Immunoglobulin M-Immunoglobulin G mixed cryoglobulinemia in Schistosoma japonicum-infected rabbits.

Cryoprecipitation was observed in defibrinated serum from Schistosoma japonicum-infected rabbits. Ouchterlony immunodiffusion, sodium dodecyl sulfate-polyacrylamide gels, and anti-cryoprecipitate antiserum demonstrated the presence of immunoglobulin G (IgG), IgM, C3, fibrinogen, and an alpha-macroglobulin. Parasite antigen was not detected. IgG and IgM from pooled cryoprecipitates failed to react with each other in Ouchterlony immunodiffusion gels after separation by column chromatography. The data suggest that the IgG and IgM are not specifically complexed with each other but may simply be aggregates of altered proteins.