DNA TYPING OF HLA-DQ ALLELES BY GENE AMPLIFICATION OF DQA AND DQB VARIABLE EXONS: ANALYSIS OF DQA/DQB HAPLOTYPES

In the present report, we describe a DNA typing method that allows detection of all the polymorphic variants of DQA1 and DQB1 second exons. By the oligotyping procedure provided in this paper, we are able to identify 8 DQA1 and 13 DQB1 alleles and to type random individuals in any heterozygous combination. We provide the hybridization and washing temperatures for using either 32P labelled or non-radioactive probes. The discrimination power of this procedure, compared to serological and cellular techniques, is remarkable. Therefore, this typing method finds perfect application in transplantation immunology and it will be very helpful to optimize the matching of unrelated donors before BMT. It is apparent from our results that despite the linkage disequilibrium present between DQ and DR loci, a DR specificity may frequently be associated to different DQ haplotypes. This is the case for DR4, DR7, DR8, DR9, and DR13 specificities.