25-P

Abstract

Aim To assess the presence of sequential HLA-Class I and Class II Allelic Antibodies in Patients waiting on Renal Transplants. Methods A total of 400 Patients tested in 5 Consecutive Quarters for HLA-Specific antibodies using Luminex Single Antigen Bead (SAB) were analyzed. Results In all, 56 (14%) patients had allele specific HLA antibodies. Eight patients had only Class I, 28 had only Class II, and 20 had both Class I and Class II allele-specific antibodies. Of the 8 patients with Class I allele specific antibodies in sequential samples, one patient had 5 consecutive A∗33:01 and A∗33:03 antibodies, and had 3 consecutive A∗30:01 antibodies. Another patient had 4 consecutive C∗07:02, and one had 2 consecutive C∗02:02 antibody. One patient each had 3 consecutive A∗02:03, A∗24:03, B∗08:01, C∗05:01. Seventeen patients had DQA allele specific antibodies; 5 with DQA∗03; 3 with DQA∗01, 1 each with DQA∗02, DQA∗04, 4 had DQA∗05, and 2 had DQA∗06 allelic antibodies in consecutive samples. In all, 8 patients had DQB∗06 allelic antibodies in 3 consecutive samples. Thirty-two patients had consecutive DRB3 Allelic antibodies: 10 with DRB3∗01, 13 had DRB3∗03 allele specific antibodies, 9 had DRB3∗02. Seven patients showed DRB5∗01; 3 had Consecutive Allelic antibodies against DR4 and DR14 were seen in 3 and 5 patents respectively. Among the 56 patients, 20 had consecutive Class I and II antibodies, Class II being predominant. Conclusions While antibody reactivity towards a particular HLA antigen is expected to indicate reactivity to most of the alleles of that specific antigen, our analysis based on consecutive samples from 400 patients show that a considerable proportion had sequential allele specific antibodies and more often towards Class II alleles. Documentation of allele specific antibodies could be useful in accepting or rejecting an organ. This information also indicates the advantage of having allele level HLA typing of solid organ transplant patients and donors.