Cytomegalovirus Infections in Humans

Paul D Griffiths, Royal Free and University College Medical School, London, UK

Published online: April 2010

DOI: 10.1002/9780470015902.a0002227.pub2

Cytomegalovirus (CMV) is a herpesvirus that causes severe disease in the immunocompromised because virus replication is normally held in check by cell-mediated immune responses. Patients receiving immunosuppressive drugs to allow allo-transplantation, patients with AIDS (acquired immunodeficiency syndrome) or fetuses with immature immune responses are therefore at risk of developing CMV end-organ disease. A high viral load is required for CMV end-organ disease to develop. Ganciclovir is a potent inhibitor of CMV replication and can be used either for prophylaxis or for preemptive therapy (administering the drug when CMV is detected in the blood). Both of these strategies effectively control CMV end-organ disease in transplant patients. A phase II study of a prototype CMV vaccine has recently published encouraging results, suggesting that CMV infection may ultimately be preventable by means of universal immunisation.

Key Concepts:

  • CMV viraemia precedes CMV end-organ disease.
  • Prompt treatment of CMV viraemia prevents end-organ disease.
  • The probability of end-organ disease is nonlinear with respect to viral load.
  • This threshold relationship is seen also in babies with congenital CMV infection and hearing loss.
  • Prompt treatment of congenital CMV infection can reduce the risk of progressive hearing loss.

Keywords: cytomegalovirus; viral load; threshold; dynamics; indirect effects

Figure 1. Intracellular pathways leading to presentation of cytomegalovirus (CMV) peptide epitopes at the plasma membrane by HLA class I molecules. ER, endoplasmic reticulum; PM, plasma membrane; PRO, proteasome; RIB, ribosome; TAP, transporter associated with antigen presentation; TGN, trans-Golgi network and V, virus-encoded protein. Letters and numbers indicate CMV proteins which can interfere with antigen presentation (as discussed in the text).
Figure 2. Probability of disease with increased augmented methylprednisolone: cumulative probability of symptomatic disease according to viral load and methylprednisolone usage (Cope et al., 1997a). Methylprednisolone usage: no drug given, blue line; one course, red line; two courses, green line; three courses, yellow line and four courses, purple line. One course consists of 1 g a day for 3 days.
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 Further Reading
    book Britt WJ and Alford A (1996) "Cytomegalovirus". In: Editors-in-Chief: Fields BN, Knipe DM and Howley PM; Associate editors: Chanock RM, Monath TP, Melnick JL and Roizman B Fields Virology, 3rd edn, vol. 2, pp. 2493–2524. Philadelphia: Lippincott-Raven.
    book Griffiths PD and Emery VC (1997) "Cytomegalovirus". In: Richman DD, Whitley RJ and Hayden FG (eds) Clinical Virology, pp. 445–470. New York: Churchill Livingstone.
    book Mocarski ESJ (1996) "Cytomegalovirus and their replication". In: Editors-in-Chief: Fields BN, Knipe DM and Howley PM; Associate editors: Chanock RM, Monath TP, Melnick JL and Roizman B Fields Virology, 3rd edn, vol. 2, pp. 2447–2492. Philadelphia: Lippincott-Raven.
    Riddell SR and Greenberg PD (1997) T cell therapy of human CMV and EBV infection in immunocompromised hosts. Reviews in Medical Virology 7: 181–192.
    book Roizman R (1996) "Cytomegalovirus and their replication". In: Editors-in-Chief: Fields BN, Knipe DM and Howley PM; Associate editors: Chanock RM, Monath TP, Melnick JL and Roizman B Fields Virology, 3rd edn, vol. 2, pp. 2221–2230. Philadelphia: Lippincott-Raven.
    Umene K (1999) Mechanism and application of genetic recombination in herpesviruses. Reviews in Medical Virology 9: 171–182.

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Immunodeficiency | Virus Diseases
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Article Title: Cytomegalovirus Infections in Humans
 
How to Cite close
Griffiths, Paul D(Apr 2010) Cytomegalovirus Infections in Humans. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0002227.pub2]