HLA-DR AND HLA-DQ ARE NOT MARKERS FOR RAPID DISEASE PROGRESSION IN PRIMARY SCLEROSING CHOLANGITIS

Background/Aims: The association between primary sclerosing cholangitis (PSC) and the HLA haplotype A1, B8, DR3, DQ2 is well established. During the last few years, several additional HLA associations have been suggested in PSC. Furthermore, two different HLA-DR specificities have been reported to be markers for rapid disease progression. Our aim was to critically evaluate all of the current and as yet mostly unconfirmed HLA class II issues in PSC. Methods: Seventy-five Swedish patients with PSC were HLA-DR and HLA-DQ genotyped. Results: Of the recently described HLA associations in PSC, the association with the DRB1*1301, DQA1*0103, DQB1*0603 haplotype was decisively confirmed, whereas the DRB1*04 specificity was only slightly underrepresented and the frequency of DR2 was neutral. The association with codon 38 of DRB genes was secondary to the DRB3*0101 association. HLA-DR and HLA-DQ alleles were not found to be markers for disease progression. Conclusions: The HLA-associated genetic susceptibility to PSC cannot be attributed to specific amino acid positions of the DR beta chains. The highly discrepant results obtained in two previously reported studies and the present investigation indicate that HLA class II alleles are not markers for a more aggressive clinical course in PSC.