scholarly journals Autoantibodies Against the Complement Regulator Factor H in the Serum of Patients With Neuromyelitis Optica Spectrum Disorder

2021 ◽  
Vol 12 ◽  
Author(s):  
Barbara Uzonyi ◽  
Zsóka Szabó ◽  
Eszter Trojnár ◽  
Satu Hyvärinen ◽  
Katalin Uray ◽  
...  
Keyword(s):  
Neuromyelitis Optica ◽  
Alternative Pathway ◽  
Atypical Hemolytic Uremic Syndrome ◽  
Water Channel ◽  
Factor H ◽  
Spectrum Disorder ◽  
Neuromyelitis Optica Spectrum Disorder ◽  
Factor B ◽  
Complement Regulator ◽  
Activating Autoantibodies

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system (CNS), characterized by pathogenic, complement-activating autoantibodies against the main water channel in the CNS, aquaporin 4 (AQP4). NMOSD is frequently associated with additional autoantibodies and antibody-mediated diseases. Because the alternative pathway amplifies complement activation, our aim was to evaluate the presence of autoantibodies against the alternative pathway C3 convertase, its components C3b and factor B, and the complement regulator factor H (FH) in NMOSD. Four out of 45 AQP4-seropositive NMOSD patients (~9%) had FH autoantibodies in serum and none had antibodies to C3b, factor B and C3bBb. The FH autoantibody titers were low in three and high in one of the patients, and the avidity indexes were low. FH-IgG complexes were detected in the purified IgG fractions by Western blot. The autoantibodies bound to FH domains 19-20, and also recognized the homologous FH-related protein 1 (FHR-1), similar to FH autoantibodies associated with atypical hemolytic uremic syndrome (aHUS). However, in contrast to the majority of autoantibody-positive aHUS patients, these four NMOSD patients did not lack FHR-1. Analysis of autoantibody binding to FH19-20 mutants and linear synthetic peptides of the C-terminal FH and FHR-1 domains, as well as reduced FH, revealed differences in the exact binding sites of the autoantibodies. Importantly, all four autoantibodies inhibited C3b binding to FH. In conclusion, our results demonstrate that FH autoantibodies are not uncommon in NMOSD and suggest that generation of antibodies against complement regulating factors among other autoantibodies may contribute to the complement-mediated damage in NMOSD.

Eculizumab in the treatment of neuromyelitis optica spectrum disorder

Immunotherapy ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 1053-1066
Author(s):  
Katrin Giglhuber ◽  
Achim Berthele
Keyword(s):  
Neuromyelitis Optica ◽  
Controlled Trial ◽  
Water Channel ◽  
Spectrum Disorder ◽  
Phase Iii ◽  
Neuromyelitis Optica Spectrum Disorder ◽  
Humanized Monoclonal Antibody ◽  
The Complement System ◽  
Terminal Complement ◽  
Aqp4 Antibody

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the CNS which is distinct from multiple sclerosis and typically presents with a relapsing course of optic neuritis, myelitis and midline brain inflammatory lesions. In at least two-thirds of cases, antibodies against the water channel AQP4 can be found, which lead to an antibody-mediated activation of the complement system with consecutive damage to neuronal structures. Eculizumab, a humanized monoclonal antibody against the terminal complement component 5, was shown to significantly reduce the risk of NMOSD relapse in a Phase III placebo-controlled trial. Based on this, eculizumab (Soliris®) was the first drug to be formally approved for the treatment of anti-AQP4-antibody positive NMOSD in 2019.

scholarly journals Neuromyelitis Optica Spectrum Disorder and Anti-MOG Syndromes

Biomedicines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 42 ◽  
Author(s):  
Marco A. Lana-Peixoto ◽  
Natália Talim
Keyword(s):  
Optic Neuritis ◽  
Neuromyelitis Optica ◽  
Area Postrema ◽  
Water Channel ◽  
Clinical Manifestations ◽  
Transverse Myelitis ◽  
Myelin Oligodendrocyte Glycoprotein ◽  
Immunosuppressive Drugs ◽  
Spectrum Disorder ◽  
Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) and anti-myelin oligodendrocyte glycoprotein (anti-MOG) syndromes are immune-mediated inflammatory conditions of the central nervous system that frequently involve the optic nerves and the spinal cord. Because of their similar clinical manifestations and habitual relapsing course they are frequently confounded with multiple sclerosis (MS). Early and accurate diagnosis of these distinct conditions is relevant as they have different treatments. Some agents used for MS treatment may be deleterious to NMOSD. NMOSD is frequently associated with antibodies which target aquaporin-4 (AQP4), the most abundant water channel in the CNS, located in the astrocytic processes at the blood-brain barrier (BBB). On the other hand, anti-MOG syndromes result from damage to myelin oligodendrocyte glycoprotein (MOG), expressed on surfaces of oligodendrocytes and myelin sheaths. Acute transverse myelitis with longitudinally extensive lesion on spinal MRI is the most frequent inaugural manifestation of NMOSD, usually followed by optic neuritis. Other core clinical characteristics include area postrema syndrome, brainstem, diencephalic and cerebral symptoms that may be associated with typical MRI abnormalities. Acute disseminated encephalomyelitis and bilateral or recurrent optic neuritis are the most frequent anti-MOG syndromes in children and adults, respectively. Attacks are usually treated with steroids, and relapses prevention with immunosuppressive drugs. Promising emerging therapies for NMOSD include monoclonal antibodies and tolerization.

scholarly journals Metabolomic Profiling in Neuromyelitis Optica Spectrum Disorder Biomarker Discovery

Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 374
Author(s):  
Maxton E. Thoman ◽  
Susan C. McKarns
Keyword(s):  
Neuromyelitis Optica ◽  
Biomarker Discovery ◽  
Clinical Symptoms ◽  
Water Channel ◽  
Short Chain Fatty Acids ◽  
Spectrum Disorder ◽  
Neuromyelitis Optica Spectrum Disorder ◽  
Specific Test ◽  
Metabolomic Profiling ◽  
The Central Nervous System

There is no specific test for diagnosing neuromyelitis optica spectrum disorder (NMOSD), a disabling autoimmune disease of the central nervous system. Instead, diagnosis relies on ruling out other related disorders with overlapping clinical symptoms. An urgency for NMOSD biomarker discovery is underscored by adverse responses to treatment following misdiagnosis and poor prognosis following the delayed onset of treatment. Pathogenic autoantibiotics that target the water channel aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) contribute to NMOSD pathology. The importance of early diagnosis between AQP4-Ab+ NMOSD, MOG-Ab+ NMOSD, AQP4-Ab− MOG-Ab− NMOSD, and related disorders cannot be overemphasized. Here, we provide a comprehensive data collection and analysis of the currently known metabolomic perturbations and related proteomic outcomes of NMOSD. We highlight short chain fatty acids, lipoproteins, amino acids, and lactate as candidate diagnostic biomarkers. Although the application of metabolomic profiling to individual NMOSD patient care shows promise, more research is needed.

scholarly journals Hyperfunctional C3 convertase leads to complement deposition on endothelial cells and contributes to atypical hemolytic uremic syndrome

Blood ◽  
2009 ◽  
Vol 114 (13) ◽  
pp. 2837-2845 ◽  
Author(s):  
Lubka T. Roumenina ◽  
Mathieu Jablonski ◽  
Christophe Hue ◽  
Jacques Blouin ◽  
Jordan D. Dimitrov ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Hemolytic Uremic Syndrome ◽  
Umbilical Vein ◽  
Alternative Pathway ◽  
Atypical Hemolytic Uremic Syndrome ◽  
Factor H ◽  
Immune Defense ◽  
Factor B ◽  
Uremic Syndrome ◽  
Complement Deposition

Abstract Complement is a major innate immune defense against pathogens, tightly regulated to prevent host tissue damage. Atypical hemolytic uremic syndrome (aHUS) is characterized by endothelial damage leading to renal failure and is highly associated with abnormal alternative pathway regulation. We characterized the functional consequences of 2 aHUS-associated mutations (D254G and K325N) in factor B, a key participant in the alternative C3 convertase. Mutant proteins formed high-affinity C3-binding site, leading to a hyperfunctional C3 convertase, resistant to decay by factor H. This led to enhanced complement deposition on the surface of alternative pathway activator cells. In contrast to native factor B, the 2 mutants bound to inactivated C3 and induced formation of functional C3-convertase on iC3b-coated surface. We demonstrated for the first time that factor B mutations lead to enhanced C3-fragment deposition on quiescent and adherent human glomerular cells (GEnCs) and human umbilical vein endothelial cells (HUVECs), together with the formation of sC5b-9 complexes. These results could explain the occurrence of the disease, since excessive complement deposition on endothelial cells is a central event in the pathogenesis of aHUS. Therefore, risk factors for aHUS are not only mutations leading to loss of regulation, but also mutations, resulting in hyperactive C3 convertase.

Association of cigarette smoking with neuromyelitis opticaimmunoglobulin G sero-positivity in neuromyelitis optica spectrum disorder

2019 ◽  
Author(s):  
Sharareh Eskandarieh ◽  
Abdorreza Naser Moghadasi ◽  
Mohammad Ali Sahraiain ◽  
Amir Reza Azimi ◽  
Negar Molazadeh
Keyword(s):  
Cigarette Smoking ◽  
Neuromyelitis Optica ◽  
Demyelinating Disease ◽  
Water Channel ◽  
Cross Sectional Study ◽  
Spectrum Disorder ◽  
Enzyme Linked Immunosorbent Assay ◽  
Neuromyelitis Optica Spectrum Disorder ◽  
Cross Sectional ◽  
Tertiary Referral Center

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a neuroinflammatory demyelinating disease caused by the presence of a highly specific serum autoantibody marker, NMO-immunoglobulin G (NMO-IgG), that reacts against the water channel aquaporin-4 (AQP4). The present study examined the association between NMO-IgG sero-positivity and environmental factors such as cigarette smoking. Methods: A cross-sectional study was conducted in Sina Hospital, a tertiary referral center in Tehran, Iran. All the patients with a definite diagnosis of NMOSD were involved in this study. The enzyme-linked immunosorbent assay (ELISA) was used to examine the AQP4-IgG status. To assess the association between NMO-IgG sero-positivity and cigarette smoking, a researcher-made questionnaire covering patients’ lifestyle information on smoking habits was designed and administered using the structured face-to-face interviews with the patients. Results: The positive and negative NMO-IgG results were found in 44 (46.8%) and 50 (53.2%) patients, respectively. The increased NMO-IgG sero-positivity odds were observed among the lifetime smokers [odds ratio (OR) = 3.24, 95% confidence interval (CI): 1.16-9.08], current smokers (OR = 6.08, 95% CI: 1.26-29.39), and passive smokers (OR = 2.22, 95% CI: 1.10-4.50). Conclusion: Lifetime and current smoking as well as passive smoking can be regarded as risk factors for NMO-IgG sero-positivity. Smoking with its immunological effects can lead to the production of autoantibodies such as NMO-IgG. 

scholarly journals Cytoprotective IgG antibodies in sera from a subset of patients with AQP4-IgG seropositive neuromyelitis optica spectrum disorder

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lukmanee Tradtrantip ◽  
Michael R. Yeaman ◽  
A. S. Verkman
Keyword(s):  
Neuromyelitis Optica ◽  
Protective Factor ◽  
Water Channel ◽  
Spectrum Disorder ◽  
Aquaporin 4 ◽  
Neuromyelitis Optica Spectrum Disorder ◽  
Igg Antibody ◽  
Igg Binding ◽  
Complement Dependent Cytotoxicity ◽  
Wide Range

AbstractNeuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system. Most NMOSD patients are seropositive for immunoglobulin G (IgG) autoantibodies against astrocyte water channel aquaporin-4 (AQP4), called AQP4-IgG. AQP4-IgG binding to aquaporin-4 causes complement-dependent cytotoxicity (CDC), leading to inflammation and demyelination. Here, CDC was measured in AQP4-expressing cells exposed to human complement and heat-inactivated sera from 108 AQP4-IgG seropositive NMOSD subjects and 25 non-NMOSD controls. AQP4-IgG positive sera produced a wide range of CDC, with 50% maximum cytotoxicity produced by as low as 0.2% serum concentration. Unexpectedly, 58 samples produced no cytotoxicity, and of those, four sera were cytoprotective against cytotoxic AQP4-IgG. Cytoprotection was found against different cytotoxic monoclonal AQP4-IgGs and NMOSD patient sera, and in primary astrocyte cultures. Mechanistic studies revealed that the protective factor is an IgG antibody that did not inhibit complement directly, but interfered with binding of cytotoxic AQP4-IgG to AQP4 and consequent C1q binding and complement activation. Further studies suggested that non-pathogenic AQP4-IgG, perhaps with altered glycosylation, may contribute to reduced or ineffectual binding of cytotoxic AQP4-IgG, as well as reduced cell-surface AQP4. The presence of natural cytoprotective antibodies in AQP4-IgG seropositive sera reveals an added level of complexity in NMOSD disease pathogenesis, and suggests the potential therapeutic utility of ‘convalescent’ serum or engineered protective antibody to interfere with pathogenic antibody in AQP4-IgG seropositive NMOSD.

scholarly journals Paraneoplastic Neuromyelitis Optica Spectrum Disorder Associated With Lung Adenocarcinoma: A Case Report

2022 ◽  
Vol 8 ◽  
Author(s):  
Carlo Maiorca ◽  
Federica Moret ◽  
Valentina Martines ◽  
Daniele Tramontano ◽  
Maria Alessia Papassifachis ◽  
...  
Keyword(s):  
Neuromyelitis Optica ◽  
Brain Mri ◽  
Water Channel ◽  
Clinical Signs ◽  
Transverse Myelitis ◽  
Spectrum Disorder ◽  
Whole Body ◽  
Parietal Pleura ◽  
High Dose ◽  
Neuromyelitis Optica Spectrum Disorder

Neuromyelitis Optica spectrum disorder is an inflammatory demyelinating disease affecting the central nervous system (CNS), characterized by triad optic neuritis, transverse myelitis, and area postrema syndrome. Antibodies directed against aquaporin-4 (AQP-4), a water channel expressed on the astrocytic membrane, are supposed to play a pathogenic role and are detected in ~80% of cases. Clinical signs of Neuromyelitis Optica spectrum disorder (NMOSD) in elderly patients should arouse the suspicion of paraneoplastic etiology. In this article, we discussed a case of a 76-year-old woman with a 2-month history of confusion, dysarthria, and progressive bilateral leg weakness. A whole-body CT scan showed a neoformation of 5 cm in diameter in the median lobe infiltrating the mediastinal pleura. The tumor had already spread to both the upper and lower right lobes, parietal pleura, and multiple lymph nodes. Pleural cytology revealed adenocarcinoma cells. The brain MRI documented hyperintense alteration in fluid-attenuated inversion recovery (FLAIR) images, involving the anterior portion of the corpus callosum and the periependymal white matter surrounding the lateral ventricles, with mild contrast enhancement on the same areas and meningeal tissue. T2-weighted spinal cord MRI sequences showed extended signal hyperintensity from bulbo-cervical junction to D7 metamer, mainly interesting the central component and the gray matter. Cerebrospinal fluid analysis revealed no neoplastic cells. Serum AQP-4 immunoglobulin (IgG) antibodies were found. Meanwhile, the patient rapidly developed progressive paraparesis and decreased level of consciousness. High-dose intravenous methylprednisolone therapy was started but her conditions rapidly deteriorated. No other treatment was possible.

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