CD19+ B-cells in autoantibody-negative limbic encephalitis.

Abstract Purpose Flow cytometry helps to elucidate the cellular immune repertoire's mechanisms in patients with temporal lobe epilepsy (TLE) due to limbic encephalitis (LE) subcategories and carries potential significance for subtype-specific treatment. Methods We enrolled 62 patients with TLE due to LE associated with no autoantibodies (n = 40), neural autoantibodies (n = 22), as well as autoantibodies against intracellular antigens (n = 15/22). All patients underwent neuropsychological testing, brain magnetic resonance imaging (MRI), electroencephalography (EEG) recordings, and peripheral blood (PB) and cerebrospinal fluid (CSF) investigations including flow cytometry. Results CD19 + B-cells were increased in the PB and CSF of patients with antibody-negative LE compared with those associated with antibodies against intracellular antigens (Kruskal–Wallis one way analysis of variance (ANOVA) on ranks with Dunn's test, p  Conclusions The increase of CD19 + B-cells in the CSF and frequent signs of dysfunctional blood–brain barrier in patients with antibody-negative rather than intracellular antibody-positive LE suggest that CD19 + B-cells play a role in antibody-negative encephalitis although their pathogenic role in the central nervous system (CNS) immunity because of missing correlations between immune cells and clinical and paraclinical parameters remains unknown. Further studies are required to evaluate the usefulness of these B-cells as a biomarker for the stratification of treatment strategies.