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Cytomegalovirus (CMV) IgG Antibody, Serum (Viral Immunoglobulin G)

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

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

Quick summary

["This test helps determine if you’ve been exposed to CMV or if your immune system has developed immunity over time."]

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

Key facts at a glance

LOINC
108748-5
Short code
CMV IgG Avidity Msmt SerPl
Synonyms
CMV IgG Avidity Msmt SerPl
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

Why This Test Is Done

Doctors may order this test to evaluate exposure to CMV, assess immune function, or diagnose conditions like HIV or organ transplant rejection. It can also help monitor immune response in certain chronic illnesses.

What to Expect Before the Test

No special preparation is needed. A blood sample is drawn from a vein, typically in your arm. You may feel a slight pinch, but it usually takes only a few minutes.

What the Results Mean

Positive results suggest you have developed antibodies against CMV, meaning you’ve likely been exposed to the virus at some point. Negative results indicate no detectable antibodies, which may mean you’ve never been exposed or the test was taken too early after exposure.

Common Uses of This Test

This test is often used in people with weakened immune systems (e.g., those with HIV/AIDS, undergoing chemotherapy, or after organ transplants) to track CMV infection risk or monitor immune health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

CMV can cause serious infections in people with compromised immune systems. Detecting IgG antibodies helps identify past exposure, which can inform preventive strategies or treatment decisions. In transplant patients, monitoring CMV status is critical to avoid complications from reactivation of the virus.

Short name

CMV IgG Antibody

Frequently asked questions

How long does it take to get the results of this test?
Results are typically available within 1 to 3 business days, depending on your lab’s processing schedule. Follow-up with your healthcare provider to discuss the meaning of your results.
What does a positive CMV IgG result mean for my health?
A positive result means you have developed immunity to CMV through past infection. This does not indicate an active infection but confirms your body has mounted an immune response. If you have a weakened immune system, this may help guide preventive measures or monitoring plans.
Can I have false-negative results from this test?
Yes, it’s possible to have a false-negative result if the test was taken too early after exposure, before your body produces detectable antibodies. If you suspect recent exposure, retesting may be recommended.
  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