Cytomegalovirus (CMV) IgG Antibody, Serum/Plasma
This test measures your body’s immune response to the cytomegalovirus (CMV), a common virus that can affect anyone but is more likely to cause problems in people with weakened immune systems.
["Knowing your CMV IgG status helps determine past exposure and immune protection status."]
Key facts at a glance
- LOINC
- 6921-1
- Short code
- CMV IgG CSF IA-aCnc
- Synonyms
- CMV IgG CSF IA-aCnc
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- CPT
- 82784
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have a weakened immune system (e.g., due to HIV, chemotherapy, or organ transplant), are pregnant, or have symptoms like fever, fatigue, or organ damage that could suggest CMV infection. It may also be used to monitor immune function or guide treatment decisions.
What to Expect Before the Test
No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. The test is quick and typically done in a clinic or lab setting. If you’re pregnant or have a bleeding disorder, let your provider know before the test.
What the Results Mean
A positive result means your body has produced antibodies against CMV, indicating past infection. This doesn’t always mean you’re currently infected but suggests your immune system has been exposed. A negative result means you likely haven’t been exposed or have very low antibody levels.
Common Reasons for Testing
This test is often used to assess immune health, diagnose or monitor CMV-related conditions, or evaluate risk in high-risk groups (e.g., transplant recipients, newborns of infected mothers). It’s not typically used to diagnose active CMV infection, which would require additional tests.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
CMV IgG antibodies are important for determining long-term immunity and guiding preventive measures. For example, in transplant patients, knowing your status helps prevent CMV disease, which can be severe. In pregnant women, a positive result may prompt further testing to assess risk to the baby. Results don’t replace other diagnostic tools but provide critical context for treatment planning.
Short name
CMV IgG Antibody
Frequently asked questions
What does a positive result mean?
Can I get CMV if my IgG test is negative?
How often should I get this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy