Can anti-AQP4 antibody damage the blood-brain barrier?

Interleukin-33 as a Biomarker Affecting Intrathecal Synthesis of Immunoglobulin in Neuromyelitis Optica Spectrum Disorder and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

INTRODUCTION

The purpose of this study was to analyze IL-33 maybe as a biomarker especially with respect to intrathecal immunoglobulin G (IgG) synthesis which was involved in the immune-mediated process in the demyelinating disease of the central nervous system.

METHODS

We aimed to determine the risk association of the serum and CSF levels of IL-33 in aquaporin-4 (AQP4)+neuromyelitis optica spectrum disorder (NMOSD) patients and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) patients compared with the control group. Levels of inflammatory (IL-2, IL-4, IL-6, and IL-10) markers and QAlb, the IgG index, and 24-h IgG synthesis rate were assessed in 28 AQP4+NMOSD patients and 11 MOGAD patients. Disease severity was assessed using the Expanded Disability Status Scale (EDSS).

RESULTS

The level of IL-33 in serum decreased first but then increased gradually in AQP4+NMOSD and MOGAD. The serum level of IL-2, IL-4, and IL-10 increased more significantly and decreased more rapidly after methylprednisolone treatment. The level of IL-33 in CSF increased progressively in AQP4+NMOSD and MOGAD, especially in MOGAD. The QAlb levels were increased significantly in the CSF of MOGAD patients and AQP4+NMOSD patients on the acute stage of the disease. The IgG index and 24-h IgG synthesis rate were also increased significantly in the CSF of two groups similarly.

CONCLUSIONS

Thus, we concluded that IL-33 may induce dysfunction of the blood-brain barrier and lead to intrathecal synthesis of immunoglobulin in the AQP4+NMOSD and MOGAD, especially in MOGAD. It maybe as a biomarker, at least in part, was involved in the demyelinating diseases of the central nervous system.

Pathogenesis of autoimmune demyelination: from multiple sclerosis to neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody-associated disease

Autoimmunity plays a significant role in the pathogenesis of demyelination. Multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein antibody‐associated disease (MOGAD) are now recognised as separate disease entities under the amalgam of human central nervous system demyelinating disorders. While these disorders share inherent similarities, investigations into their distinct clinical presentations and lesion pathologies have aided in differential diagnoses and understanding of disease pathogenesis. An interplay of various genetic and environmental factors contributes to each disease, many of which implicate an autoimmune response. The pivotal role of the adaptive immune system has been highlighted by the diagnostic autoantibodies in NMOSD and MOGAD, and the presence of autoreactive lymphocytes in MS lesions. While a number of autoantigens have been proposed in MS, recent emphasis on the contribution of B cells has shed new light on the well‐established understanding of T cell involvement in pathogenesis. This review aims to synthesise the clinical characteristics and pathological findings, discuss existing and emerging hypotheses regarding the aetiology of demyelination and evaluate recent pathogenicity studies involving T cells, B cells, and autoantibodies and their implications in human demyelination.

Different roles of soluble CD40 ligand in central nervous system damage

Backgroud and purpose: Soluble CD40 ligand (sCD40L) plays an important role in inflammation and autoimmune disorders. There is still a controversy regarding sCD40L in neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS). Herein the aims of this study were to evaluate the levels of sCD40L in patients with NMOSD, MS, and other noninflammatory neurological diseases; to investigate its potential relationship with laboratory parameters, glial fibrillary acidic protein (GFAP), thrombopoietin (TPO) and IL-6; and to address whether serum sCD40L levels in acute attacks of NMOSD patients were decreased after treatment with immunoglobulins, plasma exchange, or methylprednisolone.Materials and methods: We enrolled 13 patients with NMOSD, 9 patients with MS, and 9 patients with other noninflammatory neurological diseases. The levels of sCD40L, IL-6 were measured by cytokine multiplex assay. GFAP levels were measured by ELISA.Results: Both serum and cerebrospinal fluid (CSF) sCD40L levels were increased in NMOSD and MS. No differences were found in serum and CSF sCD40L levels between NMOSD and MS. The CSF sCD40L levels were positively correlated with the CSF cell counts in NMOSD, whereas serum sCD40L levels were positively correlated with the albumin index in MS. Furthermore, the levels of CSF sCD40L were positively correlated with CSF GFAP levels in NMOSD. Serum sCD40L levels were correlated with serum TPO levels in MS. No correlation was found between levels of sCD40L and IL-6 in NMOSD and MS. No statistically meaningful difference between NMOSD patients with or without immunotherapy. Conclusions: Our study suggests that sCD40L can contribute to the destruction of the blood-brain barrier in MS, whereas it may contribute to CNS inflammation in NMOSD. The serum sCD40L concentrations were not changed after treatment with immunoglobulins, plasma exchange, or methylprednisolone in acute attacks of NMOSD.

Blood Brain Barrier Permeability Could Be a Biomarker to Predict Severity of Neuromyelitis Optica Spectrum Disorders: A Retrospective Analysis

Background: Blood-brain barrier (BBB) pathology exists in neuromyelitis optica spectrum disorders (NMOSD). However, the clinical use of BBB permeability, such as predicting disease severity of NMOSD, has rarely been studied in a large cohort of patients.

Objectives: The current study explored the association between BBB permeability and clinical parameters in order to assess if BBB permeability could be a biomarker to predict disease severity and clinical characteristics of NMOSD.

Methods: Among 69 enrolled NMOSD patients, 47 with albumin index over 5 × 10⁻³ were assigned to the increased BBB permeability group, and the remaining 22 were to the normal BBB permeability group. Disease severity was assessed using the Expanded Disability Status Scale (EDSS).

Results: Patients in the increased BBB permeability group had significantly higher EDSS scores, anti-aquporin-4 immunoglobulin G titers, more dense cerebrospinal fluid protein concentrations, white blood cell counts, myelin basic protein levels and more dense complement 3 concentrations than found in the comparative normal BBB permeability group. The albumin index was positively correlated to the length of lesions in spinal cord.

Conclusions: BBB permeability was associated with clinical features, laboratory results and radiological data of NMOSD patients, and may be a potential biomarker to predict disease severity and clinical characteristics of NMOSD.