title: HLA-DQ associations in type 1 autoimmune hepatitis.
abstract: OBJECTIVE
  To determine whether, in patients with type 1 autoimmune hepatitis and human leukocyte antigen (HLA) DR3 and DR4 positivity, any DQ antigen is disease-specific.
  
  
  METHODS
  HLA class II typing was performed by restriction fragment length polymorphism in 103 patients with type 1 autoimmune hepatitis, 104 patients with chronic viral hepatitis, and 80 normal subjects. A shared association with a disease-specific DQ antigen was sought in patients with HLA-DR3, DR4, and DR3-DR4.
  
  
  RESULTS
  Patients with HLA-DR3 and DR4 shared positivity for DQ2, DQ4, DQ5, DQ6, and DQ7, but the associations reflected established linkages or were of low frequency. Patients heterozygous for DR3-DR4 or homozygous for either DR3 or DR4 did not have a shared DQ antigen. Only the DR3-DQ2 haplotype distinguished patients with autoimmune hepatitis from normal subjects or those with chronic viral hepatitis.
  
  
  CONCLUSIONS
  The DR3 and DR4 antigens are not associated with a single disease-specific DQ antigen in type 1 autoimmune hepatitis. The DR3-DQ2 haplotype is the principal risk factor for the disease at our referral center. Analyses by restriction fragment length polymorphism do not implicate a single susceptibility gene at the DQ locus.
mesh_terms: D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology*; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005787:Gene Frequency; D005802:Genes, MHC Class II; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics*; D015803:HLA-DR3 Antigen / Q000235:genetics*; D015804:HLA-DR4 Antigen / Q000235:genetics*; D006239:Haplotypes; D006505:Hepatitis / Q000235:genetics / Q000276:immunology*; D006525:Hepatitis, Viral, Human / Q000235:genetics / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D006683:HLA-DQ Antigens; D015803:HLA-DR3 Antigen; D015804:HLA-DR4 Antigen