Cytomegalovirus (CMV) IgG Antibody, Serum/Plasma

Why This Test Is Done

Doctors may order this test to determine if you’ve had exposure to CMV in the past. It can also help evaluate immune function in people with weakened immune systems, such as those with HIV/AIDS or undergoing certain treatments like chemotherapy. Sometimes, it’s used to monitor long-term immunity in transplant recipients or individuals with chronic conditions like lupus or rheumatoid arthritis.

What to Expect Before the Test

You’ll typically have a small needle inserted into a vein in your arm to draw blood. The process takes about 5 minutes. No special preparation is needed, but let your doctor or lab know about any medications you’re taking or recent illnesses.

What the Results Mean

A positive result means you have CMV IgG antibodies, suggesting past infection. A negative result indicates no detectable antibodies, meaning either you’ve never been exposed or the test was taken too soon after exposure. Interpretation depends on clinical context, such as your medical history or symptoms.

Common Reasons for Testing

This test is often used in high-risk groups, such as pregnant women (to check for congenital CMV risk), transplant patients, or those with immune deficiencies. It may also be part of routine monitoring for chronic diseases or to assess immune health.