Subclinical rejection in tacrolimus-treated renal transplant recipients

Background. Subclinical rejection, defined as histologic acute rejection in the absence of graft dysfunction, has been suggested as a cause of chronic allograft rejection. In cyclosporine-treated patients, the incidence of subclinical rejection 3 months after transplant is reported to be approximately 30%. The intent of our study was to determine the incidence of subclinical rejection in tacrolimus-treated renal allograft recipients. Methods. We prospectively studied the incidence of subclinical rejection on surveillance biopsies performed 3 months after transplantation in 114 patients transplanted between September 1, 1998 and November 30, 2000. All patients received tacrolimus, mycophenolate mofetil, and prednisone, and 56% received antibody induction. Results. Subclinical rejection was detected in 2.6% of patients (3/114, 95% confidence interval 0.5-7.5%). Borderline changes were detected in 11% (12/114). Subclinical rejections were treated with bolus methylprednisolone. Conclusions. The incidence of subclinical rejection early after kidney transplantation is extremely low in tacrolimus-treated patients in whom early rejections are aggressively treated, suggesting that surveillance biopsies may not be necessary with this regimen.