Usefulness of 3-month protocol biopsy of kidney allograft to detect subclinical rejection under triple immunosuppression with basiliximab: A single center experience

Background: Theoretically, an early protocol biopsy (PB) serves to detect subclinical rejection (SCR), allowing early treatment and prevention of acute rejection (AR) and chronic graft injuries. In this retrospective study, we investigated the incidence of biopsy-proven AR (BPAR) and the usefulness of a 3-month PB in detecting SCR in kidney transplant (KT) and simultaneous pancreas-kidney transplant (SPKT) recipients who received triple immunosuppression and basiliximab. Methods: Between January 2007 and September 2009, 116 patients received transplantation (KT = 112, SPKT = 4). In August 2008, we changed our PB policy and started to collect PB after 3 months instead of a pre-discharge biopsy performed 1 month after transplantation. Here we compare the incidence of SCR (defined as Banff grade Ia or higher) between the pre-discharge PB group and the 3-month PB group. PB was obtained from 41 patients before discharge (pre-discharge PB group), and from 49 patients 3 months after transplantation (3-month PB group). Results: Among all recipients, 21 patients were diagnosed with BPAR (estimated incidence of BPAR 20.1%); including 13 (62.0%) diagnosed from 31 to 180 postoperative days (POD), and only 3 (14.3%) within 30 POD. The incidence of BPAR was not different between the two groups (19.5 and 20.8%, respectively); however, 4 of 8 recipients in the 3-month PB group were diagnosed with SCR, compared to none in the pre-discharge PB group (P<0.05). Conclusion: Since the use of triple immunosuppression and basiliximab delayed the onset of AR, we recommend that in order to detect SCR, PB should be obtained 3 months postoperatively.