RESUMO
BACKGROUND: Immunosuppressive agents with higher potencies, such as tacrolimus and mycophenolate mofetil (MMF), have been introduced and widely accepted in clinical practice. This study evaluated the impact of these newer immunosuppressive drugs on the pattern and timing of post-kidney transplantation infections. METHODS: Data of kidney transplant recipients at the Seoul National University Hospital between January 1990 and November 2005 were analyzed. Recipients were divided into double immunosuppression (double group, n=198), triple immunosuppression including MMF (MMF group, n=253), and azathioprine (AZA, n=184) groups. RESULTS: The MMF group demonstrated higher graft survival and reduced rates of acute rejection within the fifth post-transplant year than both the AZA (P<0.001) and the double (P<0.001) groups. The overall incidence of infection in the first month was significantly higher in the MMF group (2.17/1,000 transplant-days) than in the AZA (0.73/1,000 transplant-days) and double (0.84/1,000 transplant-days) groups (P=0.01, ANOVA), and this was caused by viral infections that were significantly higher in the MMF (1.57/1,000 transplant-days) group than in the AZA (0.54/1,000 transplant-days) and double (0.67/1,000 transplant-days) groups. MMF was identified as a significant risk factor for viral infection (P=0.013; OR, 2.04; 95% CI, 1.16-3.60) in a multivariate logistic regression analysis. CONCLUSIONS: The results suggest that viral infection rates were higher in the MMF group and should be considered the primary source of perioperative infectious complications in MMF-receiving recipients.