We sought to determine whether the mode of sensitization in highly sensitized patients contributed to kidney allograft survival.

An analysis of the United Network for Organ Sharing dataset involving all kidney transplants between 1997 and 2014 was undertaken. Highly sensitized adult kidney transplant recipients [panel reactive antibody (PRA) ≥98%] were compared with adult, primary non-sensitized and re-transplant recipients. Kaplan–Meier survival analyses were used to determine allograft survival rates. Cox proportional hazards regression analyses were conducted to determine the association of graft loss with key predictors.

Fifty-three percent of highly sensitized patients transplanted were re-transplants. Pregnancy and transfusion were the only sensitizing event in 20 and 5%, respectively. The 10-year actuarial graft survival for highly sensitized recipients was 43.9% compared with 52.4% for non-sensitized patients, P < 0.001. The combination of being highly sensitized by either pregnancy or blood transfusion increased the risk of graft loss by 23% [hazard ratio (HR) 1.230, confidence interval (CI) 1.150–1.315, P < 0.001], and the combination of being highly sensitized from a prior transplant increased the risk of graft loss by 58.1% (HR 1.581, CI 1.473–1.698, P < 0.001).

The mode of sensitization predicts graft survival in highly sensitized kidney transplant recipients (PRA ≥98%). Patients who are highly sensitized from re-transplants have inferior graft survival compared with patients who are highly sensitized from other modes of sensitization.