QuantiFERON-CMV is a whole blood interferon-gamma release assay to monitor changes in cell-mediated immunity to cytomegalovirus (CMV). CMV is the most common and problematic viral infection in solid organ transplant recipients. Find out how QuantiFERON-CMV may help you identify transplant patients at most risk of new and recurrent CMV disease.
QF-CMV is not a direct test determining CMV infection and should not solely be used to exclude CMV infection.
Which transplant patients are at risk of CMV disease post-prophylaxis?
Current Immunosuppressive therapies used to prevent the rejection of a transplanted organ have detrimental effects on the T-lymphocytes and cell-mediated immune responses in solid organ transplant recipients. These patients have an increased susceptibility to viral infections post-transplant (2, 3). Approximately half of these patients show signs of active Cytomegalovirus (CMV) infection (i.e., viral replication) after completion of prophylaxis (1).
Consequently, CMV-associated morbidity and mortality in transplant recipients are very high (3–5). Infection can result not only in organ-specific conditions affecting the brain, lungs, and liver, but also in opportunistic infections, increased allograft rejection, and patient death. These CMV-related complications add an estimated 49% to the cost of transplant care (6).
The immune status of the transplant recipient can influence the (re)activation of CMV in transplant recipients. A specific cytokine marker for cellular immune responses, interferon-gamma (IFN-γ) plays a key role (7, 8). Secreted from CMVspecific T-cells in response to antigens associated with CMV infection (8, 9), IFN-γ levels may indicate a patient’s overall level of cell-mediated immunity.
Cytomegalovirus (CMV) is the most common and problematic viral infection in solid organ transplant recipients.
How can QuantiFERON-CMV help identify at-risk patients?
QuantiFERON-CMV uses specialized blood collection tubes that are coated with peptides simulating CD8+-specific epitopes of CMV proteins, along with negative and positive control tubes. Stimulation of CD8+ T-cells in 1ml of whole blood with the CMV peptides results in the production of IFN-γ in infected individuals. An enzyme-linked immunosorbent assay (ELISA) is then used to measure the amount of IFN-γ present in plasma from each of the 3 tubes (Nil control, CMV Antigen, and Mitogen control). A robust IFN-γ response in the CMV Antigen tube is indicative of immunity to CMV (11).
Patients who have a 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 (8, 10–13).
Patients with a reactive QuantiFERON-CMV result remain free from CMV disease significantly more often and for longer than patients with a non-reactive QuantiFERON-CMV result after cessation of antiviral prophylaxis.
QuantiFERON-CMV may assist your ability to (13):
QuantiFERON-CMV Test is not a direct test for determining CMV infection and should not solely be used to exclude CMV infection.
The accuracy, efficacy, and utility of QuantiFERON-CMV for monitoring CMV-related changes in cell-mediated immunity has been demonstrated in multiple studies (8, 10–13).
The International Consensus Guidelines on the Management of Cytomegalovirus in Solid-Organ Transplantation (14) suggest that an ideal immune monitoring assay should:
QuantiFERON-CMV meets virtually all the criteria specified by the guidelines above and is the only standardized, commercially-available immune monitoring assay that is specific for CMV (14).
Studies now highlight that monitoring a patient’s level of cellular immunity to CMV using QuantiFERON-CMV could help guide the optimal duration of costly antiviral therapy in high-risk patients (8, 10, 11, 13–16).
QuantiFERON Technology is a unique approach to disease detection and monitoring - the only in vitro diagnostic technology available for detection of cell-mediated immune responses from whole blood samples
Individuals exposed to CMV and other diseases have specific T-cell lymphocytes in their blood. These T-cells are a memory bank of an individual’s immune system, recognizing antigens to which the T-cells have been previously exposed. When a disease-specific antigen is combined with the blood of an individual who has been exposed to that disease, a rapid restimulation of the T-cells with specific memory of that antigen occurs. These antigen-specific T-cells respond by secreting IFN-γ, which can be measured as a specific marker of immune response against that disease antigen.
Figure 3. QuantiFERON-CMV process
QuantiFERON-CMV is not US FDA-approved and is limited to research use only in the United States.
QuantiFERON-CMV is CE Marked for commercial use in Europe.
1. Paya, C. et al. (2004) Am. J. Transpl. 4, 611. 2. Smyth, R.L. et al. (1991) Transplantation 52, 480. 3. Boeckh, M. and Nichols, W.G. (2003) Herpes 10, 12. 4. Gandhi, M.K. and Khanna, R. (2004) Lancet Infect. Dis. 4, 725. 5. Humar, A., Gillingham, K., Payne, W.D., Sutherland, D.E. and Matas, A.J. (2000) Transplantation 70, 310. 6. Kim, W.R. et al. (2000) Transplantation 69, 357. 7. Sylwester, A.W. et al. (2005) J. Exp. Med. 202, 673. 8. Walker, S. et al. (2007) Transpl. Infect. Dis. 9, 165. 9. Westall, G. Kotsimbos, T. and Brooks, A. (2006) Am. J. Transpl. 6, 577. 10. Westall, G.P., Mifsud, N.A. and Kotsimbos, T. (2008) Am. J. Transpl. 8, 1749. 11. Kumar, D. et al. (2009) Am. J. Transpl. 9, 1214. 12. Singh, N.J. (2006) Clin. Virol. 35, 474. 13. Danziger-Isakov, L.A. et al. (2003) Transplantation 75, 1538. 14. Kotton, C.N. et al. (2013) Transplantation 96, 333. 15. Danziger-Isakov, L. and Heeger, P.S. (2009) Am J Transpl 9, 987. 16. Crough, T. and Khanna, R. (2009) Clin Micro Reviews 22, 76. Antigen presenting cell (APC)
QuantiFERON-CMV is not US FDA-approved and is not available in the United States
QuantiFERON-CMV is CE marked for commercial use in Europe.