Cytomegalovirus antigenemia assay: therapeutic usefulness and biological significance.

The cytomegalovirus antigenemia test is based on immunocytochemical detection of HCMV early structural protein pp65 in the nuclei of polymorphonuclear blood leucocytes of patients with systemic infection. Specificity and sensitivity are > or = 90% and positivity correlates well with HCMV disease, allowing better monitoring than isolation from buffy coat of patients undergoing chemotherapy. Polymorphonuclear cells appear as a main site of initial HCMV infection and reactivation.