Antirat erythrocyte agglutinins.

Antirat hemagglutinins may be found in the sera of both normal and sick persons. High titers of these antibodies are influenced by the major blood groups, the antigen B tending to suppress these antibodies, and by age where juveniles have higher titers than adults. Elevated titers may be stimulated by immunization, injection of pooled gamma-globulin, infection, and transplantation.