title: Relationship of HLA phenotype to immunoglobulin class present in immune complexes from patients with Behçet's syndrome.
abstract: The immunoglobulin class of circulating immune complexes (IC) was examined in 35 patients with Behçet's syndrome (BS) according to the HLA phenotype of these patients. Cold precipitable complexes were separated and assayed by laser nephelometry and polyethylene glycol precipitable complexes were assayed by rocker immuno-electrophoresis for IgG, IgA and C3. The results suggest that in patients with BS, HLA-B12 is associated with an increased proportion of IgG and a decreased proportion of IgA and C3 in their immune complexes, whilst the converse was found with HLA-B5 or DRw2. The ratio of IgA:IgG in immune complexes was therefore low in patients with HLA-B12 but high in those with HLA-B5 or DRw2. We suggest that a linkage may exist between HLA and gene(s) determining the immunoglobulin class, in response to antigenic stimulation or the site of antigen localization.
mesh_terms: D000936:Antigen-Antibody Complex; D001528:Behcet Syndrome / Q000276:immunology*; D003176:Complement C3 / Q000032:analysis; D006680:HLA Antigens / Q000032:analysis*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D010641:Phenotype
chemical_list: D000936:Antigen-Antibody Complex; D003176:Complement C3; D006680:HLA Antigens; D007070:Immunoglobulin A; D007074:Immunoglobulin G