Description
QuantiFERON-CMV is an in vitro diagnostic test using a peptide cocktail simulating human CMV proteins to stimulate cells in heparinized whole blood (5). Detection of IFNγ responses by ELISA may indicate CMV immunity.
QuantiFERON-CMV is an in vitro diagnostic test using a peptide cocktail simulating human CMV proteins to stimulate cells in heparinized whole blood. Detection of interferon-gamma (IFNγ) by enzyme-linked immunosorbent assay (ELISA) is used to identify in vitro responses to these peptide antigens that are associated with CMV infection.(1, 5) Loss of this immune function may be associated with development of CMV disease. In a posttransplant setting, patients who have cellular immune response to CMV at the end of prophylaxis have a significantly lower risk of developing CMV disease than those who do not have a detectable immune response. This indicates that QuantiFERON-CMV may predict the development of late-onset CMV disease in transplant recipients (2, 4, 6–9)(see figure "Time to development of CMV disease in patients at the end of prophyplaxis").
QuantiFERON-CMV uses 3 specialized blood collection tubes (Nil, CMV Antigen, Mitogen). The CMV Antigen tubes are coated with peptides that simulate CD8+ specific epitopes of CMV proteins. Stimulation of a patient's T cells with CMV peptides results in the production of IFNγ in infected individuals. A robust IFNγ response in the CMV Antigen tube is indicative of immunity to CMV (see figure "A theorhetical model of QuantiFERON-CMV responses").
Patient blood is collected by venipuncture directly into 3 blood collection tubes (Nil, CMV Antigen, Mitogen) and then incubated for 16 to 24 hours at 37°C. After incubation, plasma is harvested and the ELISA assay is performed to detect human IFNγ, using a standard curve and measurement of optical density. Calculations and test interpretation may be performed manually. QuantiFERON-CMV Analysis software is also available.
