Immunospecific binding of aflatoxins to human immunoglobulins in vitro

The aflatoxins are a family of complex coumarins produced by species of Aspergillus that are toxic and carcinogenic in animals. Four of the naturally occurring aflatoxins (B1, B2, G and G2) were incubated in vitro with whole human serum and subsequently tested for effects on antigenicities and electrophoretic mobilities of the proteins. Immunoelectrophoresis showed deviations of some of the precipitin arcs from normal patterns. Double diffusion experiments with affinity-isolated antibodies that are specific for the heavy chains of immunoglobulins IgA, IgG and IgM showed that the antigen-antibody binding sites of the heavy chains of IgA and IgM were blocked after incubation, but not those of IgG. These results are of interest regarding the specificity of immunochemical reactions in vitro that might be linked to specific immunological responses in diseases mediated by these toxins.