A Rare HLA-DRB1∗14:22-DQB1∗04:01 Haplotype in a Kidney Donor: Implication in the Interpretation of Donor-Specific Antibody in Kidney Transplantation - A Case Report

Background The presence of donor-specific human leukocyte antigen antibodies (HLA-DSA) can be determined by performing Luminex assay with single-antigen beads. The single-antigen beads' panels cover the most frequent HLA alleles of the HLA-A, B, C, DRB1, DRB3/4/5, DQB, and DP loci, although the HLA typing for deceased donors often includes only HLA-A, B, and DR. Therefore, the information of haplotypic association between DRB1 and DQB1 is essential for the analysis of HLA-DSA, especially when HLA-DQ antibodies are identified in the patient's serum. Case Report We report the finding of a rare HLA-DRB1∗14:22-DQB1∗04:01 haplotype in a Thai potential kidney donor. HLA class I and class II high-resolution typing were performed by a method of polymerase chain reaction with the use of sequence-specific primers. The HLA-A∗24:02-C∗04:06-B∗13:01-DRB3∗02:02-DRB1∗14:22-DQA1∗05:05-DQB1∗04:01 haplotype in the kidney donor was confirmed by segregation analysis in the kidney donor's family. This rare haplotype was also identified in her father and the 2 of her offspring. Conclusions To our knowledge, this is the 1st report of the rare HLA-DRB1∗14:22-DQB1∗04:01 haplotype in Thai individuals. The information of the rare HLA-DR-DQ haplotypic association provides a caution for HLA laboratory personnel when analyzing HLA-DSA in a patient with HLA-DQ antibodies and the HLA-DQ typing of a deceased donor is unavailable.