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Background: Presently the semiquantitative pp65 cytomegalovirus (CMV) antigenemia test on white blood cells is often used for monitoring transplant patients for the appearance of active CMV infections. However, the need for immediate processing of the specimens and the lack of interlaboratory standardization of the test may sometimes be a disadvantage. Objective: The aim of this study was to investigate the value of the recently developed second version of the Murex Hybrid Capture(TM) (MHC) CMV-DNA assay (v 2.0) in comparison with the CMV-pp65 test. The MHC CMV-DNA assay is a quantitative solution hybridization antibody capture assay, using alkaline phosphatase conjugated antibodies and a chemiluminescent substrate. Study design: 248 EDTA blood samples from 33 renal transplant patients and 32 samples from 22 other immunocompromised patients were tested by both the MHC CMV-DNA assay and the CMV-pp65 test. Results: The qualitative (+ or -) results of both tests showed an overall concordance of 81.4%,. Calculations on the basis of discordancy analyses showed that the sensitivity, the specificity, and the positive and negative predictive values were 87.7 98.3, 98.6, 85.2% for the MHC CMV-DNA assay and 76.6, 100, 100, 75.5% for the CMV-pp65 test. Comparison of the quantitative results of both tests systems showed a correlation coefficient of 0.837. In addition, retesting of 50 samples with the MHC-CMV-DNA assay showed an excellent reproducibility with a correlation coefficient of 0.992. All patients which were tested regularly (at least five samples) became either positive with both tests or with none of them. Neither test system detected CMV significantly earlier than the other one. Both tests became strongly positive in all transplant patients with symptomatic CMV infections, and both tests showed a rapid decline of CMV during subsequent antiviral treatment. Conclusion: The quantitative Murex Hybrid Capture(TM) CMV-DNA assay (v 2.0) may become a valuable additional tool in CMV diagnosis. Further studies will be needed to support this preliminary judgement. (C) 1999 Elsevier Science B.V. All rights reserved.

In 10 of 14 patients with an active cytomegalovirus (CMV) infection, distinctive large cells (35-45 microns in diameter) were present in the peripheral blood. Morphologically these cells closely resembled the classic cytomegalic inclusion cells, generally regarded as a diagnostic hallmark of CMV infection. Moreover, these cells were shown to express CMV antigens belonging to all three stages of the viral replication cycle, indicating a productive CMV infection. In addition, immunologic staining with monoclonal antibodies directed against cell differentiation and marker proteins showed that these circulating cytomegalic cells were of endothelial origin. The presence of CMV-infected endothelial cells in the peripheral blood of patients with an active CMV infection indicates that such an infection might be accompanied by widespread occult vascular damage.

We describe enhanced expression and enzymatic activity of ecto-ATPase and ecto-5' nucleotidase on CMV infected endothelial cells as compared to uninfected cells, These ectoenzymes play a major role in modulation of platelet activation and aggregation. Furthermore, adenosine has a modulatory effect upon inflammation. Addition of ATP, ADP or AMP to cultures of CMV infected or uninfected endothelial cells revealed increased turnover of AMP in CMV infected endothelial cells. in addition, the superoxide production by stimulated polymorphonuclear cells was inhibited in the presence of CMV infected endothelial cells as compared to uninfected cells, probably due to the enhanced activity of ecto-5'-nucleotidase and associated to production of adenosine. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.