Cerebrospinal fluid CXCL13 in non-borrelial central nervous system infections: contribution of CXCL13 to the differential diagnosis

BackgroundThe chemokine CXCL13 in cerebrospinal fluid (CSF) is used as a diagnostic marker of Lyme neuroborreliosis (LNB). However, the elevated levels in other non-borrelial CNS infections and the lack of a clearly defined cut-off value are limitations of the test.MethodsIn our prospective study, we evaluated CSF CXCL13 levels in patients with LNB (47 patients), tick-borne encephalitis (TBE; 46 patients), enteroviral CNS infections (EV; 45 patients), herpetic CNS infections (HV; 23 patients), neurosyphilis (NS; 11 patients) and controls (46 patients). The correlation of CXCL13 with CSF mononuclears was determined in all groups.ResultsMedian CXCL13 was significantly higher in LNB group; however, the cut-off value of 162 pg/mL was also exceeded in 22% of TBE patients, 2% EV patients, 44% HV patients and in 55% patients with NS. Sensitivity and specificity were 0.83 and 0.78, respectively, with a Youden index of 0.62. CXCL13 was significantly correlated with CSF mononuclears (p = .0024), but the type of infectious agent had a greater influence on CXCL13 levels.ConclusionsIncreased CXCL13 levels are useful for LNB diagnostics, but other non-purulent CNS infections causes should be considered if intrathecal synthesis of borrelia specific antibodies is not confirmed or clinical manifestations are atypical.

Automated summary

This study evaluated the levels of CXCL13 in the cerebrospinal fluid of patients with different types of CNS infections. It found that the levels of CXCL13 were significantly elevated in patients with Lyme neuroborreliosis. However, elevated levels of CXCL13 were also found in other types of infections, indicating that caution should be taken in diagnosing Lyme neuroborreliosis based solely on CXCL13 levels.