BACKGROUND: Previous studies have indicated that progression independent of relapse activity (PIRA) is uncommon in patients with aquaporin- 4 antibody-positive (AQP4-IgG) neuromyelitis optica spectrum disorder (NMOSD). However, the patterns of disability accumulation in seronegative NMOSD are unknown. This study aimed to evaluate the prevalence of PIRA and relapse-associated worsening (RAW) in seronegative NMOSD. METHODS: We conducted a retrospective, multicentre cohort study of seronegative NMOSD patients from the MSBase registry. Inclusion criteria required at least three recorded expanded disability status scale (EDSS) scores: baseline, progression, and 6 months confirmed disability progression (CDP). For those with 6-month CDP, the presence or absence of relapse between baseline and progression determined the classification as RAW or PIRA, respectively. Descriptive statistics were employed to present the data. RESULTS: This study included 93 patients, with a median follow-up duration of 5.0 years (Q1 2.8, Q3 8.4). The cohort predominantly consisted of female patients (77.4%), with a median age of onset of 33.9 years (Q1 26.1, Q3 41.2). PIRA was observed in 1 case (1.1%), whilst RAW was documented in 7 cases (7.5%). CONCLUSION: This international cohort study confirms that CDP is uncommon in seronegative NMOSD. Given more than three quarters of CDP occur due to RAW, therapeutic strategies should focus primarily on preventing relapses.

• Klíčová slova
• Disability, EDSS, NMOSD, Progression independent of relapses, Relapse-associated worsening, Seronegative,
• MeSH
• akvaporin 4 imunologie   MeSH
• autoprotilátky krev   MeSH
• dospělí MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• následné studie MeSH
• neuromyelitis optica * patofyziologie   epidemiologie   krev   imunologie   MeSH
• posuzování pracovní neschopnosti MeSH
• progrese nemoci * MeSH
• recidiva MeSH
• registrace MeSH
• retrospektivní studie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• Názvy látek
• akvaporin 4 MeSH
• AQP4 protein, human MeSH Prohlížeč
• autoprotilátky MeSH

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) can be categorised into aquaporin-4 antibody (AQP4-IgG) NMOSD or seronegative NMOSD. While our knowledge of AQP4-IgG NMOSD has evolved significantly in the past decade, seronegative NMOSD remains less understood. This study aimed to evaluate the predictors of relapses and treatment responses in AQP4-IgG NMOSD and seronegative NMOSD. METHODS: This was a multicentre, international, retrospective cohort study using the MSBase registry. Recurrent relapse risk was assessed using an Andersen-Gill model and risk of first relapse was evaluated using a Cox proportional hazards model. Covariates that putatively influence relapse risk included demographic factors, clinical characteristics and immunosuppressive therapies; the latter was assessed as a time-varying covariate. RESULTS: A total of 398 patients (246 AQP4-IgG NMOSD and 152 seronegative NMOSD) were included. The AQP4-IgG NMOSD and seronegative NMOSD patients did not significantly differ by age at disease onset, ethnicity or annualised relapse rate. Both low-efficacy and high-efficacy immunosuppressive therapies were associated with significant reductions in recurrent relapse risk, with notably greater protection conferred by high-efficacy therapies in both AQP4-IgG NMOSD (HR 0.27, 95% CI 0.15 to 0.49, p<0.001) and seronegative NMOSD (HR 0.21, 95% CI 0.08 to 0.51, p<0.001). Longer disease duration (HR 0.97, 95% CI 0.95 to 0.99, p<0.001) and male sex (HR 0.52, 95% CI 0.34 to 0.84, p=0.007) were additional protective variables in reducing the recurrent relapse risk for the AQP4-IgG NMOSD group. CONCLUSION: Although further studies are needed to improve our understanding of seronegative NMOSD, our findings underscore the importance of aggressive treatment with high-efficacy immunotherapies in both NMOSD subtypes, regardless of serostatus.

• Klíčová slova
• HEALTH ECONOMICS, IMMUNOLOGY, MEDICINE, MULTIPLE SCLEROSIS, NEUROIMMUNOLOGY,
• MeSH
• akvaporin 4 * imunologie   MeSH
• autoprotilátky * krev   MeSH
• dospělí MeSH
• imunoglobulin G * krev   imunologie   MeSH
• imunosupresiva terapeutické užití   MeSH
• lidé středního věku MeSH
• lidé MeSH
• neuromyelitis optica * imunologie   farmakoterapie   terapie   MeSH
• proporcionální rizikové modely MeSH
• recidiva MeSH
• retrospektivní studie MeSH
• rizikové faktory MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• Názvy látek
• akvaporin 4 * MeSH
• AQP4 protein, human MeSH Prohlížeč
• autoprotilátky * MeSH
• imunoglobulin G * MeSH
• imunosupresiva MeSH

OBJECTIVES: In aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-IgG NMOSD), disability accrual is mostly attributed to relapses. This study aimed to assess the prevalence of progression independent of relapse activity (PIRA) and relapse-associated worsening (RAW) in AQP4-IgG NMOSD. METHODS: This was a retrospective cohort study of patients with AQP4-IgG NMOSD enrolled in the MSBase international data registry. Patients required a minimum of 3 recorded Expanded Disability Status Scale (EDSS) scores: baseline, event, and a 6-month confirmation score. Presence and absence of relapses between the baseline and event EDSS scores determined RAW and PIRA, respectively. Descriptive statistics were used to present the results. RESULTS: A total of 181 patients followed for a median of 4.5 years (Q1 1.7, Q3 7.8) were included. Most patients were female (88.4%), and the median age at disease onset was 38.1 years. Overall, 4 patients (2.2%) developed 5 incidences of PIRA and 13 patients developed RAW (7.2%). DISCUSSION: This multicenter study highlights that PIRA is very rare in AQP4-IgG NMOSD. Limitations of this study include the sole focus of overall EDSS to measure disability, lack of requirement for a second EDSS score to confirm baseline EDSS, and the absence of magnetic resonance imaging information for all patients.

• MeSH
• akvaporin 4 * imunologie   MeSH
• autoprotilátky * krev   MeSH
• dospělí MeSH
• imunoglobulin G * krev   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• neuromyelitis optica * imunologie   epidemiologie   MeSH
• posuzování pracovní neschopnosti MeSH
• prevalence MeSH
• progrese nemoci * MeSH
• recidiva * MeSH
• retrospektivní studie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• pozorovací studie MeSH
• Názvy látek
• akvaporin 4 * MeSH
• AQP4 protein, human MeSH Prohlížeč
• autoprotilátky * MeSH
• imunoglobulin G * MeSH

Astrocytes are specialized glial cell types of the central nervous system (CNS) with remarkably high abundance, morphological and functional diversity. Astrocytes maintain neural metabolic support, synapse regulation, blood-brain barrier integrity and immunological homeostasis through intricate interactions with other cells, including neurons, microglia, pericytes and lymphocytes. Due to their extensive intercellular crosstalks, astrocytes are also implicated in the pathogenesis of CNS disorders, such as ALS (amyotrophic lateral sclerosis), Parkinson's disease and Alzheimer's disease. Despite the critical importance of astrocytes in neurodegeneration and neuroinflammation are recognized, the lack of suitable in vitro systems limits their availability for modeling human brain pathologies. Here, we report the time-efficient, reproducible generation of astrocytes from human induced pluripotent stem cells (hiPSCs). Our hiPSC-derived astrocytes expressed characteristic astrocyte markers, such as GFAP, S100b, ALDH1L1 and AQP4. Furthermore, hiPSC-derived astrocytes displayed spontaneous calcium transients and responded to inflammatory stimuli by the secretion of type A1 and type A2 astrocyte-related cytokines.

• MeSH
• akvaporin 4 metabolismus   MeSH
• astrocyty * cytologie   metabolismus   MeSH
• buněčná diferenciace * MeSH
• cytokiny metabolismus   MeSH
• gliový fibrilární kyselý protein metabolismus   MeSH
• indukované pluripotentní kmenové buňky * cytologie   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• S-100 kalcium vázající protein G, podjednotka beta * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• akvaporin 4 MeSH
• cytokiny MeSH
• gliový fibrilární kyselý protein MeSH
• S-100 kalcium vázající protein G, podjednotka beta * MeSH
• S100B protein, human MeSH Prohlížeč

A subpopulation of astrocytes on the brain's surface, known as subpial astrocytes, constitutes the "glia limitans superficialis" (GLS), which is an interface between the brain parenchyma and the cerebrospinal fluid (CSF) in the subpial space. Changes in connexin-43 (Cx43) and aquaporin-4 (AQP4) proteins in subpial astrocytes were examined in the medial prefrontal cortex at postoperative day 1, 3, 7, 14, and 21 after sham operation and sciatic nerve compression (SNC). In addition, we tested the altered uptake of TRITC-conjugated 3 kDa dextran by reactive subpial astrocytes. Cellular immunofluorescence (IF) detection and image analysis were used to examine changes in Cx43 and AQP4 protein levels, as well as TRITC-conjugated 3 kDa dextran, in subpial astrocytes. The intensity of Cx43-IF was significantly increased, but AQP4-IF decreased in subpial astrocytes of sham- and SNC-operated rats during all survival periods compared to naïve controls. Similarly, the uptake of 3 kDa dextran in the GLS was reduced following both sham and SNC operations. The results suggest that both sciatic nerve injury and peripheral tissue injury alone can induce changes in subpial astrocytes related to the spread of their reactivity across the cortical surface mediated by increased amounts of gap junctions. At the same time, water transport and solute uptake were impaired in subpial astrocytes.

• Klíčová slova
• aquaporins, astrocytes, fluoro-ruby, gap junction, image analysis, in situ proteomics, nerve injury, reactivity, tissue injury,
• MeSH
• akvaporin 4 * metabolismus   MeSH
• astrocyty * metabolismus   MeSH
• dextrany * metabolismus   MeSH
• konexin 43 * metabolismus   MeSH
• krysa rodu Rattus MeSH
• nervus ischiadicus * zranění   metabolismus   MeSH
• potkani Sprague-Dawley MeSH
• prefrontální mozková kůra * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• akvaporin 4 * MeSH
• Aqp4 protein, rat MeSH Prohlížeč
• dextrany * MeSH
• konexin 43 * MeSH

BACKGROUND: The expression of aquaporin 4 (AQP4) and intermediate filament (IF) proteins is altered in malignant glioblastoma (GBM), yet the expression of the major IF-based cytolinker, plectin (PLEC), and its contribution to GBM migration and invasiveness, are unknown. Here, we assessed the contribution of plectin in affecting the distribution of plasmalemmal AQP4 aggregates, migratory properties, and regulation of cell volume in astrocytes. METHODS: In human GBM, the expression of glial fibrillary acidic protein (GFAP), AQP4 and PLEC transcripts was analyzed using publicly available datasets, and the colocalization of PLEC with AQP4 and with GFAP was determined by immunohistochemistry. We performed experiments on wild-type and plectin-deficient primary and immortalized mouse astrocytes, human astrocytes and permanent cell lines (U-251 MG and T98G) derived from a human malignant GBM. The expression of plectin isoforms in mouse astrocytes was assessed by quantitative real-time PCR. Transfection, immunolabeling and confocal microscopy were used to assess plectin-induced alterations in the distribution of the cytoskeleton, the influence of plectin and its isoforms on the abundance and size of plasmalemmal AQP4 aggregates, and the presence of plectin at the plasma membrane. The release of plectin from cells was measured by ELISA. The migration and dynamics of cell volume regulation of immortalized astrocytes were assessed by the wound-healing assay and calcein labeling, respectively. RESULTS: A positive correlation was found between plectin and AQP4 at the level of gene expression and protein localization in tumorous brain samples. Deficiency of plectin led to a decrease in the abundance and size of plasmalemmal AQP4 aggregates and altered distribution and bundling of the cytoskeleton. Astrocytes predominantly expressed P1c, P1e, and P1g plectin isoforms. The predominant plectin isoform associated with plasmalemmal AQP4 aggregates was P1c, which also affected the mobility of astrocytes most prominently. In the absence of plectin, the collective migration of astrocytes was impaired and the dynamics of cytoplasmic volume changes in peripheral cell regions decreased. Plectin's abundance on the plasma membrane surface and its release from cells were increased in the GBM cell lines. CONCLUSIONS: Plectin affects cellular properties that contribute to the pathology of GBM. The observed increase in both cell surface and released plectin levels represents a potential biomarker and therapeutic target in the diagnostics and treatment of GBMs.

• Klíčová slova
• Aquaporin 4, Astrocyte, Cell migration, Cell volume, Cytoskeleton, Edema, Glioblastoma, Intermediate filaments, Plectin,
• MeSH
• akvaporin 4 MeSH
• astrocyty MeSH
• biologické markery MeSH
• glioblastom * MeSH
• lidé MeSH
• myši MeSH
• plektin MeSH
• protein - isoformy MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• akvaporin 4 MeSH
• biologické markery MeSH
• Plec protein, mouse MeSH Prohlížeč
• plektin MeSH
• protein - isoformy MeSH

Inebilizumab, a humanized, glycoengineered, IgG1 monoclonal antibody that depletes CD19+ B-cells, is approved to treat aquaporin 4 (AQP4) IgG-seropositive neuromyelitis optica spectrum disorder (NMOSD). Inebilizumab is afucosylated and engineered for enhanced affinity to Fc receptor III-A (FCGR3A) receptors on natural killer cells to maximize antibody-dependent cellular cytotoxicity. Previously, the F allele polymorphism at amino acid 158 of the FCGR3A gene (F158) was shown to decrease IgG-binding affinity and reduce rituximab (anti-CD20) efficacy for NMOSD attack prevention. In contrast, our current findings from inebilizumab-treated NMOSD patients indicate similar clinical outcomes between those with F158 and V158 allele genotypes.

• MeSH
• akvaporin 4 genetika   MeSH
• humanizované monoklonální protilátky terapeutické užití   MeSH
• imunoglobulin G MeSH
• lidé MeSH
• neuromyelitis optica * farmakoterapie   genetika   MeSH
• receptory IgG genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• akvaporin 4 MeSH
• FCGR3A protein, human MeSH Prohlížeč
• humanizované monoklonální protilátky MeSH
• imunoglobulin G MeSH
• inebilizumab MeSH Prohlížeč
• receptory IgG MeSH

There is no consensus regarding the classification of optic neuritis, and precise diagnostic criteria are not available. This reality means that the diagnosis of disorders that have optic neuritis as the first manifestation can be challenging. Accurate diagnosis of optic neuritis at presentation can facilitate the timely treatment of individuals with multiple sclerosis, neuromyelitis optica spectrum disorder, or myelin oligodendrocyte glycoprotein antibody-associated disease. Epidemiological data show that, cumulatively, optic neuritis is most frequently caused by many conditions other than multiple sclerosis. Worldwide, the cause and management of optic neuritis varies with geographical location, treatment availability, and ethnic background. We have developed diagnostic criteria for optic neuritis and a classification of optic neuritis subgroups. Our diagnostic criteria are based on clinical features that permit a diagnosis of possible optic neuritis; further paraclinical tests, utilising brain, orbital, and retinal imaging, together with antibody and other protein biomarker data, can lead to a diagnosis of definite optic neuritis. Paraclinical tests can also be applied retrospectively on stored samples and historical brain or retinal scans, which will be useful for future validation studies. Our criteria have the potential to reduce the risk of misdiagnosis, provide information on optic neuritis disease course that can guide future treatment trial design, and enable physicians to judge the likelihood of a need for long-term pharmacological management, which might differ according to optic neuritis subgroups.

• MeSH
• akvaporin 4 MeSH
• autoprotilátky MeSH
• lidé MeSH
• neuromyelitis optica * diagnóza   MeSH
• retrospektivní studie MeSH
• roztroušená skleróza * komplikace   MeSH
• zánět zrakového nervu * diagnóza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• akvaporin 4 MeSH
• autoprotilátky MeSH

BACKGROUND: Serum antibodies to myelin-oligodendrocyte glycoprotein (MOG) are biomarkers of MOG-IgG-associated disorder (MOGAD), a demyelinating disease distinct from both multiple sclerosis and aquaporin-4-IgG neuromyelitis optica spectrum disorder. The phenotype of MOGAD is broad and includes optic neuritis, transverse myelitis, and acute demyelinating encephalomyelitis. Myelitis is common with MOGAD and typically results in acute and severe disability, although prospects for recovery are often favorable with prompt immunotherapy. CASE PRESENTATION: This contribution presents a unique case report of a young male patient exhibiting relapsing myelitis with normal spinal cord and brain magnetic resonance imaging. Comprehensive diagnostic assessment revealed myelin-oligodendrocyte glycoprotein-IgG-associated disorder. CONCLUSION: MOGAD is one of the conditions which should be considered in MRI-negative myelitis. The diagnosis, however, may prove difficult, especially if the patient is not exhibiting other neurological symptoms of MOGAD. Conus or epiconus involvement is common in MOGAD; the patient reported herein exhibited incomplete rostral epiconus symptoms which, together with somatosensory evoked potential abnormalities, led to the diagnosis.

• Klíčová slova
• Case report, Demyelinating diseases, Evoked potentials, Magnetic resonance imaging, Myelin-oligodendrocyte glycoprotein,
• MeSH
• akvaporin 4 MeSH
• autoprotilátky MeSH
• glykoprotein v myelinu oligodendrocytů MeSH
• imunoglobulin G MeSH
• lidé MeSH
• lokální recidiva nádoru MeSH
• magnetická rezonanční tomografie MeSH
• neuromyelitis optica * MeSH
• transverzální myelitida * diagnostické zobrazování   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• akvaporin 4 MeSH
• autoprotilátky MeSH
• glykoprotein v myelinu oligodendrocytů MeSH
• imunoglobulin G MeSH

BACKGROUND: The N-MOmentum trial, a double-blind, randomized, placebo-controlled, phase 2/3 study of inebilizumab in neuromyelitis optica spectrum disorder (NMOSD), enrolled participants who were aquaporin-4-immunoglobulin G (AQP4-IgG)-seropositive (AQP4+) or -seronegative (AQP4-). This article reports AQP4- participant outcomes. METHODS: AQP4-IgG serostatus was determined for all screened participants by a central laboratory, using a validated, fluorescence-observation cell-binding assay. Medical histories and screening data for AQP4- participants were assessed independently by an eligibility committee of three clinical experts during screening. Diagnosis of NMOSD was confirmed by majority decision using the 2006 neuromyelitis optica criteria. Myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG) serology (using a clinically validated, flow cytometry assay) and annualized attack rates (AARs) were evaluated post hoc. Efficacy outcomes were assessed by comparing pre-study and on-study AARs in treated participants. RESULTS: Only 18/50 AQP4- screened participants (36%) were initially considered eligible for randomization; 16 were randomized and received full treatment, 4 to placebo (1 MOG-IgG-seropositive [MOG+]) and 12 to inebilizumab (6 MOG+). The most common reason for failure to pass screening among prospective AQP4- participants was failure to fulfill the 2006 NMO MRI criteria. In inebilizumab-treated AQP4- participants, on-study AARs (95% confidence interval [CI]) calculated from treatment initiation (whether from randomization or when received at the start of the open-label period) to the end of study were lower than pre-study rates: for all AQP4- participants (n = 16), mean (95% CI) AAR was 0.048 (0.02-0.15) versus 1.70 (0.74-2.66), respectively. For the subset of AQP4-/MOG+ participants (n = 7), AAR was 0.043 (0.006-0.302) after treatment versus 1.93 (1.10-3.14) before the study. For the subset of AQP4-/MOG- participants (n = 9), post-treatment AAR was 0.051 (0.013-0.204) versus 1.60 (1.02-2.38). Three attacks occurred during the randomized controlled period in the AQP4- inebilizumab group and were of mild severity; no attacks occurred in the AQP4- placebo group. The low number of participants receiving placebo (n = 4) confounds direct comparison with the inebilizumab group. No attacks were seen in any AQP4- participant after the second infusion of inebilizumab. Inebilizumab was generally well tolerated by AQP4- participants and the adverse event profile observed was similar to that of AQP4+ participants. CONCLUSION: The high rate of rejection of AQP4- participants from enrollment into the study highlights the challenges of implementing the diagnostic criteria of AQP4- NMOSD. An apparent reduction of AAR in participants with AQP4- NMOSD who received inebilizumab warrants further investigation.

• Klíčová slova
• Neuromyelitis optica spectrum disorder, annualized attack rate, aquaporin-4-IgG-seronegative, clinical trial, inebilizumab, myelin oligodendrocyte glycoprotein-IgG-seropositive,
• MeSH
• akvaporin 4 MeSH
• autoprotilátky MeSH
• humanizované monoklonální protilátky MeSH
• imunoglobulin G MeSH
• lidé MeSH
• neuromyelitis optica * diagnostické zobrazování   farmakoterapie   MeSH
• prospektivní studie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• akvaporin 4 MeSH
• autoprotilátky MeSH
• humanizované monoklonální protilátky MeSH
• imunoglobulin G MeSH
• inebilizumab MeSH Prohlížeč