Quick Facts
- Sample: Serum
- Fasting: No fasting instructions are specified for this test
- Turnaround: 5-7 business days. May take longer based on weather, holiday, or lab delays.
What This Test Measures
This test measures the avidity of Cytomegalovirus (CMV) IgG antibody in individuals already known to be positive for CMV IgG antibody. Avidity refers to the binding strength between the IgG antibody and the virus, which is reported as a result rather than a simple antibody concentration.
Following primary CMV infection, IgG antibodies initially show low binding strength (low avidity) and mature to high binding strength (high avidity) over a period of 2 to 4 months. This avidity result can help distinguish a recent, primary infection from a past infection, using a serum specimen tested by ELISA methodology.
Benefits
- Helps distinguish recent CMV infection from a past infection
- Uses a single serum sample for avidity testing
- Applies established ELISA methodology
- Supports clinical evaluation of infection timing
- Provides an avidity result for previously CMV IgG positive individuals
Who Is This Test For?
- Pregnant individuals with a known positive CMV IgG result
- Transplant recipients with a known positive CMV IgG result
- Individuals whose healthcare provider needs to clarify infection timing
- Patients being followed for possible recent CMV infection
- Individuals whose provider is managing CMV-related clinical decisions
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What is the purpose of this test?
This test measures the avidity of CMV IgG antibody in people who already have a confirmed positive CMV IgG result. The avidity result may help a healthcare provider evaluate whether a CMV infection is recent (primary) or occurred in the past. It is not a standalone diagnostic test and does not measure other CMV markers.
2. Who would benefit from this test?
This test may be useful for pregnant individuals or transplant recipients who have a known positive CMV IgG result and whose provider wants additional information about the timing of infection. It is intended for use as part of a broader clinical evaluation, not as a standalone screening test.
3. When should I order this test?
You may consider this test if you have a known positive CMV IgG result and your healthcare provider wants to evaluate whether the infection is recent or occurred previously. This is often relevant during pregnancy or in the context of transplant care. Your provider can help determine if this test fits your specific clinical situation.
4. What does this test measure?
This test measures CMV IgG antibody avidity, which reflects the binding strength between the antibody and the virus. The result helps indicate whether IgG antibodies are of low avidity (associated with more recent infection) or high avidity (associated with past infection). It is performed on a serum specimen using ELISA methodology and does not measure IgG concentration or IgM antibody levels.
5. Do I need to fast before this test?
No fasting instructions are specified for this test. No special dietary or fasting preparation is described in the test requirements.
6. How quickly will I get results?
Results for this test are typically available within 5 days. Additional time may be needed if confirmatory or reflex testing is required.
7. How do I interpret the results?
Interpreting CMV IgG avidity results depends on the specific result reported, along with your medical history, pregnancy status or transplant status, and other clinical information. A low avidity result may suggest more recent infection, while a high avidity result may suggest past infection, but neither result alone provides a complete clinical picture. Specimen quality and laboratory methodology can also influence results. Always discuss your results with a qualified healthcare provider who can interpret them in the context of your overall health.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
8. What should I do if my results are abnormal?
If your avidity result suggests a recent or past infection pattern that concerns you, review the results with a qualified healthcare provider. Your provider can help place the result in the context of your health history and determine whether further evaluation is needed. This test does not provide treatment guidance or a complete diagnosis on its own.
9. How often should I get tested?
There is no set testing schedule for CMV IgG avidity testing. Frequency should be determined by your healthcare provider based on your individual clinical situation and monitoring needs, as directed by your healthcare provider.
Pre-test preparation
No special preparation is required.
