Mycophenolate mofetil reduces the risk of acute rejection less in African-American than in Caucasian kidney recipients

Transplantation. 1998 Jan 27;65(2):242-8. doi: 10.1097/00007890-199801270-00017.


Background: Multicenter clinical trials have shown that mycophenolate mofetil (MMF) reduces the risk of acute rejection, but it is unknown whether African-Americans constitute a subgroup of recipients less likely to benefit from MMF.

Methods: This study compared the acute rejection rates within 6 months of kidney transplantation in MMF-treated transplant patients with those on azathioprine (AZA) at a single center. The study population consisted of 353 consecutive recipients of cadaver or living donor kidney transplants. African-Americans constituted 43% of the patients on AZA and 49% of the patients on MMF. Variables used in a Cox regression analysis included MMF immunosuppression, recipient race, type of transplant, delayed graft function, postoperative immune induction, average cyclosporine trough level, and HLA mismatch.

Results: Significantly fewer patients on MMF experienced a biopsy-proven rejection episode than those treated with AZA (24% vs. 42%, respectively; relative risk [RR]=0.57, P=0.001). This decrease in risk was greater in Caucasian transplant recipients (MMF vs. AZA: 16% vs. 46%, RR=0.35, P < 0.001) than in African-American patients (32% vs. 36%, RR=0.88, P=0.6). Within each race stratum, the mean cyclosporine trough levels averaged over 2-week intervals were nearly identical for AZA- compared with MMF-treated patients. In the regression model, the effect of MMF on the incidence of rejection was again less in African-American than in Caucasian patients.

Conclusions: Kidney recipients treated with MMF have a significantly lower risk of acute rejection within 6 months of transplantation than those given AZA. This reduction in risk is significantly less in African-American recipients than Caucasians.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Azathioprine / therapeutic use*
  • Blacks*
  • Female
  • Graft Rejection / ethnology*
  • Graft Rejection / prevention & control*
  • Humans
  • Immunosuppression Therapy
  • Immunosuppressive Agents / therapeutic use*
  • Kidney Transplantation* / immunology
  • Likelihood Functions
  • Male
  • Middle Aged
  • Multivariate Analysis
  • Mycophenolic Acid / analogs & derivatives*
  • Mycophenolic Acid / therapeutic use
  • Proportional Hazards Models
  • Regression Analysis
  • Risk Factors
  • Transplantation Immunology
  • Whites*


  • Immunosuppressive Agents
  • Mycophenolic Acid
  • Azathioprine