Photo Credit: nechaev

The following is a summary of “Kinetics of tick-borne encephalitis virus IgM antibody responses in serum and cerebrospinal fluid,” published in the March 2025 issue of Infectious Diseases by Morgardt et al. 

The detection of IgM and IgG antibodies in serum and cerebrospinal fluid (CSF) is essential for diagnosing tick-borne encephalitis (TBE), but the kinetics of TBE virus (TBEV) IgM in CSF remains largely unknown.  

Researchers conducted a retrospective study to assess the duration and strength of the IgM antibody response in serum and CSF after the diagnosed of clinical TBE and examined its correlation with disease severity and residual symptoms.  

They analyzed 69 paired serum and CSF samples from 31 individuals with TBE using the ReaScan TBE IgM test. Samples were collected during the emergency phase and at multiple follow-up visits over a period of up to 6 years. Recovery was assessed using the Glasgow Outcome Scale (GOS), which measures disability and social participation.  

The results showed that at initial sampling, 97% (30/31) tested positive for TBEV IgM in serum and 90% (28/31) in CSF. The IgM antibodies persisted in both fluids for up to 1 year. No correlation was found between IgM levels and disease severity. However, individuals with better recovery at 3 months had significantly higher IgM levels in serum and CSF than those with severe disability.  

Investigators concluded that TBEV IgM antibody detection allowed for both early and late-stage diagnosis, and a stronger IgM response correlated with improved recovery after 3 months. 

Source: tandfonline.com/doi/full/10.1080/23744235.2025.2473496