Serum antiganglioside antibodies in patients with autoimmune limbic encephalitis.

BACKGROUND: Ganglioside antibodies are identified not only in patients with inflammatory neuropathies but also several central nervous system disorders and paraneoplastic neuropathies. Our aim was to investigate whether ganglioside antibodies are found in autoimmune encephalitis patients and may function as a diagnostic and prognostic biomarker. METHODS: Sera and cerebrospinal fluid (CSF) samples of 33 patients fulfilling the criteria for probable autoimmune encephalitis were collected within the first week of clinical manifestation. None of the patients had evident symptoms and findings of peripheral polyneuropathy. Well-characterized antineuronal and paraneoplastic antibodies were investigated in sera and CSF and antiganglioside (antiGM1, GM2, GM3, GD1a, GD1b, GT1b, and GQ1b) IgG and IgM antibodies were measured in sera using commercial immunoblots. RESULTS: Twenty-eight of 33 autoimmune encephalitis patients displayed antibodies against neuronal surface or onco-neural antigens with N-methyl-D-aspartate receptor (NMDAR), glutamic acid decarboxylase (GAD) and Hu antibodies being the most prevalent. While no antiganglioside IgG antibodies were found, 4 patients (2 anti-NMDAR+, 1 anti-GAD+ and 1 antibody negative) with autoimmune limbic encephalitis displayed anti-GM1, anti-GM2, anti-GM3 or anti-GQ1b IgM antibodies. There was no apparent association between antiganglioside positivity and clinical and demographic features. DISCUSSION: Serum ganglioside IgM antibodies may infrequently emerge during the clinical course of autoimmune limbic encephalitis without evident polyneuropathy. Absence of the IgG response suggests that these antibodies might have developed as a hyperacute immune response to neuro-axonal destruction. Nevertheless, potential impact of ganglioside antibodies on axonal degeneration and neuronal loss in limbic encephalitis pends to be further investigated.

The Relationship of Serum S100B Levels with Infarction Size and Clinical Outcome in Acute Ischemic Stroke Patients.

INTRODUCTION: S100B protein, which helps nerve development and differentiation, is produced by astrocytes and can be detected in peripheral circulation after brain damage. In this study, we aimed to investigate the relationship between the serum S100B protein level and the infarction volume and clinical outcome and also the early prognostic role of serum S100B protein in patients with ischemic stroke. METHOD: Fifty patients admitted in the first 24-hour period of acute ischemic stroke were evaluated prospectively, and the findings were compared to those of the controls (n=26). S100B levels of the patients and neurological findings on days 1, 3, and 5 and their functional outcomes on the discharge day and at the first month were recorded by the same examiner. RESULTS: S100B levels were not affected by sex, age, or concomitant systemic diseases. The maximum levels of S100B were recorded on the 3rd day, and there was a correlation between infarct size and S100B levels. No correlation between the severity of stroke and S100B level was found. There was a poor correlation between the functional outcomes of the patients at the 1st month and S100B levels and on the 3rd day. CONCLUSION: The detection of high S100B levels in peripheral circulation after acute ischemic stroke and the correlations of S100B levels with infarct size (good) and disability (poor) imply that S100B protein may be used as a peripheral marker in acute ischemic stroke patients.