BACKGROUND: Due to the complexity of the HLA typing system, ambiguous situations occur frequently during HLA typing of the donors.
OBJECTIVE: To statistically analyze the ambiguous ratio and combined allele groups of HLA-A*02 high-resolution genotyping by using PCR-SSO flow fluorescent bead method, and to investigate the method to resolve the ambiguous results of HLA-A*02 high-resolution genotyping and improve the ratio of high-resolution genotyping.
METHODS: 1100 pieces of HLA genotyping were collected for statistical analysis. We calculated the percentages of those combinations that contained HLA-A*02:01\02:09 ambiguity, given by the software HLA Fusion 2.0; in the other hand, we searched out those alleles which were highly correlated with A*02:09 by comparing these combination percentages with the A*02:09 genetic polymorphism distribution.
RESULTS AND CONCLUSION: 279 out of 1039 effective samples (279/1039, 26.853%) were found for the results of having A*02:01/02:09 ambiguities that could be categorized into 19 groups in NMDP code. The most frequently groups were DMDC, DYVK, GMDD, GMDE. In another cases, 34 identified as carrying A*02:09 were analyzed appearing that A*02:09 was highly correlated to B*07:02(0.2647), DRB1*01:01(0.2647), DRB1*03:01(0.1176). We selected 38 high risky samples and tested their 4-7 exons, and confirmed by SBT, only 1 sample could be identified as A*0209, while other 241 samples lacked of A*02:09. A reasonable judgment based on statistical analysis and necessary review can effectively simplify the experimental procedures, save time, reduce costs, and increase high-resolution ratio.