Reactivity of envelope, capsid, and soluble antigens of Herpesvirus hominis types 1 and 2 in the indirect hemagglutination test.

Envelope, capsid, and soluble antigens of Herpesvirus hominis (HVH) types 1 and 2 were compared to crude antigens (disrupted HVH-infected cells) for potency, type-specificity, and diagnostic value in the indirect hemagglutination (IHA) test. The envelope appeared to be the predominant component reacting in the IHA test, but recurrent HVH infections increased the reactivity of human sera with capsid antigens. The soluble antigens reacted in the IHA test with HVH immune animal sera, but very few convalescent-phase human sera showed reactivity with soluble antigens. Overall, none of the subunit antigens showed greater type-specificity than did crude antigens in IHA tests with immune animal or convalescent-phase human sera. Recurrent infections with type 1 or type 2 viruses tended to broaden heterotypic reactivity of the patients' sera with both crude and subunit antigens, even in patients showing only a single type of antibody by IHA inhibition. Subunit antigens were no more sensitive than crude antigens in demonstrating significant IHA antibody titer rises for serodiagnosis of herpesvirus infections, and they generally had to be used at lower working dilutions than crude antigens.