What is the purpose of this test?
Order this Human Herpesvirus 6 (HHV-6) Antibodies Blood Test, IgG detects HHV-6 IgG antibodies in the blood. HHV-6 is a herpesvirus that belongs to the family and has two subtypes: HHV-6A and HHV-6B—approximately 90% of children in the US contract HHV-6B infections by the age of 2. The impact of HHV-6A on human health is still uncertain. HHV-6 can become dormant after the initial infection and reactivate later in life, like other human herpes viruses. Other members of the herpes family include EBV, CMV, VZV, HHV-7, HSV-1, and HSV-2.
HHV-6 has been associated with chronic fatigue (CFS) and fever in adults, similar to mononucleosis. An elevated IgM HHV-6 is helpful during the acute episode, and increased IgG HHV-6 between acute and convalescent serum samples indicates a recent HHV-6 infection. IgG antibodies typically develop a few weeks after infection and may last indefinitely. IgM only appears during an active infection or 2-3 months after an active infection. The absence of an IgM antibody does not mean you do not have an active infection. Chronic infections in various tissues can persist with no evidence of IgM.
For transplant patients, HHV-6 can become active and cause symptoms, leading to bone marrow suppression after transplantation, resulting in anemia, decreased immunity, and bleeding due to low white blood cell levels and platelets, leading to fatigue. Research has established this link.
When should I order a Human Herpesvirus 6 (HHV-6) Antibodies Blood Test, IgG?
Individuals may order this test if they have experienced symptoms related to HHV-6 infection. Common symptoms HHV-6 causes include:
- Fever
- Runny nose
- Rash
- Diarrhea
HHV-6 can also cause symptoms known as roseola infantum, commonly referred to as exanthem subitum or just roseola. This condition affects 20-30% of HHV-6 infections and typically occurs in children between 6 months and two years old. Roseola is characterized by a high fever lasting 3-5 days and a rash that starts on the body and spreads.
In rare cases, HHV-6 infections can result in severe inflammation of the lining around the brain (meningitis) and the brain itself (encephalitis). These conditions can be life-threatening and require hospitalization and treatment. Individuals with weakened immune systems, cancer, and transplant recipients are more at risk for these severe infections.