Test Catalog

Test ID: CMVP    
Cytomegalovirus (CMV) Antibodies, IgM and IgG, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Aiding in the diagnosis of acute or past infection with cytomegalovirus (CMV)


Determination of prior exposure to CMV


This test should not be used for screening blood or plasma donors.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Cytomegalovirus (CMV) is a member of the Herpesviridae family of viruses and usually causes asymptomatic infection after which it remains latent in patients, primarily within bone marrow derived cells. Primary CMV infection in immunocompetent individuals may manifest as a mononucleosis-type syndrome, similar to primary Epstein-Barr virus infection, with fever, malaise and lymphadenopathy.


CMV is a significant cause of morbidity and mortality among bone marrow or solid organ transplant recipients, individuals with AIDS, and other immunosuppressed patients due to virus reactivation or from a newly acquired infection. Infection in these patient populations can affect almost any organ and lead to multiorgan failure. CMV is also responsible for congenital disease among newborns and is one of the TORCH infections (toxoplasmosis, other infections including syphilis, rubella, CMV, and herpes simplex virus).


CMV seroprevalence increases with age. In the United States, the prevalence of CMV-specific antibodies increases from approximately 36% to over 91% in children between 6 to 11 years of age and adults over 80 years old, respectively.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.







Reference values apply to all ages.

Interpretation Provides information to assist in interpretation of the test results


A negative cytomegalovirus (CMV) IgM result suggests that the patient is not experiencing acute or active infection. However, a negative result does not rule-out primary CMV infection.


It has been reported that CMV-specific IgM antibodies were not detectable in 10% to 30% of cord blood sera from infants demonstrating infection in the first week of life. In addition, up to 23% (3/13) of pregnant women with primary CMV infection did not demonstrate detectable CMV IgM responses within 8 weeks postinfection. In cases of primary infection where the time of seroconversion is not well defined as high as 28% (10/36) of pregnant women did not demonstrate CMV IgM antibody.


Positive CMV IgM results indicate a recent infection (primary, reactivation, or reinfection). IgM antibody responses in secondary (reactivation) CMV infections have been demonstrated in some CMV mononucleosis patients, in a few pregnant women, and in renal and cardiac transplant patients. Levels of antibody may be lower in transplant patients with secondary rather than primary infections.



Positive CMV IgG results indicate past or recent CMV infection. These individuals may transmit CMV to susceptible individuals through blood and tissue products.


Individuals with negative CMV IgG results are presumed to not have had prior exposure or infection with CMV and are, therefore, considered susceptible to primary infection.


Equivocal CMV IgM or IgG results may occur during acute infection or may be due to nonspecific binding reactions. Submit an additional sample for testing if clinically indicated.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Sera drawn very early during the acute stage of infection may have undetectable levels of cytomegalovirus (CMV) IgM or IgG.


Immunocompromised patients may have impaired immune responses and non-reactive IgM/IgG results may be due to delayed seroconversion and, therefore, do not rule out current infection.


The CMV IgM and IgG results should not be used alone to diagnose CMV infection. Results should be considered in conjunction with clinical presentation, patient history and other laboratory findings. In cases of suspected disease, submit a second sample for testing in 10 to 14 days.


The performance characteristics of these assays have not been evaluated in immunosuppressed or organ transplant recipients and have not been established for cord blood or for testing of neonates.


Immune complexes or other immunoglobulin aggregates present in patient samples may cause increased nonspecific binding and produce false-positive results.


Potential cross-reactivity for CMV IgM may occur with specimens positive for Epstein-Barr virus viral capsid antigen IgM and parvovirus B19 IgM.


Potential cross-reactivity for CMV IgG with human chorionic gonadotropin, HIV IgG, multiple myeloma IgG, rheumatoid factor IgM, and Toxoplasma gondii IgG have not be ruled out.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Soderberg-Naucler C, Fish NK, Nelson JA: Reactivation of latent human cytomegalovirus by allogeneic stimulation of blood cells from healthy donors. Cell. 1997 Oct 3;91(1):119-126

2. Bruminhent J, Thongprayoon C, Dierkhising RA, Kremers WK, Theel ES, Razonable RR: Risk factors for cytomegalovirus reactivation after liver transplantation: can pre-transplant cytomegalovirus antibody titers predict outcome? Liver Transpl. 2015;21(4):539-546

3. Dioverti MV, Razonable RR: Cytomegalovirus. Microbiol Spectr. 2016;4(4)

4. Staras SA, Dollard SC, Radford KW, Flanders WD, Pass RF, Cannon MJ: Seroprevalence of cytomegalovirus infection in the United States, 1998-1994. Clin Infect Dis. 2006;43(9):1143