Background: Acute rejection in HLA matched kidney transplant recipients is uncommon, and the mechanisms involved are not well understood.

Methods: Data from 6 antigen HLA matched patients transplanted between 1994 and 2013 were analyzed to identify the incidence, risk factors, and outcomes associated with biopsy-proven acute rejection.

Results: A total of 278 HLA-matched patients were identified. Ten patients experienced BPAR (0.41 cases per 100 person-years, 95% CI 0.22-0.76). Thirty percent of patients who rejected had graft loss and 10% died compared to 30.8% graft loss and 28.4% death in non-rejectors (p=0.57 and 0.2, respectively). Mean time to rejection was 48.9 months (SD±57.9). Acute cellular (ACR), antibody mediated (AMR), and mixed rejection occurred in 5, 4, and 3 patients, respectively (Table 1). The majority of ACR biopsies were classified as Banff IA (n=5). Nine patients did not have DP matching. Four out of 10 patients had documented non-adherence to maintenance immunosuppression. There was no difference between patients who experienced rejection compared to those who did not based on age, gender, ethnicity, induction agent, PRA, sensitizing events, or infection in the first year of transplant.

Conclusions: In patients with 6 HLA matched kidneys, ACR was more common than AMR. Non-adherence was apparent in 40% of patients. Acute rejection was not associated with higher graft loss or death. Lacking DP typing for all patients, the pathogenesis of acute rejection in HLA-matched patients remains to be determined.

CITATION INFORMATION: Condon A, Astor B, Holdener K, Ellis T, Djamali A. Acute Rejection in 6 Antigen HLA Matched Kidney Transplant Recipients: Risk Factors and Outcomes. Am J Transplant. 2017;17 (suppl 3).

« Back to 2017 American Transplant Congress