HLA CLASS-I TYPING BY ONE-DIMENSIONAL ISOELECTRIC-FOCUSING AND IDENTIFICATION OF THE NEW VARIANTS IN THAI POPULATION

One-dimensional isoelectric focusing (1D-IEF) is the technique to defi ne HLA class I antigens based on difference in isoelectric point of HL A molecules. Different IEF subtypes are shown in different populations . In this study, 1D-IEF was employed to study HLA-A and -B subtypes in Thai population. A panel of 117 samples including all serologically d efined HLA-A and -B antigens in Thai population were typed by 1D-IEF. Serological specificities and subtypes correlated well with IEF result s and some antigens with unclear serological specificities could be In addition, more subtypes could be obtained by IEF A total of 17 IEF su btypes from HLA-A and 31 IEF subtypes from HLA-B could be identified. The subtypes predominantly found in Thai population were A2.3, A24.2, A11.1, A33.2, B15.2, B7.1 and B13.1. In addition, new IEF variants wer e identified in HLA-B35, B5, B56 and B48. The band positions of these variants were different from those previously described. These IEF sub types are HLA gene products which may be important in transplantation. The combination of IEF and serology for HLA typing can provide a bett er definition of each allelic product of HLA-A and-B.