Cytomegalovirus Antibodies (IgG, IgM)

Test Code

CPT Codes
86644, 86645

Preferred Specimen
1 mL serum

Minimum Volume
0.4 mL

Transport Container
Plastic screw-cap vial

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Gross lipemia • Plasma • Cord blood

Immunoassay (IA)

False-positive IgM test results may be due to the presence of heterophil antibodies or presence of rheumatoid factor.

Reference Range
Cytomegalovirus Antibody (IgG)
≤0.90 Negative
0.91-1.09 Equivocal
≥1.10 Positive

Cytomegalovirus Antibody (IgM)
≤0.8 No antibody detected
0.9-1.0 Equivocal
≥1.1 Antibody detected

Clinical Significance
Intrauterine or congenital CMV infections occur in 0.5 to 2.2% of all live births. Symptomatic congenital infections usually occur in infants born to nonimmune mothers who have primary infections during pregnancy. Latency and reactivation of CMV influence the interpretation of serological  results. A single positive CMV IgG result is and indication of present or past infection. The presence of CMV IgM suggests a recent CMV exposure but does not differentiate between primary infection and reactivation.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.