Comparison of binding of IgE and IgG antibodies to honeybee venom phospholipase-A
Paull, B.R.; Jacob, G.L.; Yunginger, J.W.; Gleich, G.J.
Journal of Immunology 120(6): 1917-1923
1978
ISSN/ISBN: 0022-1767 PMID: 659884 Document Number: 138561
The quantities and avidities were compared of Ig = 27.0%) of the total IgE protein; IgG antibody accounted for 0.073-0.210% (.hivin.X = 0.130%) of the total IgG protein. The relative avidities of IgE and IgG antibodies were assessed by the ability of equimolar amounts to bind radioiodinated PLA. In 2 patients, avidities of IgE and IgG antibody for PLA were comparable; in the 3rd, IgG antibody bound PLA more avidly than IgE antibody. The valence of IgE antibody was greater than 1.9, assuming that PLA behaved as a uinvalent ligand in extreme antigen excess. IgG antibody was able to inhibit binding of IgE antibody in the PLA radioallergsorbent test (RAST) from 10-40% at a molar excess of 10- to 1000-fold. The results indicated the following: IgE antibody to PLA accounts for a high percentage of total IgE protein; the avidities of IgE and IgG antibodies are similar (2 of 3 patients); the valence of IgE antibody approaches 2; and IgG antibody can interfere with the measurement of IgE antibody in the PLA RAST.