The study of cytopathological aspects induced by human cytomegalovirus infection

In cytological examination, human cytomegalovirus (HCMV) infection can not be implied unless typical HCMV-infected cells like owl's-eye cells are present. However, such cells are not always observed in HCMV-infection cases. The aim of our study is to establish the cytopathological features induced by HCMV. In vitro transfection and fluorescence in situ hybridization (FISH) were performed on human embryo lung (HEL) cells. Marked cellular aggregation was observed at 6-hr postinfection (hpi). Multinucleated cells, giant cells, and, particularly, small vacuoles were present in the nuclei or cytoplasm before the appearance of inclusion bodies. However, molding and ground glass in nuclei were absent. Cell clusters displayed round cytoplasm, dispersed later, and showed anisocytosis. All features occurred before 48 hpi when the owl's-eye cell appeared. In FISH, the positive signal highlighted viral particles that became predominant and localized in nuclei. These cytological aspects are dependent on viral replication and contribute to the cytological detection of HCMV infection.