Serological Studies on Infectious Mononucleosis and Viral Hepatitis with Human Erythrocytes Modified by Different Strains of Newcastle Disease Virus

Abstract

Hemagglutinating properties of sera from cases of infectious mononucleosis and viral hepatitis, and certain other diseases have been studied, employing human red blood cells modified by adsorption and elution of Newcastle disease virus (NDV). Serum from 17 per cent of 59 cases of infectious mononucleosis agglutinated red cells modified by the Connecticut strain of NDV in higher titer than found in serum of normal individuals, whereas serum from 74.5 per cent of the same cases agglutinated red cells similarly modified by an Australian strain. Individual titers were often in a much higher range with the latter strain. Absorption experiments indicate that red cells modified by either strain of NDV react with the same component of serum. Elevated titers were found in serums from 32 per cent of 40 cases of viral hepatitis studied with red cells modified by the Connecticut strain of NDV, and 26 per cent of 90 cases similarly studied using an Australian strain. Elevated titers were obtained in 13 per cent of patients with other infectious diseases whose serum was tested against red cells altered by the Connecticut strain, and in 10 per cent employing an Australian strain. The amount of residual virus present on the red cell after adsorption and elution, the hemagglutinin titer against chicken and human red cells, and the infectivity titer for eggs were all closely comparable for these virus strains as well as for 2 other strains of NDV. When subjected to elevated temperatures, differences in the stability of the chicken red cell hemagglutinin of 4 strains of NDV were demonstrable.