Mastering the risk of HLA antibodies in kidney transplantation: an algorithm based on pretransplant single-antigen flow bead techniques

Abstract

The utilization of sensitive techniques of detection of HLA antibodies to define and measure sensitization has greatly evolved in recent years. We present here an approach to minimize the risk of HLA antibodies in kidney transplantation based on the evaluation of graft accessibility of sensitized patients by calculated PRA (cPRA) and estimation of potential matched donors (PMD) using a national simulation software program. This study included all registered patients on our waiting list (WL) for deceased donor (DD) kidney transplants. All patients were screened by single-antigen flow bead (SAFB) techniques. Of the 502 registered patients, 174 (34.7%) were sensitized. Among these, 48.3% (84 pts) had a cPRA>85%. For 75.3% of sensitized patients (90 pts with cPRA≤85% and 41 pts with cPRA>85%), the flow of PMD was considered sufficient to allow a transplant avoiding all unacceptable antigens. The 41 patients with a cPRA>85% (48.8%) had a satisfactory donor flow in the framework of the national prioritization program for highly sensitized patients. Finally, 43 sensitized patients (24.7%) were deemed eligible for a strategy of higher immunological risk through desensitization protocols or transplantation against HLA-DSAs. This approach provides a logical and systematic strategy to rationalize the access of sensitized patients to kidney transplantation minimizing the risk of HLA antibodies.