title: Infectious risks and optimal strength of maintenance immunosuppressants in rituximab-treated kidney transplantation.
abstract: BACKGROUND
  Rituximab, an anti-CD20 antibody, 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.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Chung Hee
authors.initials: CH
authors.lastname: Baek
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Yang
authors.forename: Kyung Sun
authors.initials: KS
authors.lastname: Park
authors.forename: Duck Jong
authors.initials: DJ
authors.lastname: Han
authors.forename: Jae Berm
authors.initials: JB
authors.lastname: Park
authors.forename: Su-Kil
authors.initials: SK
authors.lastname: Park