What does positive cytomegalovirus IgG mean?
A positive test for CMV IgG indicates that a person was infected with CMV at some time during their life but does not indicate when a person was infected. This applies for persons ≥12 months of age when maternal antibodies are no longer present.
What happens if you test positive for CMV?
The majority of children born who experience a CMV infection before birth are healthy and normal. However, 10 to 15% may have complications such as hearing loss, neurological abnormalities, or decreased motor skills. Infants who are infected with CMV after they are born rarely experience any long-term complications.
What happens if cytomegalovirus IgG is high?
Also, if your IgM and IgG levels are high, it may mean you have CMV. Your healthcare provider will likely give you the test again in 2 weeks to confirm the infection. If your IgG levels rise between the first and second test, that may mean you have an active infection.
How is CMV IgG positive treated?
The type of treatment depends on the signs and symptoms and their severity. Antiviral medications are the most common type of treatment. They can slow reproduction of the virus, but can’t eliminate it. Researchers are studying new medications and vaccines to treat and prevent CMV .
How is CMV virus treated?
The drug of choice for treatment of CMV disease is intravenous ganciclovir, although valganciclovir may be used for nonsevere CMV treatment in selected cases. Ganciclovir is a nucleoside analogue that inhibits DNA synthesis in the same manner as acyclovir.
What diseases does CMV cause?
Occasionally, CMV can cause mononucleosis or hepatitis (liver problem). People with weakened immune systems who get CMV can have more serious symptoms affecting the eyes, lungs, liver, esophagus, stomach, and intestines. Babies born with CMV can have brain, liver, spleen, lung, and growth problems.
How is the presence of CMV IgM used in the diagnosis?
The presence of CMV IgM cannot be used by itself to diagnose primary CMV infection because IgM can also be present during secondary CMV infection. IgM positive results in combination with low IgG avidity results are considered reliable evidence for primary infection, with limitations of avidity testing described below.
What is the significance of avidity assays in the workup of CMV?
IgG antibodies produced following primary CMV infection have low avidity (low binding strength). Two to four months following infection, IgG antibodies mature to high-avidity (high binding strength). Therefore, avidity assays can be used to assess low avidity (which indicates recent infection) versus high avidity (past infection).
What is the significance of IgG avidity testing?
Interpretation of Laboratory Tests. IgG avidity testing may provide useful information regarding timing of infection. IgG antibodies produced following primary CMV infection have low avidity (low binding strength). Two to four months following infection, IgG antibodies mature to high-avidity (high binding strength).
What is the significance of Positive CMV-IgG antibody in neonates?
Positive results on CMV-IgG antibody in neonates should be interpreted with caution, since maternal IgG is transferred passively from mother to baby before birth. IgM assays are generally more useful indicators of infection in children below the age of 6 months.