Histopathological detection of owl's eye inclusions is still specific for cytomegalovirus in the era of human herpesviruses 6 and 7

Background-Cytomegalovirus (CMV) is the prototype member of the beta-herpes virinae, which can cause multiple organ dysfunction in the immunocompromise d host. Human herpesvirus 6 (HHV-6) and HHV-7 are newer members of the beta -herpesvirinae that can cause febrile illness in young children and are als o possible pathogens in the immunocompromised patient. Aim-CMV is detected in histopathological sections by visualisation of owl's eye inclusion bodies. The aim of this study was to quantify the relation b etween CMV, HHV-6, and HHV-7 viral loads and the presence of owl's eye incl usions in histological sections. Methods-Histopathological examination of postmortem material and recording of owl's eye inclusion bodies were performed. CMV, HHV-6, and HHV-7 were de tected by qualitative and quantitative polymerase chain reaction (PCR) from the same postmortem samples. Statistical analysis of the histopathological and PCR results was performed. Results-There was a significant association between the detection of owl's eye inclusion bodies and positive CMV PCR (p < 0.001); the median CMV viral load was significantly higher in samples that were positive for owl's eye inclusions (p < 0.001). No association was found between the presence of ow l's eye inclusions and HHV-6 or HHV-7 positivity. Conclusion-Histological detection of owl's eye inclusion bodies is an insen sitive but highly specific method for detecting CMV organ involvement. Owl' s eye inclusion bodies are not associated with HHV-6 or HHV-7 infection.