AN HLA-DR TYPING PROTOCOL USING GROUP-SPECIFIC PCR-AMPLIFICATION FOLLOWED BY RESTRICTION ENZYME DIGESTS

A simple PCR-based protocol for HLA-DR typing suitable for a routine practice is described. The method involves, first, a PCR amplification with seven different, group-specific (DR1, DR2, DR4. DR7, DR9, DR10, and DR3+5+6+8) primer-pairs, and second, typing of HLA-DR allele more exactly in DR1, DR2, DR4, and DR3+5+6+8 groups by digestion of PCR products with restriction enzymes distinguishing different HLA-DR types within each of the groups. Altogether 24 HLA-DR alleles, or any combination of these, can be typed. The whole procedure, starting from a blood sample, can be carried out during a single working-day. The method was tested by typing a set of homozygous cell lines, as well as a local panel previously typed by PCR/oligotyping. Also, 227 patients waiting for transplantation were typed to test the method in a routine setting. The results suggest that this kind of approach gives reliable HLA-DR types and works well in the routine use.