Kidney transplant outcomes in HLA desensitized patients with pretransplant CDC and/or FCM positive crossmatches.

BACKGROUND

Kidney transplant (KT) candidates with very high calculated panel reactive alloantibody (cPRA >95%) have limited chances to receive an HLA-matched transplant unless they undergo pretransplant desensitization.

OBJECTIVE

To assess the efficacy of immunoadsorption (IA) in desensitizing pretransplant KT candidates with high cPRA and positive crossmatch.

MATERIALS AND METHODS

This was a single-center retrospective cohort study involving highly HLA-sensitized patients (cPRA >85%). Forty-nine patients underwent HLA-incompatible (HLAi) KT, of whom 25 (51%) received kidneys from deceased donors. Of these 49 patients, 23 had either a positive complement-dependent cytotoxic cross-match (CDC) and/or a positive flow cytometry cross-match (FCM). The remaining 26 patients had donor-specific anti-HLA (DSAs) detectable only by Luminex (CDC and FCM cross-matches were negative). Only CDC-positive and FCM-positive patients were desensitized. These 49 patients were compared with 160 patients who had cPRA >85% but underwent HLA-compatible (HLAc) KT, i.e., without pretransplant DSAs.Pretransplant desensitization included IA sessions, rituximab, tacrolimus, steroids, and mycophenolate mofetil. Induction therapy consisted of antithymocyte globulins.

RESULTS

The mean follow-up duration was 7.4 ± 4 years. At 1-year and at last follow-up, 43 patient and death-censored graft survival rates were similar between HLAc and HLAi patients. However, HLAi patients experienced significantly more biopsy-proven rejections compared to HLAc patients. These rejections were predominantly antibody-mediated. Finally, the rate of infectious complications was similar between HLAc and HLAi patients.

CONCLUSION

IA in addition to immunosuppression is an effective option for desensitizing HLAi patients, yielding favorable long-term outcomes.