title: Increased frequency of Gm(1,2;21) phenotype in HLA-DR4 positive seropositive rheumatoid arthritis.
abstract: Ninety-four patients with seropositive rheumatoid arthritis (RA) were typed for HLA-A, B, C and DR antigens and for immunoglobulin G (Gm) allotypes. Isolated IgG from patient serum was used to avoid interference of IgM rheumatoid factor (RF) with Gm typing in sera with high IgM-RF titer. Besides the association of seropositive RA with the antigen DR4 and an earlier disease onset in DR3/DR4 heterozygotes, we found the uncommon Gm phenotype Gm(1,2;21) significantly more often in our patient group than in healthy controls. Combination of HLA-DR and Gm data shows that individuals with both DR4 and Gm(1,2;21) are at a particularly high disease risk.
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000276:immunology*; D005260:Female; D005787:Gene Frequency; D006681:HLA-D Antigens / Q000276:immunology*; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology*; D015804:HLA-DR4 Antigen; D006801:Humans; D007129:Immunoglobulin Gm Allotypes / Q000235:genetics / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012217:Rheumatoid Factor / Q000276:immunology
chemical_list: D006681:HLA-D Antigens; D006684:HLA-DR Antigens; D015804:HLA-DR4 Antigen; D007129:Immunoglobulin Gm Allotypes; D007075:Immunoglobulin M; D012217:Rheumatoid Factor