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

The association of primary sclerosing cholangitis (PSC) to HLA class II gen es was studied by comparing patients from five different European populatio ns. Deduced HLA-DRB1, DQA1, DQB1 haplotypes of 256 PSC patients from Englan d, Italy, Norway, Spain and Sweden were compared to those observed in 764 e thnically-matched controls. Increased frequencies of the DRB1*03, DQA1"0501 , DQB1*02 (RR=3.0, P<0.00001) and the DRB1*13, DQA1*0103, DQB1*0603 haploty pes (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 DRB1*03, DQA1*0501, DQB1*0 2 haplotype compared to 1% of the controls (RR=20, P<0.0001). The DRB1*04, DQA1*03, DQB1*0302 haplotype was significantly reduced in frequency (RR=0.4 , P<0.00001). Among Nor wegian, Swedish and British patients that did not c arry neither the DRB1*03, DQA1"0501, DQB1*02 nor die DRB1*13 DQA1*0103, DQB 1*0603 haplotype, an increased frequency of the DRB1*15, DQA1*0102, DQB1*06 02 haplotype was observed (RR=2.0, P<0.0001). Thus, PSC was found to be pos itively associated to three different HLA class II haplotypes (i.e. the DRB 1*03, DQA1*0501, DQB1*02, the DRB1*15, DQA1*0102, DQB1*0602 and the DRB1*13 , DQA1*0103, DQB1*0603 haplotypes) and negatively associated to one HLA cla ss II haplotype (i.e. the DRB1*04, DQB1*0302 haplotype).