Analysis of histologic changes during early rejection after renal transplantation by performing protocol biopsy at 1...

In this retrospective study, we analyzed histologic changes identified through protocol biopsy (PB) at 1 year after kidney transplantation (KT). We focused on the pathologic changes observed in patients with a history of treatment for graft rejection within 1 year of transplantation.

Between January 2008 and December 2011, 56 patients underwent KT at our center. We assessed the histologic findings observed at 1 year after renal transplantation using the Banff 2007 classification. At our center, PBs are performed immediately after or at 1 hour after transplantation, and at 1 year after KT. PBs were performed in 39 patients; PBs could not be performed in 17 patients because of various causes. Of the 39 patients, 29 stabilized without clinical rejection and without treatment (the NTx group); 10 patients showed pathologic changes or clinical rejection after steroid pulse therapy within 1 year (the Tx group). We compared these 2 groups with respect to baseline data, renal function, and pathologic scores.

The interstitial fibrosis ("ci") score, according to the Banff classification, was significantly greater in the NTx group (0.89) than in the Tx group (0.50) at 1 year after transplantation.

The currently applied early steroid withdrawal regimen may be not be ideal for preventing pathologic changes occurring after KT. In addition to the PB performed 1 year after KT, PB should be performed within 1 year of renal transplantation to identify early signs of rejection and to provide access to appropriate treatment regimes.