Do IgE-IgG complexes occur in the circulation?
IgG anti-IgE autoantibodies in human allergic sera have been investigated using an enzyme immunoassay on microplates coated with anti-human IgE MoAb. After incubation with serum, the plates were developed with peroxidase-labelled anti-human IgE MoAb for the determination of total IgE levels, or with anti-IgG MoAb for evaluating IgG anti-IgE autoantibodies. Using this methodology, no correlation was found between total IgE and IgG anti-IgE levels in groups of sera of allergic individuals. Although the results obtained with enzyme-labelled anti-IgG are often interpreted as indicative of IgE-IgG complexes captured from the serum, molecular sieving on gel columns as well as direct ultrafiltration experiments through 300-kD membranes demonstrate that such complexes do not occur preformed in the circulation, but arise de novo on the anti-IgE-coated solid phase during in vitro incubation with human serum. It is suggested that IgG anti-IgE autoantibodies react with IgE only after the latter has undergone a conformational change, either by colloidal manipulation or after reaction with allergen.
Boluda
L
L
Research Group C.B.F. LETI, Tres Cantos, Madrid, Spain.
Berrens
L
L
D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D000936:Antigen-Antibody Complex / Q000097:blood*; D001249:Asthma / Q000097:blood / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood; D003876:Dermatitis, Atopic / Q000097:blood / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D046911:Macromolecular Substances
D000888:Antibodies, Anti-Idiotypic; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D007074:Immunoglobulin G; D046911:Macromolecular Substances; D007073:Immunoglobulin E