Immune complexes in Hodgkin's disease: isolation, immunochemical and physico-chemical analysis.
Immune complexes (IC) present in sera from patients with Hodgkin's disease (HD) were isolated using three different affinity columns: C1q-degalan, anti-C1q sepharose and conglutinin (K)-degalan. The isolated IC were analysed by immunoprecipitation, SDS-PAGE and sucrose density gradients and compared with IC similarly isolated from patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and in vitro prepared BSA-anti-BSA complexes. Isolated material from each disease, and BSA-anti-BSA complexes contained proteins compatible with true immune complexes--IgM, IgG, C1q and C3 breakdown components. Albumin, fibronectin and CRP, whose affinity for IgM, C1q and C3 are known, were co-isolated along with IC material. The size of isolated IC in HD ranged from 8-40S on sucrose density gradients. Despite the operational difference in detecting and isolating HD complexes via the C1q ligand (C1q-degalan or anti-C1q column) and C3bi (K-degalan), material purified by both methods showed remarkable similarity on SDS-PAGE and immunoprecipitation analysis. Although IC isolated from different diseases showed disparate banding patterns on SDS-PAGE this was attributed to a variation in the relative concentrations of constituent proteins--IgM, IgG and C3 breakdown products. IgM, IgG and C3 bind loosely, and non-specifically, to macromolecular aggregates formed around immune complexes. Using the anti-C1q column, most of this material could be eluted using 0.02M EDTA. Least protein, yet the most specific for antigen and antibody was eluted at pH 3.0.
D000936:Antigen-Antibody Complex / Q000032:analysis* / Q000302:isolation & purification; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001798:Blood Proteins / Q000032:analysis; D002499:Centrifugation, Density Gradient; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D006689:Hodgkin Disease / Q000276:immunology*; D006801:Humans; D005779:Immunodiffusion; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008970:Molecular Weight
D000936:Antigen-Antibody Complex; D001798:Blood Proteins