Antibodies reactivity in human Schistosoma mansoni disease: detection and functional activity.

The detection and description of the functional activity of anti S. mansoni antibodies, and the relationship between five different antigen preparations, each corresponding to one immunological test for schistosomiasis, are described. This study, using functional assay, suggests that human antibodies detected by skin tests, direct lysis of sheep erythrocytes, complement fixation reaction, indirect immunofluorescent staining and complement-mediated death of schistosomules, show important dissimilarities in reactivities, and it is impossible to ascribe these reactivities to the same class of antibodies.

The separation of complement inhibitors from patients with schistosomiasis or Chagas' disease by gel filtration on Sephadex G-200: a preliminary study.

Gel filtration through Sephadex G-200 was used to detect anticomplement activity of sera from patients with Schistosoma mansoni infections or Chagas' disease. Protein content, immunoglobulins and hemolysis-inhibiting activity were assessed in the chromatographic effluent. The proteins were distributed as usual among three regular peaks. The presence of IgM (first peak) and IgG (second peak) in the fractions was demonstrated by the Ouchterlony method. No immunoglobulins were detectable in the third peak. A heat-labile activity which abolished the lysis of sensitized sheep red blood cells in the presence of guinea pig serum was eluted from the column in the ascending and top region of the first protein peak and in the top region of the second protein peak (fractions from schistosomiasis or chagasic patients). Furthermore, a potent anti-complement activity was eluted from sera of chagasic patients far from the first and second protein peaks, just before the third peak.