HLA-DQ ASSOCIATIONS IN TYPE-1 AUTOIMMUNE HEPATITIS

Objective: To determine whether, in patients with type 1 autoimmune he patitis and human leukocyte antigen (HLA) DR3 and DR4 positivity, any DQ antigen is disease-specific. Material and Methods: HLA class II typ ing was performed by restriction fragment length polymorphism in 103 p atients with type 1 autoimmune hepatitis, 104 patients with chronic vi ral hepatitis, and 80 normal subjects, A shared association with a dis ease-specific DQ antigen was sought in patients with HLA-DR3, DR4, aci d DR3-DR4, Results: Patients with HLA-DR3 and DR4 shared positivity fo r DQ2, DQ4, DQ5, DQ6, and DQ7, but the associations reflected establis hed linkages or mere of low frequency, Patients heterozygous for DR3-D R4 or homozygous for either DR3 or DR4 did not have a shared DQ antige n, Only the DR3-DQ2 haplotype distinguished patients with autoimmune h epatitis from normal subjects or those with chronic viral hepatitis, C onclusion: The DR3 and DR4 antigens are not associated with a single d isease-specific DQ antigen in type 1 autoimmune hepatitis, The DR3-DQ2 haplotype is the principal risk factor for the disease at our referra l center, Analyses by restriction fragment length polymorphism do not implicate a single susceptibility gene at the DQ locus.