HSV IgG antibody inhibits virus detection in CSF

Area of Science:

• Neurovirology
• Immunology
• Infectious Diseases

Background:

• Traditional diagnosis of herpes encephalitis (HSE) relied on brain biopsy for virus isolation.
• Cerebrospinal fluid (CSF) virus isolation for HSE diagnosis has limited clinical utility due to low recovery rates.

Purpose of the Study:

• To investigate the role of anti-herpes simplex virus (HSV) antibodies in the recovery of HSV from CSF using cell culture.
• To determine if antibodies in CSF inhibit HSV replication in vitro.

Main Methods:

• CSF samples from patients with acute HSV central nervous system (CNS) disease were analyzed for viral neutralization capacity.
• HSV-specific IgG and IgM antibodies were detected, and IgG was removed using magnetic beads to assess its inhibitory effect.
• CSF from asymptomatic individuals was used for comparison.

Main Results:

• All analyzed CSF samples demonstrated significant neutralization of both HSV-1 and HSV-2.
• High levels of anti-IgG antibodies were present in all samples, while anti-IgM was absent.
• Removal of IgG abolished the viral inhibitory activity in CSF.
• Neutralizing IgG antibodies were frequently detected in CSF, even in the absence of HSE.

Conclusions:

• Viral-specific IgG is the primary factor inhibiting HSV recovery in CSF cell cultures.
• Inhibitory IgG in CSF of non-HSE patients originates from serum and is commonly present.
• The presence of inhibitory IgG in CSF does not confer protection against the development of HSE.