The Use of an Immunofluorescence Technique for the Determination of Antibodies to Cytomegalovirus Strains in Human Sera

Abstract

Abstract An immunofluorescence technique was used to investigate antigenic heterogeneity among cytomegalovirus (CMV) strains. Twelve strains of human CMV were examined by titration with their homologous human sera. The strains were selected to reflect a range of geographic origin, site and year of recovery, age and clinical disease of the host. Antigens from CMV strains AD 169 and Davis, a simian CMV strain, herpes simplex and varicella-zoster (VZ) viruses were included. On the basis of this initial study, the human CMV strains studied appeared to fall into three groups. Two strains recovered in Taiwan formed one distinct group. Other strains from Taiwan, however, were not found to give the same reaction pattern, so the difference did not appear to be due strictly to geographic origin. UW-1 and UW-2 strains from neonatal infections and another Seattle strain from a case of recurrent parotitis constituted a second group. The remaining strains fell into an intermediate group, distinct from the Taiwan strains. No similar differentiation was found in complement-fixation (CF) tests with the same sera and antigens. Human CMV strains did not appear to cross-react in the immunofluorescence test with other members of the herpesvirus group, including the CMV strain of simian origin. The specificity of this technique warrants its use as a diagnostic tool for virus identification, since most of the human CMV strains employed as antigens detected antibody in any of the sera tested. Although the CF test appeared to be species-specific for cytomegaloviruses, and hence may have the most general utility for antibody detection, the greater sensitivity of the fluorescent antibody (FA) technique warrants its use for detecting small amounts of antibody when the correct antigen can be ascertained.