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Cytomegalovirus (CMV) IgG Antibody, Serum

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

This test measures the presence of antibodies to the cytomegalovirus (CMV), a common virus that can affect the immune system. Antibodies indicate past or current infection.

Quick summary

["IgG antibodies to CMV help track exposure and immunity over time."]

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

Key facts at a glance

LOINC
10391-1
Short code
CMV Ig Gvn Vol
Synonyms
CMV Ig Gvn Vol
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 This Test Measures

IgG antibodies are a type of immune protein your body produces in response to CMV. They remain in your system for years after infection, helping your body defend against future exposures. This test helps determine if you’ve been exposed to CMV at any point in your life.

Why It’s Done

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

How It Works

A blood sample is taken and tested for CMV-specific IgG antibodies using an immunoassay method. This detects whether your immune system has ever encountered CMV, regardless of whether you had symptoms.

What to Expect Before or After

No special preparation is needed. A healthcare provider will draw blood from a vein in your arm. Results may take a few days to a week to process. If you’re pregnant, discuss any results with your provider to monitor potential risks to your baby.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results indicate past CMV exposure, which may be important for managing immune conditions, planning pregnancies, or guiding treatment decisions. Negative results suggest no detectable IgG antibodies, meaning you’ve likely never been exposed to CMV or have very low levels. This test alone doesn’t diagnose active infection; other tests (like IgM or viral load) may be needed for that.

Short name

CMV IgG Antibody

Frequently asked questions

What does a positive result mean?
A positive result means your body has produced IgG antibodies to CMV, showing you’ve either had a past infection or been exposed to the virus at some point. This doesn’t mean you’re currently infected, but it confirms your immune system has been activated by CMV.
Can this test detect active CMV infection?
No, this test only detects IgG antibodies, which indicate past exposure. To check for active infection, your provider may order additional tests like CMV IgM antibodies or viral load testing.
Does this test affect my treatment?
Not directly. However, if your test results are relevant to your health condition (e.g., immune status or pregnancy), your provider will use them to guide further care, such as monitoring or preventive measures.
  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