HLA DPB1 alleles provide protection against Crohn's disease in Caucasians

Objective: The aim of this study was to identify immunogenetic markers of susceptibility or protection in Crohn's disease. Design: HLA class II antigen frequencies were analysed and compared in a group of 118 Swedish patients with Crohn's disease and 158 unrelated healthy controls. Methods: HLA class II loci DRB1, DQB1 and DPB1 were typed using sequence-specific oligonucleotide probes to analyse enzymatically amplified locus-specific DNA. Results: HLA DR specificities, DQB1 alleles and DR/DQ haplotypes were not significantly associated with Crohn's disease. In contrast, significant differences were detected for HLA DPB1*0401, which was reduced in patients with Crohn's disease (39.5%) compared with healthy controls (65.8%), giving rise to a relative risk of 0.3 (P < 0.001)