title: Binding of immune complexes to IgA-sepharose 4B.
abstract: A method for the determination and removal of circulating immune complexes in pathological sera was developed using human secretory or dimeric myeloma IgA covalently bound to Sepharose 4B. IgA-Sepharose 4B was able to selectively bind heat or antigen-aggregated human IgG (circulating immune complexes) but not monomeric IgG. The absorbent was also able to remove a very high proportion (95%) of circulating immune complexes from pathological sera as determined by a turbidimetric technique. An immunoradiometric assay for the direct measurement of circulating immune complexes is described. The assay uses IgA-Sepharose 4B as an absorbent (for the binding of IgG immune complexes from sera) and 125I-rabbit anti-IgG antibody (for the quantitation of IgG immune complexes bound to IgA-Sepharose 4B). The mean value obtained for pathological sera (27.1 +/- 0.9) was significantly higher than that of normal sera (4.8 +/- 0.5).
mesh_terms: D000936:Antigen-Antibody Complex / Q000302:isolation & purification*; D002846:Chromatography, Affinity / Q000379:methods; D003126:Colostrum / Q000276:immunology; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000302:isolation & purification; D007071:Immunoglobulin A, Secretory / Q000302:isolation & purification; D007074:Immunoglobulin G; D009101:Multiple Myeloma / Q000276:immunology; D009391:Nephelometry and Turbidimetry / Q000379:methods; D011247:Pregnancy; D011863:Radioimmunoassay; D012016:Reference Values; D012685:Sepharose / Q000031:analogs & derivatives
chemical_list: D000936:Antigen-Antibody Complex; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; C044217:immunoglobulin A-sepharose 4B; D012685:Sepharose