Infections in renal transplant recipients receiving mycophenolate versus azathioprine-based immunosuppression

Differences in the incidence, etiology, type, and outcome of infections occurring during the first 6 months after transplantation were evaluated in two consecutive cohorts of kidney recipients who received immunosuppressive regimens based on either azathioprine (plus antilymphocyte globulin, cyclosporine A, and prednisone) (ATG-AZA cohort) or mycophenolate-mofetil (plus cyclosporine A and prednisone) (MMF cohort). The overall incidence of infections in the two cohorts was similar (0.99 +/- 1.06 infections/patient in the MMF cohort and 1.04 +/- 0.99 in the ATG-AZA cohort, P=0.3), as was the incidence of bacterial and fungal infections. In patients who received mycophenolate, cytomegalovirus disease occurred at a higher incidence (0.3 +/- 0.54 vs. 0.1 +/- 0.34 episodes/patient, P=0.005) and affected the upper gastrointestinal tract more frequently (0.21 +/- 0.48 vs. 0.025 +/- 0.16 episodes of cytomegalovirus ulcerative esophagitis, gastritis, or duodenitis per patient; P=0.001). A nonsignificant trend toward a higher recipient survival for patients receiving mycophenolate was noted (100% vs. 95%, P=0.07). In multivariate analysis, the following factors were independently associated with a higher risk of cytomegalovirus disease: the serostatus R-/D+ (seronegative recipients who received a kidney from a seropositive donor) (RR=35.7 [95%CI, 7.4-166.7]), treatment with mycophenolate (RR=10.4 [95%CI, 2.7-38.4]), and the development of any episodes of acute rejection (RR=10.1 [95%CI, 2.5-41.6]). These data show that kidney recipients receiving mycophenolate have a higher incidence of cytomegalovirus disease, mainly affecting the upper gastrointestinal tract, compared to those receiving azathioprine-based immunosuppression.