Prevalence and subclass distribution of IgG-anti-IgE autoantibodies in atopy and parasitosis.

Using immunoblotting, we investigated sera of 60 patients with atopic dermatitis, 12 patients with helminth infections and 36 nonallergic controls, for anti-IgE autoantibodies. We found IgG anti-IgE autoantibodies in 62% of the atopics, 42% of the patients with parasitosis and 11% of the controls. IgG anti-IgE occurred most often (94%) in patients with atopic dermatitis plus additional atopic disorder, such as allergic asthma and rhinoconjunctivitis. In parallel, we found a significantly higher occurrence of IgG anti-IgE in the patients with high IgE levels compared to patients with low IgE levels (p less than 0.0005). The predominant subclasses of anti-IgE autoantibodies were IgG1 and IgG3 in atopy and parasitosis. In the controls, we found IgG4 and IgG3 anti-IgE, but no IgG1 autoantibodies. The frequency of IgG2 anti-IgE was very low; it occurred in 2 patients only. Prevalence and IgG subclass distribution of anti-IgE autoantibodies was found to be different for patients with atopic dermatitis, parasitic infection and for controls.