Naturally occurring blocking antibodies modulate immediate hypersensitivity responses in human filariasis.

摘要: Although the basophils and mast cells of patients with chronic helminth infection are sensitized specific IgE antibody frequently exposed to parasite antigens in vivo , these rarely manifest allergic reactions their parasites. To investigate regulatory mechanisms limiting immediate hypersensitivity responsiveness such patients, we used vitro antigen-induced histamine- release (HR) reaction human as a correlate responses. For 13 bancroftian filariasis HR responses were elicited by graded doses microfilarial antigen absence serum or presence normal serum, autologous from other infected patients. In all instances, sera contained factor that specifically inhibited antigen. Normal had no inhibitory effect, but effectively serum. This blocking was heat stable (56°C x 2 hr) nondialyzable. Its specificity demonstrated its inability block patient triggered anti-IgE anti-body lack effect on Hr response ragweed-sensitized reacted ragweed E. Fractionation staphylococcus protein A-Sepharose chromatography showed an IgG whose activity could be removed immunoabsorption filarial The levels high, comparable those reported for atopic immunotherapy regimens. These findings demonstrate antibodies directed against allergens regular component immune suggest potential role modulating antigens.