(INF-P3) CXCL13 in patients with facial palsy caused by varicella zoster virus and Borrelia burgdorferi: A comparative study
The chemokine CXCL13 has emerged as a possible diagnostic marker of Lyme neuroborreliosis (LNB). When measured in cerebrospinal fluid (CSF), CXCL13 has shown to be significantly higher in patients with LNB compared to other central nervous system (CNS) infections. A variety of suggested cut-off levels for CSF CXCL13, ranging from 61 pg/mL to 1224 pg/mL have been proposed. Additionally, there is no accepted reference method for CXCL13. Facial palsy is a common manifestation of LNB, but can also be caused by varicella zoster virus (VZV). A comparison of CXCL13 in these patient groups has not been performed previously.
28 patients with VZV facial palsy, diagnosed by detection of VZV DNA in CSF by PCR, were retrospectively identified. 21 patients with facial palsy caused by LNB were included. The median number of days between debut of facial palsy and CSF sampling was 2 (-9-10) for VZV patients and 4 (1-35) for LNB patients. A control group with 52 patients without CNS infection was included. CXCL13 was measured in stored CSF samples by ELISA, with a detection limit of 7.8 pg/mL.
Median CSF concentrations of CXCL13 for facial palsy caused by LNB were 1808 pg/mL (15-36924), for VZV facial palsy 9 pg/mL (<7.8-437); all control samples but one were below the detection limit. The differences in CXCL13 concentrations between patients with LNB facial palsy and VZV facial palsy were highly significant (p < 0.0001). ROC analysis-derived cut-off level of 34.5 pg/mL yielded a sensitivity of 82.6% and a specificity of 82.1%.
We can confirm significantly higher concentrations of CXCL13 in CSF of patients with LNB compared to patients with VZV. However, the previously proposed cut-off levels for CXCL13 lead to unacceptably low sensitivity in our material. If CSF CXCL13 is to be used in the clinical setting, further studies are needed.