OR30 HLA-DPB1* antigen frequencies in deceased donors: Mining the data

Abstract

Aim The OPTN recently implemented a new process wherein renal transplant candidates with cPRA values of 99% and 100% are given regional and national priority, respectively, for deceased donor (DD) kidneys. While the majority of these highly sensitized patients have HLA-DP antibodies, allocation offers frequently occur without donor HLA-DP typing. Furthermore, information regarding the frequency and distribution of HLA-DP antigens is not readily available. Herein we report the frequency and distribution of HLA-DP antigens in 1168 DDs typed over the past three years. Methods HLA-DPB1* typing was performed by SSO, SSP (One Lambda, Thermal-Fisher) or RT-PCR (Linkage Biosciences). Results Donors were 58.9% white, 32.4% black, 7.3% Hispanic and 1.4% API. As shown below, the frequency and distribution of HLA-DPB1 antigens varied significantly by race. For example, HLA-DPB1*04:01 is seen in 64.6% of whites and 16.2% of blacks while HLA-DPB1*01:01 is in 53.4% of black donors and only 9.1% of whites. Some HLA-DPB1* alleles appear racially restricted; e.g., HLA-DPB1*10:01 was observed in white and Hispanic but not black donors, while HLA-DPB1*85:01 was seen only in black donors. Multiple HLA-DPB1* alleles with a frequency of ⩾1% are not represented on any single antigen bead (SAB) products used to detect HLA antibodies. In contrast, SAB manufacturers allotted up to three beads for HLA-DPB1* 28:01, an allele not observed in any of the 1168 donors in this study. Conclusions OPO laboratories do not yet uniformly perform HLA-DP typing of deceased donors. In the absence of HLA-DP typing information, frequency tables as presented here can aid in the decision process of whether to accept/reject offers for patients with HLA-DPB1* antibodies. Hopefully, these data will stimulate bead manufacturers to provide SAB targets that more accurately reflect donor antigen distribution. Download full-size image