Veje et al.
Serum and cerebrospinal fluid brain damage markers neurofilament light and glial fibrillary acidic protein correlate with tick-borne encephalitis disease severity—a multicentre study on Lithuanian and Swedish patients
Eur J Neurol. 2023;30(10):3182-3189. doi:10.1111/ene.15978

TBE virus can infect various parts of the central nervous system (CNS), and the damage is caused by direct viral infection or by inflammation. From a prognostic perspective, a variety of brain damage markers have been described in CNS disorders, among which are the neurofilament light (NfL), the glial fibrillary acidic protein (GFAP) and the glycoprotein YKL-40.

In a study comprising a total of 115 TBE patients from Lithuania and Sweden, various markers detected in cerebrospinal fluid (CSF) and serum were analyzed for prognostic value.

Elevated serum and CSF concentrations of both NfL and GFAP were found in TBE patients indicating neuronal cell damage and astroglial activation, and the concentrations correlated with disease severity. Encephalitis with its inflammatory involvement of brain parenchyma, gave rise to higher NfL and GFAP levels, which were found in patients with moderate and severe disease. NfL, GFAP, YKL-40 and S100B concentrations correlated with age, whereas neurogranin and tau levels did not. In this study, CSF YKL-40 levels correlated with a more severe disease. Results in this study indicated that neuronal cell damage and astroglial activation in TBE, and the concentrations of NfL and GFAP in serum and CSF and YKL-40 correlate with disease severity in the acute phase.

While to date, no prognostic biomarkers for TBE exist, the serum markers NfL and GFAP might prove valuable for estimation of brain damage.

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