Donor-specific antibodies after ceasing immunosuppressive therapy, with or without an allograft nephrectomy.
Within the last few years, anti-human leukocyte antigen detection assays have significantly improved. This study asked, using the Luminex single-antigen assay, whether an allograft nephrectomy allowed donor-specific alloantibodies to appear that were not previously detected in the serum when the failed kidney was still in place. After losing the kidney allograft and stopping immunosuppressive therapy, the proportions of donor-specific alloantibodies and nondonor-specific alloantibodies were compared in patients who had (n=48; group I) and had not (n=21; group II) undergone an allograft nephrectomy. Allograft nephrectomies were performed at 150 days after kidney allograft loss, and the time between allograft nephrectomy and last follow-up was 538 ± 347 days. At kidney allograft loss, donor-specific alloantibodies were detected in three group II patients (14.2%) and six group I patients (12.5%). At last follow-up, donor-specific alloantibodies were detected in 11 patients (52.4%) without and 39 patients (81%) with an allograft nephrectomy (P=0.02). Anti-human leukocyte antigen class I donor-specific alloantibodies were positive in 23.8% of group II and 77% of group I patients (P<0.001); anti-human leukocyte antigen class II donor-specific alloantibodies were positive in 42.8% of group II and 62.5% of group I patients. Independent predictive factors for developing donor-specific alloantibodies after losing kidney allograft and stopping immunosuppressants were number of anti-human leukocyte antigen A/B mismatches at transplantation (zero versus one or more) and allograft nephrectomy. The development of donor-specific alloantibodies was significantly greater in patients with a failed kidney who had undergone an allograft nephrectomy compared with those patients who had not undergone allograft nephrectomy.