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 typing (SBT) method, which involved one PCR reaction and four sequencing reactions covering exon 2 and exon 3. This method allowed complete identification of all known HLA-A alleles and revealed the presence of a new allele, named HLA-A*2608. We also introduced sequencing of exon 4 for some samples in order to discriminate the allelic pairs that are identical in exon 2 and 3, thus improving SBT resolution. Finally, we compared the results obtained by SBT with data obtained by serological typing and the amplification refractory mutation system (ARMS-PCR). Together, our results suggest that the SBT here described provides an optimal HLA-A typing technique that may be useful in selecting donor-recipient pairs in bone marrow transplantation between unrelated individuals.