Complement-mediated hemolysis of horse erythrocytes treated with equine infectious anemia virus.

Horse erythrocytes treated with equine infectious anemia virus hemagglutinin were found to be lysed after incubation with fresh horse serum at 37 degrees C. Fresh guinea pig serum induced more efficient hemolysis than horse serum. Direct immunofluorescence test revealed the adsorption of complement factors on the surface of the erythrocytes. Calcium and magnesium ions were necessary for the hemolysis to take place. Antibody against equine infectious anemia virus enhanced the virus-induced complement-mediated hemolysis. These observations indicated that the classical pathway of complement activation was responsible for this virus-induced hemolysis and suggest the possibility that virus antigen, anti-viral antibody and complement may play an important role in the genesis of the anemia of horses infected with the equine infectious anemia virus.