HLA-A TYPING - COMPARISON BETWEEN SEROLOGY, THE AMPLIFICATION REFRACTORY MUTATION SYSTEM WITH POLYMERASE CHAIN-REACTION AND SEQUENCING

In this study we typed HLA-A polymorphisms by a new sequence-based typ ing (SBT) method, which involved one PCR reaction and four sequencing reactions covering exon 2 and exon 3, This method allowed complete ide ntification of all known HLA-A alleles and revealed the presence of a new allele, named HLA-A2608. We also introduced sequencing of exon 4 for some samples in order to discriminate the allelic pairs that are i dentical in exon 2 and 3, thus improving SBT resolution. Finally, we c ompared the results obtained by SBT with data obtained by serological typing and the amplification refractory mutation system (ARMS-PCR). To gether, our results suggest that the SBT here described provides an op timal HLA-A typing technique that may be useful in selecting donor-rec ipient pairs in bone marrow transplantation between unrelated individu als.