CYTOMEGALOVIRUS (CMV) ANTIBODIES, IgG & IgM, SERUM

 

 

Synonyms:

 

Lab Test Code:

VISCMP

Test Performed In:

Microbiology

Test Methodology:

Enzyme Immunoassay

Reported:

2-8 Days

Test Set Up Frequency:

IgG:  Twice a week

IgM:  Once a week

Patient Preparation:

 

Specimen Requirements:

Collect: 4 mL blood in gold-top tube

Transport: Refrigerated

Minimum volume: 1 mL (pediatric 0.2 mL) of serum

Rejection Criteria: Contaminated, hemolyzed, or heat-inactivated specimens.

Specimen Stability: After separation from cells: Ambient: 8 hours, Refrigerated: 48 hours, Frozen: 1 year

Reference Values:

Cytomegalovirus IgG

< 0.90               Negative

0.90 to 1.09      Equivocal

> 1.09               Positive

Positive IgG results, in the absence of IgM antibodies, most often are indicative of past Cytomegalovirus (CMV) infection and do not necessarily assure protection from future infection with CMV.  Patients with systemic lupus erythematosus may give false positive results.  Positive CMV titers from maternal antibody can persist in neonates for up to 6 months.  Negative results indicate no significant level of detectable antibodies to CMV.  In neonates, a negative result may help to exclude congenital infection.  Since a single specimen cannot determine a recent infection, paired specimens, acute and convalescent, should be tested concurrently to demonstrate sero-conversion.  Patients with negative or equivocal results, if clinically indicated, should be retested in 2 to 4 weeks.

Cytomegalovirus IgM

< 0.91               Negative

0.91 to 1.09      Equivocal

> 1.09               Positive

Positive IgM results to Cytomegalovirus (CMV) are indicative of a primary or recurrent infection. IgM antibodies to CMV can persist for 2 to 9 months after the initial infection. Not all patients with reactivated CMV infection will have detectable levels of IgM antibodies. Positive IgM results in neonate have a high probability of being an indication of congenital or neonatal infection. Patients infected with Epstein-Barr virus may give false positive results.  A negative result indicates no significant level of detectable antibodies to CMV but does not exclude a primary or a recurrent infection.  Immunocompromised patients may give a false negative result during an active infection.  Patients with negative and equivocal results, if clinically indicated, should be retested in 7 days.

Additional Information:

 

CPT Code(s):

86644, 86645