HUMAN CYSTICERCOSIS - ANTIGENS, ANTIBODIES AND NON-RESPONDERS

Abstract

Immunoelectrophoresis of sera from patients with brain cysticercosis against a crude antigenic extract from Cysticercus cellulosae indicated that nearly 50% of the patients do not make sufficient antibodies [Ab] to ostensively precipitate. The other 50% of the patients who do make precipitating Ab show heterogeneous response in the number of antigens [Ag] they recognize and in the type of Ag as classified by their electrophoretic mobilities. The most favored, Ag B, is recognized by 84% of positive sera and corresponds to one or a limited number of antigens isoelectric at pH 8.6. Indirect immunofluorescence with monospecific anti-human immunoglobulins (Ig), performed upon the immunoelectrophoretic preparations, reveals that all cysticercus Ag induce the synthesis of Ab in the Ig classes in the order IgG > IgM > IgE > IgA > IgD. Ag H (an anodic component) seems to favor IgE relative to its ability to induce IgG. Although in natural infection a good proportion of cysticercotic patients do not seem to mount an energetic Ab response against the parasite, giving rise to some speculations about immunosuppression, 50% do synthesize Ab, allowing optimistic expectations for vaccination of humans. Good results of vaccination in experimental animals were mediated by IgG Ab. A likely prospect for a human vaccine is Ag B because it is the most frequently detected in humans, although its immunizing and toxic properties remain unknown.