Schweitzer E J, Yoon S, Fink J, Wiland A, Anderson L, Kuo P C, Lim J W, Johnson L B, Farney A C, Weir M R, Bartlett S T
Department of Surgery, University of Maryland School of Medicine, Baltimore 21201, USA.
Transplantation. 1998 Jan 27;65(2):242-8. doi: 10.1097/00007890-199801270-00017.
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.
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.
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.
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.
