Heterophile antibodies, M-antiglobulins and immunoglobulins in experimental trypanosomiasis.

Monkeys () were infected with different strains of and . The titres of non-sensitized sheep cell agglutinins (NSCAT), M-antiglobulins (rheumatoid factor-like globulins) and the levels of immunoglobulins (IgG, IgA and IgM) were determined in sera before and during the course of infections controlled by treatment with Suramin. Persistently high titres of NSCAT-agglutinins developed in monkeys infected with all three organisms. IgM levels increased in all animals reaching levels more than ten times the original values. The levels of IgA remained unchanged and of IgG slightly increased in some animals. Slightly elevated M-antiglobulin titres were occasionally found without any relation to the progress of infection. NSCAT-agglutinins were found to be macroglobulins (Sephadex G-200 immunoelectrophoresis, = 18·5) sensitive to β-mercaptoethanol treatment. Their activity was absorbed by sheep red blood cells, guinea-pig kidney cells and antigen.