Cytomegalovirus (CMV) Avidity IgG

• Test Name: Cytomegalovirus (CMV) Avidity IgG
• Test Type: Serological test
• Specimen Required: Blood sample (serum)
• Methodology: Enzyme-linked immunosorbent assay (ELISA) or chemiluminescent immunoassay (CLIA)
• Purpose: Determines the avidity (binding strength) of CMV-specific IgG antibodies to distinguish between recent and past infections.

• Primary Use: Differentiates between recent primary CMV infection and past infection, especially in pregnant women to assess the risk of transmission to the fetus.
• Pregnancy Monitoring: Helps in evaluating the risk of congenital CMV infection in pregnant women who test positive for CMV IgG.
• Immunocompromised Patients: Assesses the risk of reactivation or recent infection in immunocompromised patients, such as organ transplant recipients.

• IgG Avidity Index: Measures the strength of the binding between IgG antibodies and the CMV antigen.
• Avidity Interpretation: Provides a numerical index that helps classify the infection as recent or past.

• Low Avidity: Suggests a recent CMV infection, typically within the past 2-3 months.
• High Avidity: Indicates a past infection, usually older than 3-4 months.
• Intermediate Avidity: This may require additional testing or clinical correlation to determine the timing of the infection.
• Clinical Implications: Low avidity in early pregnancy may indicate a higher risk for congenital CMV infection.

• Qualitative and Quantitative: Results are reported as an avidity index, with ranges typically indicating low, intermediate, or high avidity.
• Turnaround Time: Results are usually available within a few days.
• Reporting: The report includes the avidity index with an interpretation of whether the infection is recent or past, aiding in clinical decision-making.

Q. What is the Cytomegalovirus (CMV) Avidity IgG Test?
The CMV Avidity IgG test measures the strength of the binding of CMV-specific IgG antibodies to determine whether a CMV infection is recent or has occurred in the past
 

Q. Why is the CMV Avidity IgG Test important during pregnancy?
It is used to assess the risk of congenital CMV infection in the fetus by determining if a pregnant woman has had a recent primary infection
 

Q. How is the CMV Avidity IgG Test different from a standard CMV IgG test?
While a standard CMV IgG test detects the presence of antibodies, the avidity test further assesses the binding strength of these antibodies to distinguish between recent and past infections
 

Q. What do low avidity results indicate?
Low avidity results suggest a recent CMV infection, which could be of concern during early pregnancy due to the risk of transmitting the virus to the fetus
 

Q. Can the CMV Avidity IgG Test be used in immunocompromised patients?
Yes, it helps in determining whether an immunocompromised patient has a recent or reactivated CMV infection, which is critical for managing their care
 

Q. Is any preparation required before taking the CMV Avidity IgG Test?
No special preparation is required, but you should inform your healthcare provider about any medications or conditions that might affect the test results
 

Q. How soon will I get the results of the CMV Avidity IgG Test?
Results are typically available within a few days, depending on the laboratory processing time