Infectious Risks and Optimal Strength of Maintenance Immunosuppressants in Rituximab-Treated Kidney Transplantation

Background: Rituximab, an anti-CD20antibody, effectively depletes B lymphocytes. It is not clear whether the use of conventional doses of mycophenolate mofetil (MMF), methylprednisolone and tacrolimus as maintenance immunosuppression in rituximab-treated kidney transplantation is associated with increased risk. Methods: We retrospectively evaluated 67 patients who underwent HLA-sensitized or ABO-incompatible living donor kidney transplantation after one dose of rituximab (200 or 500 mg) (group 1). Eighty-seven kidney transplant recipients who did not require rituximab served as a control (group 2). Results: Cytomegalovirus infection (16.4 vs. 5.7%, p = 0.031) and pneumonia (9.0 vs. 1.1%, p = 0.043) occurred more often in group 1, and 2 patients of group 1 died of infection. The doses of methylprednisolone and tacrolimus levels of the two groups were not different. MMF dose was reduced when serious infection occurred. The doses of MMF ( in grams/day) at the following times postoperatively were lower in group 1 than in group 2: 1 month: 1.26 +/- 0.42 vs. 1.40 +/- 0.39, p = 0.033; 3 months: 1.14 +/- 0.51 vs. 1.36 +/- 0.39, p = 0.011; 6 months: 1.07 +/- 0.50 vs. 1.30 +/- 0.42, p = 0.012; 1 year: 0.88 +/- 0.52 vs. 1.19 +/- 0.44, p = 0.009; 2 years: 0.69 +/- 0.55 vs. 1.25 +/- 0.49, p = 0.059, but the reduction of MMF doses did not increase the incidence of acute rejection in group 1 (4.5% in group 1 vs. 9.2% in group 2, p = 0.351). If patients who died with functioning graft were excluded, graft survival was 98.5% in group 1 and 100% in group 2. Conclusions: Serious infectious complications were increased in rituximab-treated kidney transplant recipients and it might be adequate to reduce the MMF dose from the early postoperative period. Copyright (C) 2012 S. Karger AG, Basel