Cytomegalovirus Antibody (IgG)

The Cytomegalovirus Antibody (IgG) test contains 1 test with 1 biomarker.

Brief Description: The Cytomegalovirus (CMV) IgG Antibody test is a serological assay designed to detect the presence of IgG antibodies specific to the cytomegalovirus in a patient's blood. CMV is a common virus belonging to the herpesvirus family, and this test aids in assessing a patient's immune response to previous CMV exposure or infection.

Also Known As: CMV Test, CMV Antibodies Test, CMV IgG Test, Cytomegalovirus Test, Cytomegalovirus IgG Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a Cytomegalovirus IgG Antibody test ordered?

When a younger person, a pregnant woman, or an immune-compromised individual exhibits flu- or mono-like signs and symptoms, CMV tests, as well as tests for influenza, mononucleosis, and EBV, may be requested.

When a health care provider is assessing the effectiveness of antiviral therapy, one or more CMV tests may be ordered at regular intervals.

CMV antibody testing may be requested as a screening test to discover if a person has been exposed to CMV in the past when they are a candidate for an organ or marrow transplant.

What does a Cytomegalovirus IgG Antibody blood test check for?

Cytomegalovirus is a widespread virus that is found all over the world but only rarely causes symptoms. CMV infection affects between 50 and 85 percent of individuals in the United States. The majority of persons get infected as children or young adults and have no noticeable symptoms or health problems.

CMV testing entails measuring CMV antibodies, immunological proteins produced in response to CMV infection, or detecting the virus itself. Culturing CMV or detecting the virus's genetic material in a fluid or tissue sample might be used to identify the virus during an active infection.

During an active infection, CMV can be discovered in a variety of body fluids, including saliva, urine, blood, breast milk, sperm, vaginal secretions, and cerebrospinal fluid. Close personal touch or interaction with infected materials, like as diapers or toys, makes it easy to spread to others. CMV, like other members of the herpes family, becomes dormant or latent after the initial "primary" infection has cured. Unless a person's immune system is considerably impaired, cytomegalovirus can live in them for the rest of their lives without creating any symptoms. The virus may reactivate if this occurs.

In three scenarios, CMV can cause serious health problems:

• Primary CMV infection in young adults can induce a flu-like or mononucleosis-like disease. Extreme weariness, fever, chills, body pains, and/or headaches are common symptoms of this ailment, which normally goes away in a few weeks.
• Primary CMV infection in babies can result in major physical and developmental issues. This happens when a pregnant woman becomes infected for the first time and then distributes the infection to her unborn child through the placenta. Most infected neonates appear healthy at birth, but within a few months, they may develop hearing or vision abnormalities, pneumonia, convulsions, and/or impaired mental development. Some babies are stillborn, while others show signs including jaundice, anemia, an enlarged spleen or liver, and a small head when they are born.
• CMV can cause significant disease and death in people who have weaker immune systems. This includes those living with HIV/AIDS, people who have undergone organ or bone marrow transplants, and people who are receiving cancer chemotherapy. People with weakened immune systems who become infected for the first time may have the most severe symptoms, and their CMV infection may be active for a long time. Those who have previously been exposed to CMV may experience reactivation of their infection. Their eyes, digestive tract, lungs, and brain could all be affected. Spleen and liver problems are also possible, and people who have had organ or bone marrow transplants may have some rejection. Active CMV also weakens the immune system, making it easier for secondary infections like fungal infections to develop.

Lab tests often ordered with a Cytomegalovirus IgG Antibody test:

When a CMV IgG test is ordered, it's often part of a broader evaluation for infection, immune status, or in specific contexts such as pregnancy. Here are some tests commonly ordered alongside it:

1. CMV IgM Antibody Test:

   • Purpose: To detect a recent or current CMV infection.
   • Why Is It Ordered: IgM antibodies are typically the first to respond to a viral infection. The presence of CMV IgM antibodies suggests a recent or acute CMV infection.

2. Complete Blood Count (CBC) with Differential:

   • Purpose: To evaluate overall blood health, including white and red blood cells and platelets.
   • Why Is It Ordered: To check for signs of infection or for blood disorders that can sometimes be associated with CMV infection.

3. Liver Function Test:

   • Purpose: To assess liver health.
   • Why Is It Ordered: CMV can affect the liver, leading to elevated liver enzymes.

4. Rubella, Toxoplasma, and Herpes Simplex Virus Serologies:

   • Purpose: To screen for other infections that can cause symptoms similar to CMV or are important in pregnancy (part of TORCH infections).
   • Why Is It Ordered: To rule out or identify other infections, especially in pregnant women or newborns.

These tests, when ordered alongside a CMV IgG Antibody test, provide a comprehensive evaluation of CMV infection status and help to assess the risk of CMV-related complications, especially in immunocompromised patients and during pregnancy. They are crucial for diagnosing and managing CMV infection and for monitoring the health of affected individuals. The specific combination of tests will depend on the individual’s symptoms, clinical presentation, and risk factors.

Conditions where a Cytomegalovirus IgG Antibody test is recommended:

The CMV IgG Antibody test is essential in several clinical contexts, including:

1. Pregnancy: The test helps identify pregnant women who are immune to CMV and thus less likely to transmit the virus to the fetus.

2. Immunocompromised Individuals: Patients with weakened immune systems, such as transplant recipients or those with HIV, are at greater risk of CMV-related complications. The test aids in monitoring their immune response.

3. Symptomatic Individuals: Individuals presenting with symptoms suggestive of CMV infection, such as fever, fatigue, and swollen glands, might undergo the test to confirm exposure.

How does my health care provider use a Cytomegalovirus Antibody IgG test?

Cytomegalovirus testing is performed to see if someone has an active CMV infection based on their signs and symptoms. It's sometimes ordered to see if someone has ever been infected with CMV before.

CMV is a widespread virus that affects a large percentage of the population but rarely produces symptoms or serious health concerns. In neonates and persons with weaker immune systems, such as transplant recipients, cancer patients, people taking immunosuppressive medicines, and people living with HIV, primary CMV infection can cause serious sickness and consequences.

Antibody testing on blood samples can be used to detect if someone has been exposed recently or previously.

The body produces IgG antibodies several weeks after the original CMV infection, which defend against secondary infections. IgG levels rise during active infection, then level off as the CMV infection fades and the virus becomes dormant. After being exposed to CMV, a person's blood will contain quantifiable amounts of CMV IgG antibodies for the rest of their lives. Along with IgM testing, CMV IgG antibody testing can be used to establish the existence of a current or previous CMV infection.

CMV antibody testing can be used to determine immunity to primary CMV infections in people who are awaiting organ or bone marrow transplantation, as well as in HIV/AIDS patients. CMV infection is common and causes minimal difficulties in those with healthy immune systems, hence general population screening is uncommon.

What do my CMV IgG test results mean?

When interpreting the findings of CMV testing, caution is advised. The results are compared to clinical data, such as signs and symptoms, by a health professional. It's not always easy to tell the difference between a latent, active, or reactivated CMV infection. This is attributable to a number of factors, including:

A healthy individual who has been infected with CMV will carry the virus for the rest of their lives. CMV can reactivate on a regular basis, frequently in a subclinical manner, shedding small amounts of virus into body fluids but causing no symptoms.

Even if the individual has an active case of CMV, an immune-compromised person may not have a significant antibody response to the infection; the person's IgG levels may be lower than predicted.

It's possible that the virus isn't present in large enough numbers in the fluid or tissue being analyzed to be detected.

A symptomatic person with positive CMV IgG and IgM has most likely been exposed to CMV for the first time or has had a previous CMV infection reactivated. IgG levels can be measured again 2 or 3 weeks later to confirm this. A high IgG level is less essential than an increasing level. If the IgG level in the first and second samples differs by fourfold, the person is infected with CMV.

A positive CMV IgM and negative IgG indicates that the person was infected recently.

In someone who is symptomatic, a negative IgG and/or IgM or low levels of antibodies may indicate that the person has a problem other than CMV or that their immune system is not responding correctly.

Most Common Questions About the Cytomegalovirus IgG Antibody test:

Purpose and Clinical Significance

What is the primary objective of the Cytomegalovirus IgG Antibody test?

The Cytomegalovirus IgG Antibody test is designed to detect the presence of IgG antibodies against the cytomegalovirus (CMV) in the blood. These antibodies indicate a past or recent infection with CMV.

Why is the Cytomegalovirus IgG Antibody test ordered?

The test is often ordered to determine if an individual has been previously exposed to CMV, especially in scenarios where the person might be at risk for reactivation of the virus, such as organ transplant recipients or individuals with compromised immune systems.

Interpretation of Results

What does a positive result in the Cytomegalovirus IgG Antibody test signify?

A positive result indicates that the individual has IgG antibodies against CMV, suggesting a past or recent CMV infection. This typically means the person has been exposed to CMV at some point in their life and has developed immunity against it.

If the Cytomegalovirus IgG Antibody test is negative, can one still have CMV?

A negative result suggests that the individual doesn't have detectable IgG antibodies against CMV and thus likely hasn't had a CMV infection in the past. However, it doesn't rule out a current active infection, especially if the exposure was recent. In cases of suspected recent infection, an IgM antibody test for CMV might be ordered.

Disease and Complications

How is the Cytomegalovirus IgG Antibody test related to mononucleosis-like illnesses?

CMV can cause a mononucleosis-like syndrome in previously healthy individuals. This condition can have symptoms similar to those caused by the Epstein-Barr virus, the primary cause of mononucleosis. The Cytomegalovirus IgG Antibody test can help differentiate between the two if a mononucleosis test is negative or if CMV is suspected.

Who is at risk for severe complications from CMV?

While CMV infections are usually mild or even asymptomatic in healthy individuals, they can be severe in people with weakened immune systems, such as organ transplant recipients, HIV/AIDS patients, and individuals on immunosuppressive drugs. Newborns infected during pregnancy can also face serious complications, including hearing loss, vision problems, and developmental disorders.

Relation with Other Tests

Why might one need both IgG and IgM tests for CMV?

The IgM antibody typically indicates a recent CMV infection, while the IgG antibody points to a past infection. If a person has clinical signs suggesting CMV but tests negative for CMV IgG, an IgM test can be ordered to check for recent exposure. Conversely, if someone tests positive for CMV IgM, the IgG test can help determine if it's a new infection or a reactivation of a past one.

Can the Cytomegalovirus IgG Antibody test replace the PCR test for CMV detection?

No, while the Cytomegalovirus IgG Antibody test detects antibodies and indicates exposure, the PCR test detects the actual presence of the virus's genetic material in blood or other body fluids. PCR is particularly useful in diagnosing active CMV infections, especially in immunocompromised patients or in newborns suspected of congenital CMV infection.

Remember, while the Cytomegalovirus IgG Antibody test provides insights into past or recent CMV exposure, it is crucial to consider the broader clinical context, including symptoms, other test results, and patient history, for a comprehensive assessment.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.