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Cytomegalovirus (CMV) IgG Antibody, Serum/Plasma

Published: August 9, 2026Updated: August 16, 2026

This test measures antibodies to the cytomegalovirus (CMV), a common virus that can affect the immune system. It helps determine past exposure to CMV.

Quick summary

["Past CMV infection status detected by antibody presence."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
22244-8
Short code
CMV IgG SerPl Ql
Synonyms
CMV IgG SerPl Ql
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does This Test Measure?

The CMV IgG antibody test looks for specific proteins (antibodies) your immune system produces in response to having been exposed to CMV. If antibodies are found, it suggests you’ve had CMV at some point, even if you don’t currently have symptoms.

Why Might You Need This Test?

Doctors may order this test to check for past CMV infection in people with weakened immune systems (e.g., after organ transplant, chemotherapy, or HIV), pregnant individuals (to assess risk to the baby), or those with unexplained symptoms like fatigue or organ issues that could be linked to CMV.

What Could This Result Mean?

A positive result (antibody detected) means you’ve likely had CMV before. A negative result suggests no detectable antibodies, meaning either you’ve never been exposed or the test was taken too soon after exposure. Results don’t indicate current infection status.

How Is This Test Done?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where antibodies are tested using an immunoassay method to detect their presence.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CMV IgG antibodies are important for monitoring immune health, especially in high-risk groups. For example, in transplant patients, knowing past exposure helps guide prevention strategies. In pregnancy, it can help assess CMV risk to the fetus, though it doesn’t replace other tests like CMV PCR for active infection.

Short name

CMV IgG Antibody

Frequently asked questions

What does a positive CMV IgG result mean for my health?
A positive result means you’ve had CMV before, which is common. It doesn’t indicate whether you’re currently infected or if you’ll develop symptoms. Your doctor may still recommend other tests (like CMV PCR) if you have symptoms or a weakened immune system.
Can I get CMV if I have positive CMV IgG antibodies?
Yes, you can still get CMV even if you’ve had it before. Antibodies protect against severe illness but don’t prevent reinfection. If you’re at high risk (e.g., transplant recipient), your doctor may focus on preventing new infections.
How soon after exposure can I expect to get positive CMV IgG antibodies?
Antibodies typically appear within weeks to months after initial infection. If you’re tested too soon (e.g., within 2–4 weeks), you might get a negative result even if you’ve been exposed. Your doctor may recommend retesting later.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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