening granulocytopenia secondary to a specific combination of drugs which are commonly utilized in this setting. Coincident with the depression of granulocytes, an expansion of natural killer cells was seen, which may have been a consequence of immunosuppressive therapy required for allograft retention. Infection with cytomegalovirus may have contributed to both phenomena.