RESUMEN
Objectives:The purpose of this study is to provide a HLA B locus genotyping method which is expected to compensate the unsatisfactory serology B locus typing and to explore the distribution of B22 subtypes.Methods:Taking standard cell lines provided by the XIIth International HLA Workshop as reference,the authors established the PCR SSP method for HLA B genotyping.By this method,the HLA B alleles of leukemia patients were typed and 57 individuals previously identified as HLA B22 by serologic typing were genotyped.Results:The results of B locus genotyping of 104 cell lines by PCR SSP and that of reported were completely concordant .Unambiguous results of 17 leukemia patients and their relations were gotten except one discordant from serology which was thought as mistaken serotyping .Out of 57 samples ,55 were confirmed to bear B54 or B55 or B56 allele,respectively ,with B54 being the most common allelic form,and another showed a unique amplifying pattern which was different from any known HLA B22 alleles so far reported, suggesting a new allele or "mismatched ”DNA double strands which needed further study .Conclusions:PCR SSP was proven to be a practical genotyping method for B locus because of its simplicity, rapidity ,accuracy and unvariability with changes of health.