Epstein-Barr virus (EBV) in infectious mononucleosis: detection of the virus in tonsillar B lymphocytes but not in desquamated oropharyngeal epithelial cells

Aims-Despite its well established tropism for B cells, the nature of the ce llular compartment(s) mediating primary and persistent Epstein-Barr virus ( EBV) infection is still a matter of controversy. In view of the association of EBV with several lymphoid and epithelial malignancies, resolution of th is issue is important. Methods-Desquamated oropharyngeal epithelial cells from 10 patients with ac ute infectious mononucleosis and from seven chronic virus carriers were stu died for evidence of EBV infection using in situ hybridisation for the dete ction of the small EBV encoded RNAs (EBERs) and of the viral genome. In add ition, immunocytochemistry was used to detect the BZLF1 transactivator prot ein of EBV. Results-There was no evidence of latent or replicative EBV infection in oro pharyngeal epithelial cells in any of the samples. In contrast, EBV infecte d B cells were readily identified in a tonsil from a patient with infectiou s mononucleosis. Conclusions-The results suggest that oropharyngeal epithelial cells are not a major site of EBV infection and provide further support for the notion t hat B cells mediate primary and persistent EBV infection.