Free intraglomerular malarial antigens.

Infection with Plasmodium berghei leads to a rapidly lethal disease in different strains of mice. Nude athymic mice are not able to produce circulating antibodies (IgG or IgM) against plasmodial antigens. Nevertheless, plasmodium-related antigens can be detected in the glomeruli of nude mice, in relation to the rising parasitaemia. This deposition is unrelated to the deposition of other immunoreactants (IgG, IgM or C3). The presence of the latter as well as the circulating auto-antibodies did not correlate with the intercurrent infection and control and experimental animals behaved likewise. These results indicate an intraglomerular localization of free malarial antigens. It is suggested that this may represent a basic mechanism for in situ formation of immune complexes in immunocompetent mice.