Posttransplant donor-specific antibody characterization and kidney graft survival

Abstract This study was designed to investigate the clinical relevance of donor-specific antibodies (DSAbs) and their influence on graft survival. Among 106 patients who underwent cadaveric kidney donor transplantation and were monitored by flow cytometry crossmatch (FCXM) during the 1st posttransplantation year, 25 (23.6%) resulted positive for DS-Ab production. During a 2-year follow up only 12 of the 81 FCXM-negative patients (14.8%) suffered rejection vs 17 of 25 FCXM-positive patients (68%; P = 0.00 001). Correlating graft loss to DS-Ab production, 9 FCXMpositive patients lost the graft vs only 1 among the FCXM-negative patients. Aworse graft function was evidenced in FCXM-positive subjects who had also suffered rejection episodes than in those which had acute rejection but did not produce DS-Abs. A high incidence of HLAAB mismatches was found in FCXM-positive subjects which produced anti-class I antibodies. FCXM appears useful in estimating posttransplant alloimmune response. Moreover our findings confirm the harmful effects of anti-class I DSAbs on long-term graft survival.