Intermediate-term graft loss after renal transplantation is associated with both donor-specific antibody and acute rejection.

BACKGROUND: Renal transplant recipients with de novo DSA (dDSA) experience higher rates of rejection and worse graft survival than dDSA-free recipients. This study presents a single-center review of dDSA monitoring in a large, multi-ethnic cohort of renal transplant recipients.
METHODS: The authors performed a nested case-control study of adult kidney and kidney-pancreas recipients from July 2007 through July 2011. Cases were defined as dDSA-positive whereas controls were all DSA-negative transplant recipients. DSA were determined at 1, 3, 6, 9, and 12 months posttransplant, and every 6 months thereafter.
RESULTS: Of 503 recipients in the analysis, 24% developed a dDSA, of whom 73% had dDSA against DQ antigen. Median time to dDSA was 6.1 months (range 0.2-44.6 months). After multivariate analysis, African American race, kidney-pancreas recipient, and increasing numbers of human leukocyte antigen mismatches were independent risk factors for dDSA. Recipients with dDSA were more likely to suffer an acute rejection (AR) (35% vs. 10%, P<0.001), an antibody-mediated AR (16% vs. 0.3%, P<0.001), an AR ascribed to noncompliance (8% vs. 2%, P=0.001), and a recurrent AR (6% vs. 1%, P=0.002) than dDSA-negative recipients. At a median follow-up of 31 months, the death-censored actuarial graft survival of dDSA recipients was worse than the DSA-free cohort (P=0.002). Yet, for AR-free recipients, there was no difference in graft survival between cohorts (P=0.66).
CONCLUSIONS: Development of dDSA was associated with an increased incidence of graft loss, yet the detrimental effect of dDSA was limited in the intermediate term to recipients with AR.