Introduction:
Chemokine ligand 13 (CXCL13) has been reported to be a valuable diagnostic biomarker in Lyme neuroborreliosis (LNB). However, its utility in the diagnostics of viral and autoimmune (AE) encephalitis still remains unclear.

Material and methods:
We have measured CXCL13 concentrations in cerebrospinal fluid (CSF) samples collected from 21 patients with viral encephalitis (17 cases of herpes simplex viral (HSV) and four of enteroviral (EV) encephalitis), six patients with AE (five subjects with antibodies anti-NMDAR and one with anti-GABA) and compared them to those found in patients with LNB (seven subjects), multiple sclerosis (eight cases) and ten controls comprised of subjects without neuroinflammation.

Results:
Patients with neuroinflammation had a mean level of CXCL13-CSF of 105 pg/ml compared to a value of 29 pg/ml for controls. The highest mean level of CXCL13 in CSF was detected in LNB patients (233 pg/ml) whereas the lowest was in controls (29pg/ml). A significant upregulation of CXCL13-CSF levels in LNB patients was determined when compared to viral encephalitis, MS and controls. A positive correlation between the increased levels of chemokine and cell count in CSF was found in all patients (r=0.6496; p<0.0001), as well as, in LNB group when tested alone (r=0.8428; p=0.0173). Positive correlation with CSF protein levels was confirmed in all patients (r=0.7216; p<0.0001), and separately in LNB (r=0.8573; p=0.0137) and AE patients (r=0.8885; p=0.0180).

Conclusions:
The utility of CXCL13 measurements in CSF for LNB diagnosis was confirmed. No specific patterns in CXCL13-CSF levels were associated with viral and autoimmune encephalitis.