HLA-DRB1 and hepatitis A virus infection: To that end, 27 samples from cases of hepatitis and 64 platelet apheresis samples from local donors in Scotland (controls) were genotyped using high-resolution typing for all HLA loci (HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DRB3, HLA-DRB4, HLA-DRB5, HLA-DQA1, HLA-DQB1, HLA-DPA1 and HLA-DPB1).