Cerebrospinal fluid biomarkers in patients with varicella-zoster virus CNS infections

Varicella-zoster virus (VZV) is one of our most common viruses causing central nervous system (CNS) infection with sometimes severe neurological complications. Glial fibrillary acidic protein (GFAp), light subunit of neurofilament protein (NFL) and S-100 beta protein are cerebrospinal fluid (CSF) biomarkers that have been used to estimate the severity of brain damage and outcome in various CNS diseases. So far, these biomarkers have not been utilised to investigate glial pathology and neuronal damage in patients with VZV CNS infections. In this prospective study, we measured CSF GFAp, NFL and S-100 beta as markers of brain damage in 24 patients with acute neurological manifestations and VZV DNA detected in CSF by PCR and compared with a control group (n = 14). Concentrations of CSF NFL and GFAp were increased in patients with VZV CNS infection compared with controls (p = 0.002 and p = 0.03) while levels of S-100 beta were reduced. In patients with VZV encephalitis the elevations of CSF NFL and GFAp were more pronounced compared with patients with other VZV CNS syndromes. No correlations between the levels of biomarkers and viral load, neurological sequels or clinical outcome were found in this limited number of patients. These results indicate that VZV induces neuronal damage and astrogliosis with more severe brain damage in patients with VZV encephalitis than in patients with other neurological complications caused by this virus.