The Cerebrospinal Fluid Interleukin-6/Interleukin-10 Ratio Differentiates Pediatric Tick-borne Infections

Background: Borrelia burgdorferi and tick-borne encephalitis (TBE) virus are 2 types of tick-borne pathogens that can cause central nervous system infection. Routine diagnostics have so far included analysis of cerebrospinal fluid (CSF) cell numbers, CSF serology for Borrelia burgdorferi and serum serology for TBE virus. However, early diagnosis may be difficult based on antibody detection which takes time to analyze, and with the possibility of false negative results, thus delaying treatment. Cytokine analyses are becoming increasingly available in clinical routine care and may offer important information. Methods: Fifteen cytokines and chemokines were measured in the CSF from the diagnostic lumbar puncture of 37 children with TBE, 34 children with neuroborreliosis and 19 children without evidence of central nervous system infection, using Luminex technology. Results: Significantly higher levels of proinflammatory interleukin-6 were detected in the samples from TBE-infected children, when compared with neuroborreliosis or controls. In comparison, children with neuroborreliosis had significantly higher levels of interleukin-7, interleukin-8, interleukin-10, and interleukin-13 when compared with TBE infected or controls. Furthermore, the ratio between interleukin-6 and interleukin-10 was significantly different between the 2 types of tick-borne infections. Conclusions: The interleukin-6/interleukin-10 ratio can be used as a rapid diagnostic cue upon suspected tick-borne infection, enabling fast and correct treatment. Also, in serology-negative results, such information may strengthen a clinical suspicion.