Anti-TBE Intrathecal Synthesis as a Prediction Marker in TBE Patients

Abstract

Tick-borne encephalitis (TBE) is an emerging vector-borne disease in Europe caused by tick-borne encephalitis virus (TBEV), which belongs to Flaviviridae. Although most of the patients quickly recover from TBE, some require further neurological and psychiatric treatment due to persistent symptoms. The aim of the study was to evaluate the usefulness of an antibodies index for predicting the course of the disease and potential persistent sequalae. Sixty-six patients (49 males and 17 females, mean age 45.97 ± 13.69 years) with TBE hospitalized in the Department of Infectious Diseases and Neuroinfections, Medical University of Bialystok, Poland, in years 2016–2019 were included to the study. TBE antibodies titer in serum and CSF samples were measured with an Anti-TBEV ELISA (IgM, IgG) EUROIMMUN test. Patients who developed persistent sequelae after TBE had significantly lower IgG intrathecal index at admission. Additionally, IgG2/IgG1was significantly higher in patients who developed sequelae. IgG intrathecal index might be a useful tool for the prediction of TBE sequelae development.

Results of Tick-Borne Encephalitis Virus (TBEV) Diagnostics in an Endemic Area in Southern Germany, 2007 to 2022

“…This is also comparable to our results, which are based on the first paired CSF and serum samples obtained after admission. Another recent study links a low or delayed intrathecal IgG response to the development of persistent sequelae following TBE but does not report how many patients had a detectable intrathecal IgG response at the different time points in the course of disease [11].…”

“…The CSF/serum quotient for TBEV IgG was determined by dividing the concentration of TBEV IgG in CSF by the TBEV IgG concentration in serum, taking the chosen dilutions into account. If total IgG and albumin concentrations were available for the respective CSF/serum pair, the TBEV IgG antibody index (AI) was then calculated by division of the TBEV IgG quotient by the total IgG quotient or the Q lim derived from the albumin quotient as described by Siemieniako-Werszko et al [11]. An AI > 1.5 was considered indicative of TBEV-specific intrathecal IgG synthesis.…”

Defining the “Correlate(s) of Protection” to tick-borne encephalitis vaccination and infection – key points and outstanding questions

“…Intrathecal synthesis of total IgG, IgM, and also IgA appears to be higher in severe, compared to mild, disease ( 24 , 137 ). On the other hand, a lower IgG intrathecal index at hospital admission is a possible risk factor for developing persistent sequelae ( 142 ), and the intrathecal anti-TBEV IgM response may be associated with significantly quicker resolution of the cellular CSF infiltrate ( 137 ). Thus, the role of intrathecally produced antibodies remains somewhat unclear and would benefit from further investigations.…”