Aims/hypothesis The aim of this study was to investigate

Human leukocyte antigen (HLA) distribution in 7096 Korean cord blood (CB) units preserved at the public CB bank was analyzed by using the polymerase chain reaction with sequence-specific oligonucleotide probe (PCR-SSOP) method. A total of 14 HLA-A, 33 HLA-B, 13 HLA-DRB1 alleles and 2470 three-locus haplotypes were identified. The results are generally similar to those from the previous Korean studies, but the frequencies of less frequent haplotypes < 0.1% are more relevant and infrequent haplotypes with strong linkage disequilibrium were newly found because of the large sample size. Our results showed some similarities to those of other Asians but also some differences, suggesting a rationale for an Asian network for a hematopoietic stem-cell donor registry. Results from this large-scale analysis will be useful in Korean and Asian registry planning.

The human leucocyte antigen (HLA) system is the most polymorphic genetic system in humans, and HLA matching is crucial in organ transplantation, especially in hematopoietic stem cell transplantation. We investigated HLA-A, HLA-B and HLA-DRB1 allele and haplotype frequencies at allelic level in 10 918 Koreans from bone marrow donor registry in Korea. Intermediate resolution HLA typing was performed using Luminex technology (Wakunaga, Japan), and additional allelic level typing was performed using PCR-single-strand conformation polymorphism method and/or sequence-based typing (Abbott Molecular, USA). Allele and haplotype frequencies were calculated by direct counting and maximum likelihood methods, respectively. A total of 39 HLA-A, 66 HLA-B and 47 HLA-DRB1 alleles were identified. High-frequency alleles found at a frequency of ≥5% were 6 HLA-A (A*02:01, *02:06, *11:01, *24:02, *31:01 and *33:03), 6 HLA-B (B*15:01, *35:01, *44:03, *51:01, 54:01 and *58:01) and 8 HLA-DRB1 (DRB1*01:01, *04:05, *04:06, *07:01, *08:03, *09:01, *13:02 and *15:01) alleles. At each locus, A*02, B*15 and DRB1*14 generic groups were most diverse at allelic level, consisting of 9, 12 and 11 different alleles, respectively. A total of 366, 197 and 21 different HLA-A-B-DRB1 haplotypes were estimated with frequencies of ≥0.05%, ≥0.1% and ≥0.5%, respectively. The five most common haplotypes with frequencies of ≥2.0% were A*33:03-B*44:03-DRB1*13:02 (4.97%), A*33:03-B*58:01-DRB1*13:02, A*33:03-B*44:03-DRB1*07:01, A*24:02-B*07:02-DRB1*01:01 and A*24:02-B*52:01-DRB1*15:02. Among 34 serologic HLA-A-B-DR haplotypes with frequencies of ≥0.5%, 17 haplotypes revealed allele-level diversity and majority of the allelic variation was arising from A2, A26, B61, B62, DR4 and DR14 specificities. Haplotype diversity obtained in this study is the most comprehensive data thus far reported in Koreans, and the information will be useful for unrelated stem cell transplantation as well as for disease association studies.

To investigate HLA-associated genetic susceptibility to Meniere's disease in relation to type II collagen (CII) autoimmunity status, HLA-DRB1 genotyping and ELISA measurement of anti-CII antibody were performed in 41 Korean patients with Meniere's disease. In the anti-CII positive subgroup (20%) of patients, the frequency of HLA-DRB1*0405 was significantly increased (uncorrected) compared with both controls (63% vs 16%) and anti-CII negative patients (63% vs 12%). In the anti-CII negative subgroup, HLA-DRB1*1201 was significantly increased (uncorrected) (27% vs 10%) and DRB1*13 was decreased (6% vs 24%) compared with controls; these alleles appeared to confer susceptibility and resistance to the development of the disease. Association of HLA-DRB1*0405 with anti-CII positive Meniere's disease in this study suggests that it shares a specific HLA-DR sequence, QRRAA, as a genetic susceptibility factor with the anti-CII positive rheumatoid arthritis. In conclusion, whilst type II collagen autoimmunity may have a partial role in Meniere's disease, different HLA-DR alleles may also be associated with either susceptibility or resistance to the development of the disease in relation to anti-CII antibody status.