HERPES SIMPLEX VIRUS (HSV) 1+2 IgG, CSF
Herpes simplex meningoencephalitis is a severe illness that causes inflammation of the brain and its surrounding membranes. Despite available antiviral treatments, the disease is fatal, which makes prompt diagnosis and treatment crucial.
Most cases of herpes encephalitis in adults are caused by the HSV-1 virus, with less than 10% attributed to HSV-2. In newborns, meningoencephalitis may be caused by either HSV-1 or HSV-2.
If you experience neurological symptoms suggestive of a herpes infection, your doctor may recommend a Herpes Simplex Virus 1+2 IgG test in cerebrospinal fluid (CSF). This test detects the presence of IgG antibodies your body produces in response to the virus. While a "fourfold increase" in IgG levels typically indicates a positive result, it does not necessarily confirm an active infection, and further testing may be needed.
What is the HSV 1+2 IgG Test Used For?
The HSV 1+ 2 IgG Antibody test is used:
To determine if a patient has previously been exposed to HSV in the central nervous system (CNS)
To differentiate HSV type 1 infection from HSV type 2.
To check if expectant mother had prior infection with HSV
Symptoms of HSV Encephalitis
The possible symptoms of HSV-related encephalitis include:
Headache
Fever
Stiff neck
Seizure
Loss of memory
Problems with speech or hearing
Frequent loss of consciousness
Change in mood or behaviour
Loss of bladder and bowel control
Preparation for Test
Before taking an HSV1+2 IgG antibody test, let your doctor know your complete medical history, including over-the-counter medicines or dietary supplements you are taking, so they can correlate your clinical and laboratory findings and provide a suitable treatment plan.
Interpretation of Test Results
The interpretation of the HSV1+2 IgG antibody results varies depending on the type of HSV detected in the sample. They are as follows:
Positive result(Abnormal)
This report suggests the presence of IgG antibodies against HSV 1 and HSV 2 in CSF, which may indicate current or past exposure to herpes infection.
Negative result(Normal)
This report means no significant levels of IgG antibodies were detected in the CSF sample, although the possibility of HSV infection cannot be excluded. Retesting is, therefore, recommended after 10-14 days of initial illness.
Equivocal
The results are questionable. Retesting may be helpful after 10-14 days.
FAQs
What does it mean if you test positive for HSV 1+2 IgG in CSF but not IgM?
Such a report usually means that you were exposed to HSV for more than two months.
What precautions should I take when interpreting the HSV 1+2 IgG Antibody test results in CSF?
When interpreting the results of the HSV 1+2 IgG antibody test in cerebrospinal fluid (CSF), consider these factors:
- The presence of HSV IgG antibodies indicates a previous exposure to the virus, not necessarily an active infection.
- Early testing (within a few days of symptoms) may lead to false-negative results.
- Results vary depending on the type of HSV and the patient's immune status. In immunocompromised individuals, the presence of IgG antibodies may indicate reactivation of an old HSV infection, requiring additional testing to confirm the diagnosis.
- False-positive results may also occur in patients infected with other herpesviruses( such as Epstein-Barr virus (EBV), varicella-zoster virus (VZV), or cytomegalovirus (CMV)).
What risks are associated with the Herpes Simplex Virus 1 + 2 IgG Antibody test?
The Herpes Simplex Virus 1 + 2 IgG antibody test carries minimal risk. However, there is a slight possibility of experiencing pain or bruising at the needle insertion site.
Is it possible for the HSV IgG test results to change over time?
It's very uncommon for HSV IgG test results to change dramatically once they become positive. But there are rare circumstances where IgG levels might fluctuate:
- During the early stage of HSV infection, when IgG levels are still building up in the body, the test may miss them and give negative results.
- Due to illness or medication, people with weakened immune systems may experience a temporary dip in IgG levels. However, this does not rule out the infection.
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