Impact of Persistent Preformed and De Novo Donor-Specific Antibodies Detected at 1 Year after Kidney Transplantation on Long-Term Graft Survival in Japan: a Retrospective Study.

Background We evaluated the impact of persistent preformed donor-specific antibody (DSA) and de novo DSA (dnDSA) detected at 1 year posttransplantation on long-term death-censored graft survival. Methods One hundred and sixty adult patients who received living kidney allograft with pretransplant-negative T-cell complement-dependent cytotoxicity crossmatch (CDCXM), and without periodic screening for DSA, were eligible for this study. All enrolled patients were retrospectively tested for DSA using the Luminex assay. The presence of DSA was analyzed in stored serum samples collected at 1 year posttransplantation. If the recipients had DSA, it was analyzed in the pretransplant serum sample. The detection of DSA solely in the 1 year posttransplant sample was defined as dnDSA, and DSA detection in both pretransplant and 1 year posttransplant samples was defined as persistent preformed DSA. Results DSAs were identified in 14 (8.8%) of the 160 patients. Seven patients had persistent preformed DSA, 6 had dnDSA, and 1 had both persistent preformed and dnDSA at 1 year posttransplantation. Death-censored allograft survival rates of patients with DSA versus those without DSA at 7 and 11 years were 77.9 vs. 97.8% and 60.6 vs. 89.2%, respectively. The graft survival rate was lower in patients with persistent preformed DSA and/or dnDSA. Each case of preformed DSA and dnDSA was associated with long-term graft survival. Conclusion The presence of persistent preformed DSA or dnDSA at 1 year posttransplantation may be a predictor of long-term graft survival. Further study is needed to evaluate whether periodic screening for DSA improves long-term graft survival.