CMV IgG Antibody Detection
Label Mnemonic: CMVG
Epic Lab Code: LAB937
Downtime Form: A-1a General Laboratory Requisition
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3.0 mL whole blood from light green top tube or TWO Microtainer® devices.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
3 hours (upon receipt in laboratory)
Reference Range:
Reference range and methodology changed effective 12/11/2012.

0.8 AI or less: Negative - No significant level of detectable CMV IgG antibody.

0.9-1.0 AI: Equivocal - Repeat testing in 10-14 days may be helpful.

1.1 AI or greater: Positive - IgG antibody to CMV detected, which may indicate a current or past CMV infection.
Comments:
The best evidence for current infection is a significant change on two appropriately timed specimens, where both tests are done in the same laboratory at the same time.
Test Limitations:
Sera collected very early in the acute stage of disease may have undetectable IgG levels. In immunocompromised patients, CMV serology (IgG or IgM antibody titers) may not be reliable and may be misleading in the diagnosis of acute or reactivation CMV disease. Positive results from cord blood should be interpreted with caution. The presence of IgG CMV antibodies in cord blood is usually the result of passive transfer from mother to the fetus. A negative test, however, may be useful in excluding current infection, but the most definitive diagnosis of CMV infection requires viral culture. Positive test results may not be valid in persons who have received blood transfusions or other blood products within the past several months. Lack of significant increase in antibody level does not exclude the possibility of CMV infection.
Methodology:
Multiplex Flow Immunoassay
CPT Code:
86644