Incidence of donor‐specific antibodies in kidney transplant patients following conversion to an everolimus‐based calcineurin inhibitor‐free regimen

Scarce data exist regarding the incidence of donor‐specific antibodies (DSAs) in kidney transplant patients receiving everolimus‐based immunosuppression without calcineurin inhibitors (CNIs). The aim of this retrospective case–control study was to compare the incidence of de novo DSAs in patients converted to an everolimus‐based regimen without CNIs with that seen in patients maintained on CNIs. Sixty‐one DSA‐free kidney transplant patients who had been converted to an everolimus‐based regimen (everolimus group) were compared to 61 other patients maintained on CNIs‐based regimen (control group). Patients were matched according to age, gender, induction therapy, date of transplantation, and being DSA‐free at baseline. At last follow‐up, the incidence of DSAs was 9.8% in the everolimus group and 5% in the control group (p = ns). In the everolimus group, the increased incidence of DSAs between baseline and last follow‐up was statistically significant. Antibody‐mediated rejection occurred in 6.5% in the everolimus group and 0% in the CNIs group. The incidence of DSAs is numerically increased in kidney transplant patients treated with an everolimus‐based without CNIs. A study including a larger number of patients is required to determine whether a CNI‐free everolimus‐based immunosuppression significantly increases DSAs formation.