HLA class II haplotypes in primary sclerosing cholangitis patients from five European populations.

The association of primary sclerosing cholangitis (PSC) to HLA class II genes was studied by comparing patients from five different European populations. Deduced HLA-DRB1, DQA1, DQB1 haplotypes of 256 PSC patients from England, Italy, Norway, Spain and Sweden were compared to those observed in 764 ethnically-matched controls. Increased frequencies of the DRB103, DQA10501, DQB102 (RR=3.0, P<0.00001) and the DRB113, DQA10103, DQB10603 haplotypes (RR=2.4, P<0.0001) were observed in all five patient groups. A total of 16% of the PSC patients were homozygous for the DRB103, DQA10501, DQB102 haplotype compared to 1% of the controls (RR=20, P<0.0001). The DRB104, DQA103, DQB10302 haplotype was significantly reduced in frequency(RR=0.4, P<0.00001). Among Norwegian, Swedish and British patients that did not carry neither the DRB103, DQA10501, DQB102 nor the DRB113, DQA10103, DQB10603 haplotype, an increased frequency of the DRB115, DQA10102, DQB10602 haplotype was observed (RR=2.0, P<0.0001). Thus, PSC was found to be positively associated to three different HLA class II haplotypes (i.e. the DRB103, DQA10501, DQB102, the DRB115, DQA10102, DQB10602 and the DRB113, DQA10103, DQB10603 haplotypes) and negatively associated to one HLA class II haplotype (i.e. the DRB104, DQB10302 haplotype).