Factors contributing to acute rejection in renal transplantation: the role of noncompliance.

Early episodes of acute rejection after renal transplantation reflect inadequate immunosuppression at a time of heightened immune challenge. Late acute rejection episodes, however, are less likely related to inadequacy of immunosuppression and may be due to patient noncompliance or overzealous weaning of immunosuppression. We evaluated 443 consecutive renal transplant recipients to determine the incidence and etiology of acute rejection. All episodes were confirmed by ultrasound-guided biopsy. The cause of each acute rejection was determined by chart review. Medication compliance was determined by history at the time of admission for biopsy. Over a follow-up period of 42 +/- 22 months, 87 patients (20%) suffered acute rejection. There was a trend toward fewer episodes of acute rejection with thymoglobulin induction and tacrolimus-based immunosuppression. Younger recipients had an increased risk of acute rejection (odds ratio 0.47, range 0.24-0.91, P = .027). Patient noncompliance with immunosuppression was associated with late acute rejection (P = .0002). Acute rejection increased the risk of allograft failure (P < .0001). Modifiable factors, including the choice of immunosuppression, reduce the risk of acute rejection. More importantly, the transplant recipient plays a substantial role in the maintenance of their allograft health through compliance with immunosuppressive drug therapy. Future strategies to improve compliance, including increased vigilance in high-risk patient groups, frequent medication review, and laboratory testing, should be encouraged.