CIRCULATING ENDOTHELIAL GIANT-CELLS PERMISSIVE FOR HUMAN CYTOMEGALOVIRUS (HCMV) ARE DETECTED IN DISSEMINATED HCMV INFECTIONS WITH ORGAN INVOLVEMENT

Giant cells fully permissive for human cvtomegalovirus (HCMV) were fou nd to circulate, at a variable proportion, in peripheral blood of 21 o ut of 25 immunocompromised patients with disseminated HCMV infection. Circulating endothelial giant cells (EGC) were identified by a specifi c monoclonal antibody of endothelial origin and shown to express immed iate-early, early, and late viral proteins. Immunostaining patterns of different viral proteins were comparable to those detected in vitro i n cultured human umbilical vein endothelial cells. EGC counts > 10 wer e associated with high levels (> 100) of HCMV viremia and antigenemia, as well as with an overt clinical syndrome in transplanted patients, and to an untreated long lasting organ localization in AIDS patients. On the other hand, EGC counts were < 10 during disseminated HCMV infec tions of both transplant recipients with no apparent organ syndrome an d AIDS patients with recent organ involvement. In tissue sections from AIDS patients, infected endothelial cells were found to progressively enlarge till detaching from the small vessel wall and entering blood stream. HCMV-infected EGC represent a new systemic parameter suitable for the diagnosis of HCMV organ involvement and for the study of the p athogenesis of disseminated infections.