Cytomegalovirus isolations from cell cultures derived from Epstein-Barr virus-associated nasopharyngeal carcinoma.

Cytomegalovirus (CMV) was isolated in cell cultures derived from 2 of 11 nasopharyngeal carcinoma (NPC) biopsy specimens from North African patients. All these cases were Epstein-Barr virus (EBV)-associated NPC. Morphologic cytopathic changes and viral replication not associated with EBV were observed after 2 months in culture. Virus identification was achieved by immunofluorescence studies, and cell culture antigens were tested by the use of complement fixation and indirect hemagglutination. All these NPC patients had been infected by herpes simplex virus, varicella-zoster virus, and CMV, but the antibody titers determined by complement fixation and immunofluorescence were normal. CMV, which is not associated with this cancer, could nevertheless favor carcinogenesis in facilitating fusion between epithelial cells and EBV-positive lymphocytes.