Infection with the helminthic parasites Ascaris lumbricoides and/or Necator americanus (hookworm) induces the production in man of high levels of serum IgE. The specificity of this IgE antibody when measured by RAST to a wide range of allergens was restricted in general to the helminthic antigens. Absorption of the sera with immunosorbents produced by coupling extracts of A. lumbricoides to CNBr activated Sepharose 4B established that Ascaris antigen specific IgE antibodies contributed a minor fraction of the total serum IgE. These observations suggest that parasitic infections in man as in laboratory animals potentiate the production of high levels of IgE with specificity unrelated to that of the parasite antigens. While the specificity of this potentiated IgE was not established, it is not directed towards inhalant allergens.

No abstract