Autoimmune hepatitis in the Alaska Native population: autoantibody profile and HLA associations.

BACKGROUND & AIMS: The Alaska Native population is one of few populations in the world with a high prevalence of autoimmune hepatitis. The objective of this study was to determine the frequency and HLA and clinical associations of autoantibodies in Alaska Native people with autoimmune hepatitis.

METHODS

Alaska Native individuals with autoimmune hepatitis were recruited in clinics conducted statewide. Sera were tested for the presence of autoantibodies described in either autoimmune hepatitis or rheumatic disease. Associations between autoantibodies and HLA alleles and clinical features were assessed.

RESULTS

Seventy-one patients were included. At the study visit, 34 patients (47.9%) had antibodies to double-stranded DNA by immunofluorescence; 27 (38.0%) had anti-neutrophil cytoplasmic antibodies; and 11 (15.5%) had anti-Ro antibodies. Only one person had antibodies against soluble liver antigen, and in that person, anti-Ro was absent. Associations were found between autoantibodies and HLA alleles, including positive associations between HLA DR3 and anti-double-stranded DNA antibodies and between HLA DR14 and antineutrophil cytoplasmic antibodies. There was no association between autoantibodies and clinical outcomes.

CONCLUSIONS

As in other populations, the prevalence of anti-double-stranded DNA antibodies and antineutrophil cytoplasmic antibodies is high in Alaska Native people with autoimmune hepatitis. In contrast to data from other populations, there is a lower prevalence of anti-soluble liver antigen and a lack of association between anti-Ro and anti-soluble liver antigen. In addition, the HLA profile and associations with autoantibodies are unique. No clear prognostic implications of autoantibodies have emerged in this population.