Effects of multiple sclerosis and other inflammatory CNS disorders on tick-borne encephalitis serology

The goal of the present study was to investigate whether a direct associati on exists between false-positive recognition of IgG antibodies and inflamma tory changes in the central nervous system (CNS) and whether inflammatory d iseases of the CNS affect the specificity of the enzyme-linked immunosorben t assay (ELISA) of tick-borne encephalitis (TBE) virus. A group of patients (1,815), treated in the Department of Neurology, University Hospital of th e Saarland, Homburg/Saar, Germany, were tested for TBE IgG antibodies by EL ISA. Several subgroups of patients with and without inflammatory changes in the CSF as well as patients with and without confirmed multiple sclerosis (MS) were investigated. Overall, 4.5% of all the 1,815 patients and 4.8% of the patients with inflammatory changes in the CSF but without MS had TEE I gG antibodies. In the subgroup with inflammatory changes in the CSF and MS, 4.4% of the patients were TEE IgG-positive. In the subgroup without inflam matory changes in the CSF, 3.8% of the patients without MS were TEE IgG-pos itive and 4.9% of the patients with MS were TEE IgG-positive. The rate of T EE IgG positivity was not significantly different in the subgroups with and without inflammatory changes in the CSF (P = 0.45). The comparison of the subgroups with and without MS showed no significant difference in the TEE I ge titer (P = 0.83) as well. This indicates that the specificity of the ELI SA was affected neither by inflammatory changes in the CSF nor by MS.