Abstract: | The appearance of a new virus specific antigen was demonstrated by an indirect immunofluorescence technique on cell surfaces of CMV infected human fibroblasts, 48–72 hr after inoculation. The development of antibodies to these membrane antigens was followed in thirty-nine serial sera from twelve patients with a virologically and/or serologically confirmed CMV infection. In all patients except one, membrane antibodies could be detected. Sera from four patients collected before infection were negative, as were sera taken 1–13 days after onset of symptoms. From the end of the second week of illness CMV-membrane antibodies as well as CMV macroglobulin antibodies to intracellular antigens were detectable. The membrane antibodies persisted until 335 days after onset of illness. They were mainly of the IgM class. Most positive sera also reacted with non-infected fibroblasts but to a lesser degree. This reaction became negative after prior absorption of the sera with non-infected fibroblasts, whereas the reaction with CMV-infected cells remained positive.Controls consisted of forty-five sera from healthy persons and nine sera from patients suffering from other herpes virus infections with antibodies to herpes simplex, zoster/varicella and Epstein-Barr virus. All but two sera were negative in the membrane immunofluorescence test. |