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 define HLA class I antigens based on difference in isoelectric point of HLA 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 defined HLA-A and -B antigens in Thai population were typed by 1D-IEF. Serological specificities and subtypes correlated well with IEF results and some antigens with unclear serological specificities could be confirmed by IEF. In addition, more subtypes could be obtained by IEF than by serology. A total of 17 IEF subtypes 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 were identified in HLA-B35, B5, B56 and B48. The band positions of these variants were different from those previously described. These IEF subtypes are HLA gene products which may be important in transplantation. The combination of IEF and serology for HLA typing can provide a better definition of each allelic product of HLA-A and -B.