HLA-DPB1 TYPING BY PCR-SSO REVERSE DOT-BL OT HYBRIDIZATION AFTER GROUP-SPECIFIC AMPLIFICATION

Background: The allelic diversity of HLA-DPB1 antigens can be determin ed at the DNA level after PCR amplification;The pattern of polymorphis m at the DPB1 locus makes it difficult to unambiguously assign all gen otypes in a typing system using one single pair of generic primers. Ma terials and Methods: We apply here a simple technique based on the rev erse dot blot analysis to the typing of HLA-DPB1 alleles. In order to increase its resolution, a group-specific amplification based on seque nce variations of the polymorphic region F was used subdividing the HL A-DPB1 alleles in 2 nonoverlapping families. A separate analysis was t hen performed within each group of alleles. Results: Using these 2 pri mer pairs, 21 group 1 and 30 group 2 alleles were separately amplified . From 1,378 possible allele combinations for DPB10101-5301 only 33 g ave ambiguous typing results compared to 61 using a single pair of gen eric primers. Conclusions: This procedure provides a rapid and simple HLA-DPB1 genotyping. Especially in heterozygotes the hybridization pat terns were easier to interpret. The utilization of group-specific ampl ification substantially reduced ambiguous typing results.