Frequency of hla class i and class ii alleles in korean aplastic anemia patients identified by molecular typing

Genetic susceptibility to a variety of disease has been shown and recent studies have suggested that HLA-DR2 is more commonty found m aplastic anema (AA) patients than in the general population- In most of these studies, however, the HLA phenotypmg were analyzed serotogicaJly. As the incidence, age distributions, and etiology of AA in Korean people are somewhat different from those of Caucasian's, we hypothesize that the HLA associations in Korean AA patients may also differ from those of western country. To investigate whether certain HLA genes are associated with susceptibility to Korean AA patients, we examine genotypes of both HLA class I and K alteles in 45 AA patients. Molecular typing was done in class I antigen using PCR-amplification refractory mutation system (ARMS) and in dass H. PCR-itequence specific oligonucleotide probes (SSOP). 43 class I antigens of AA patients were compared to those of 114 normal individuals. The significant genotypes in AA patients were HLA-A2601 (211% vs 7.0%: RR=3.51. P=.OI7). HLA-A2603 (11.6% vs 0.9%: HR MB4. /0061). Class If antigens of 45 patients with AA were also compared to 209 normal individuals. The significant genotype was only HLA-DRBl'15 altele (42.2% vs 24.9%: RR=5.53.=.03). Interestingly. AA patients who have HU-DQB)03 genotype showed lower incidence than control group (5)% vs 70% RFN).4a. P=0.025). Among 45 AA patients. 36 patients had redeved immunosuppresive therapy with anti-lymphocyte globulin (ALG) and cydosporlne and were evaluated for the association between treatment response and HLA genotype. 25 patient had either complete (13 patients) or partial response (12 patients), for an overall response rate of 69.4%. However, there was no significant difference in frequency of HLA alleles between responders and non responders. Conclusively, the frequency of HLA-A260I, A2603, and DRBH5 is increased and that of HLA-OQBl'03 is significantly decreased in patients with AA. These data suggest that the stronger association with certain class l and dass II antigens characterize genetic susceptibilities of AA in Korea.