[Virologic analysis of 1,000 blood samples processed for cytomegalovirus isolation (viremia) and pp65 antigenemia in immunodepressed patients]

BACKGROUND: To study the principal virological aspects of 1,000 blood samples processed for cytomegalovirus (CMV) isolation (viremia) and pp65 antigenemia assay in immunosuppressed patients, and to compare the diagnostic efficacy of both technics. PATIENTS AND METHODS: All the blood samples collected with EDTA, were fraccionated by dextran sedimentation. The polymorfonuclear rich fraction was used for the isolation of CMV by the shell-vial cell culture and the pp65 antigenemia assay. The cell cultures were stained at 18-24 hours with a monoclonal antibody against p72 CMV antigen. RESULTS: The 1,000 blood samples studied belonged to 363 patients (299 infected by the HIV, 49 renal transplant recipients, and 15 patients with haematologic diseases). 78 patients (21.4%) developed a CMV infection and/or disease. The overall results obtained in the comparative study for the CMV detection in peripheral blood were 86.7% for the antigenemia assay and 58.5% for the shell-vial culture (p = 0.0001). Of 49 patients with renal transplant, 20 (40.8%) presented with a CMV infection versus 19.3% in the HIV-positive group. The transplant recipient patients presented most frequently positivity for both diagnostic technics, and the HIV-positive patients a higher percentage of antigenemia-positive with culture negative. The shell-vial culture (viremia) had most diagnostic efficacy in the transplant recipients group. CONCLUSIONS: In the immunosuppressed patients the pp65 antigenemia assay has demonstrated a high diagnostic efficacy for CMV detection in peripheral blood. However because the antigenemia not always correlates with a replicative viral load, it is necessary to routinely perform culture of the blood in a cell culture system, preferently by the shell-vial method, because this system allows to make the diagnosis of CMV infection in a short period of time.