Naturally occurring human IgA autoantibodies against IgE-DES myeloma protein. Prevalence and specificity.
The prevalence and specificity of naturally occurring human IgA anti-IgE autoantibodies (a-E Ab) were studied by ELISA with anti-IgA monoclonal antibodies (mAb) and a purified myeloma IgE as solid-phase protein, i.e., IgE-DES(kappa). Such detected IgA a-E Ab were common among adults, and significantly increased geometric means (GM) were found in patients with atopy (P = 0.006; n = 41; GM = 79.3 arbitrary units (AU)/ml) and filariasis (P = 0.02; n = 41; GM = 75.9 AU/ml), as compared with nonatopic controls (n = 42; GM = 48.8 AU/ml). No such difference was observed between age-matched nonatopic (n = 22; GM = 36.7 AU/ml) and atopic (n = 22; GM = 38.6 AU/ml) children. Children had significantly (P < 0.001) lower IgA a-E Ab concentrations than adults, probably as a result of age, because IgA a-E Ab concentrations and age of children were significantly correlated (n = 44; P < 0.05; r = 0.30). IgA a-E Ab concentrations were very low in cord serum (n = 32; median < 0.1 AU/ml). Sex did not influence IgA a-E Ab concentrations in any study group. The specificity of IgA a-E Ab in nine sera was studied by ELISA inhibition assay using IgE-DES myeloma as solid-phase protein and inhibitory proteins of the IgG, IgM, IgD, and IgE classes, including five different IgE myeloma proteins, as well as three enzymatic fragments of IgE-DES. The inhibitions indicated that all IgA a-E Ab tested reacted in a low-affinity reaction with determinants restricted to IgE-DES, i.e., the solid-phase protein.(ABSTRACT TRUNCATED AT 250 WORDS)
Magnusson
C G
CG
Department of Clinical Immunology, Karolinska Institute, Stockholm, Sweden.
D000293:Adolescent; D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000032:analysis*; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001323:Autoantibodies / Q000032:analysis* / Q000145:classification; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007073:Immunoglobulin E / Q000276:immunology; D009363:Neoplasm Proteins / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D000939:Epitopes; D007070:Immunoglobulin A; D009363:Neoplasm Proteins; D007073:Immunoglobulin E