Extensive axonal and neuronal loss is the main cause of severe manifestations and poor outcomes in tick-borne encephalitis (TBE). Phosphorylated neurofilament heavy subunit (pNF-H) is an essential component of axons, and its detection in cerebrospinal fluid (CSF) or serum can indicate the degree of neuroaxonal damage. We examined the use of pNF-H as a biomarker of neuroaxonal injury in TBE. In 89 patients with acute TBE, we measured CSF levels of pNF-H and 3 other markers of brain injury (glial fibrillary acidic protein, S100B and ubiquitin C-terminal hydrolase L1) and compared the results to those for patients with meningitis of other aetiology and controls. Serum pNF-H levels were measured in 80 patients and compared with findings for 90 healthy blood donors. TBE patients had significantly (P<0.001) higher CSF pNF-H levels than controls as early as hospital admission. Serum pNF-H concentrations were significantly higher in samples from TBE patients collected at hospital discharge (P<0.0001) than in controls. TBE patients with the highest peak values of serum pNF-H, exceeding 10 000 pg ml-1, had a very severe disease course, with coma or tetraplegia. Patients requiring intensive care had significantly higher serum pNF-H levels than other TBE patients (P<0.01). Elevated serum pNF-H values were also observed in patients with incomplete recovery (P<0.05). Peak serum pNF-H levels correlated positively with the duration of hospitalization (P=0.005). Measurement of pNF-H levels in TBE patients might be useful for assessing disease severity and determining prognosis.

Department of Children's Infectious Disease Faculty of Medicine and University Hospital Masaryk University CZ 61300 Brno Czechia

Department of Experimental Biology Faculty of Science Masaryk University CZ 62500 Brno Czechia

Department of Infectious Diseases and Preventive Medicine Veterinary Research Institute CZ 62100 Brno Czechia

Department of Infectious Diseases Hospital Ceske Budejovice CZ 37001 Ceske Budejovice Czechia

Department of Infectious Diseases University Hospital Brno and Faculty of Medicine Masaryk University CZ 62500 Brno Czechia

Faculty of Science University of South Bohemia CZ 37005 Ceske Budejovice Czechia

Institute of Parasitology Biology Centre of the Czech Academy of Sciences CZ 37005 Ceske Budejovice Czechia

Royal Liverpool University Hospital Prescot St Liverpool L7 8XP UK

References provided by Crossref.org

Serum matrix metalloproteinase-9 (MMP-9) as a biomarker in paediatric and adult tick-borne encephalitis patients