Viral infections in renal allograft recipients treated with long-term immunosuppression.

Thirty-nine renal allograft recipients who had received continuous immunosuppression for six to 13 years were examined clinically and virologically for evidence of past or present viral infection. Twenty-five had common warts, usually on the hands. In most the warts had appeared about one year after transplantation; once present, they never disappeared. Six patients had had a zoster rash from two months to four years after transplantation. None had had jaundice, and there was no change in the frequency of colds or non-specific fibrile illness. Four patients had no cytomegalovirus complement-fixing antibodies throughout the observation period; in the other 35 the antibody titre had risen appreciably during the first three to four months after transplantation. Antibody titres were high (mean 64) at follow-up, being only slightly lower than the highest titres achieved during the immediate postoperative period. None of the patients had had symptomatic cytomegalovirus infection, and in only two was the virus isolated from the urine at follow-up; the titres were extremely low. No changes occurred in the frequency of herpes simplex eruptions. Although all patients had herpes simplex humoral antibody, none excreted the virus. Although cytomegalovirus antibody titres were high, virus excretion was rare, indicating that chronic cytomegalovirus infection in these patients is immunologically well controlled.