The influence of mycophenolate mofetil on the incidence and severity of primary cytomegalovirus infections and disease after renal transplantation

Background. Mycophenolate mofetil (MMF) is increasingly used for immunosuppression after renal transplantation (RTx). The aim of our study was to investigate if the use of MMF has resulted in an increase in the frequency and severity of primary cytomegalovirus (CMV) infections. Methods. Retrospective study of adult RTx patients who were CMV seronegative and who received a kidney of a CMV seropositive donor in the period 1992-1997 (n = 84). Twenty-four of these patients were treated with MMF (in combination with cyclosporin and prednisone; MMF+) and the other 60 were the control group (cyclosporin and prednisone; MMF-). No CMV prophylaxis was given. CMV infection was defined as CMV seroconversion of IgG antibodies. CMV disease was defined as CMV infection and fever in combination with one or more of the following: leukocytopenia, thrombocytopenia, elevated alanine aminotransferase, or histological evidence of tissue invasive disease. Results. The incidence of primary CMV infections was similar in both groups (MMF+, 75%; MMF-, 63%). CMV disease was more frequent in the MMF+ group than in the MMF- group (67 vs 30%, P<0.05). In the patients with CMV disease, the use of MMF did not affect severity of symptoms, frequency of tissue invasive disease, or frequency or duration of treatment with ganciclovir. Conclusions. Addition of MMF to the immunosuppressive therapy after RTx did not result in an increase of primary CMV infections. However, these CMV infections led more often to CMV disease in patients treated with MMF than in those without MMF.