Diagnostic performance of cerebrospinal fluid chemokine CXCL13 and antibodies to the C6-peptide in Lyme neuroborreliosis.

Objective: The aim of this study was to evaluate the chemokine CXCL13 and C6 antibodies separately and in combination in paired serum/cerebrospinal fluid (CSF) samples in the laboratory diagnosis of Lyme neuroborreliosis (LNB).

Methods: A large retrospective material with paired serum/CSF samples from 261 patients with clinically suspected LNB was investigated. Patients were divided into three main diagnostic groups based on original results of CSF pleocytosis and intrathecal anti-borrelia antibodies (purified flagellum). Levels of CXCL13, albumin, total IgM and IgG in paired samples and C6 antibodies in CSF were compared across diagnostic groups.

Results: A sensitivity of 99% and a specificity of 96% were achieved for CSF-Serum CXCL13 ratio. CSF-C6 antibodies performed with a sensitivity of 99% and a specificity of 88.0%. A combination of CSF-Serum CXCL13 ratio and CSF-C6 antibodies, evaluated in parallel, revealed a sensitivity of 99% and specificity of 98%.

Conclusions: This study confirms CSF-CXCL13 as a reliable marker of LNB and suggests improved diagnostic performance especially in children with possible LNB.