Early virus isolation, early structural antigen detection and DNA amplification by the polymerase chain reaction in polymorphonuclear leukocytes from AIDS patients with human cytomegalovirus viraemia.

Fifty AIDS patients were investigated for human cytomegalovirus (HCMV) viraemia when potentially HCMV-related clinical symptoms or syndromes were observed. Nine patients underwent prolonged virologic follow-up, while 41 additional patients were examined only once or sporadically. Concentrated preparations of polymorphonuclear leukocytes (PMNL) from 153 blood samples were obtained for monitoring: (1) early virus isolation in cell cultures 24 h p.i. (viraemia); (2) early structural antigen detection in cytospin preparations (antigenemia); and (3) HCMV DNA in blood (DNAemia) through DNA amplification by the polymerase chain reaction (PCR). Viraemia and antigenemia were quantitated, whereas evaluation of DNAemia was only qualitative. A good correlation between levels of viraemia and antigenemia was consistently found except during ganciclovir treatment. HCMV-related clinical symptoms were observed when the number of infected PMNL was greater than 100 per 2 x 10(5) cells examined. All 56 blood samples positive for viraemia and antigenemia were also PCR-positive, whereas 44 samples (39 of which taken from patients with ascertained HCMV infection in blood) were positive by PCR only. Viraemia and antigenemia were often unrelated to HCMV organ syndromes, such as retinitis, in which only DNAemia was often detected. Prolonged ganciclovir treatment kept viraemia, antigenemia and even DNAemia at a low or negative level, yet drug discontinuation led to rapid progression of HCMV infection in blood. In addition, prolonged antiviral treatment could induce appearance of ganciclovir-resistant HCMV strains, requiring alternative foscarnet therapy. In conclusion, determination of viraemia and antigenemia appears essential for correct clinical management and antiviral treatment of disseminated HCMV infections in AIDS patients. However, PCR is the most sensitive method for diagnosis and monitoring of HCMV infections in blood at a pre-clinical stage.