Aquaporin-4 Removal from the Plasma Membrane of Human Müller Cells by AQP4-IgG from Patients with Neuromyelitis Optica Induces Changes in Cell Volume Homeostasis: the First Step of Retinal Injury?

Aquaporin-4 (AQP4) is the target of the specific immunoglobulin G autoantibody (AQP4-IgG) produced in patients with neuromyelitis optica spectrum disorders (NMOSD). Previous studies demonstrated that AQP4-IgG binding to astrocytic AQP4 leads to cell-destructive lesions. However, the early physiopathological events in Müller cells in the retina are poorly understood. Here, we investigated the consequences of AQP4-IgG binding to AQP4 of Müller cells, previous to the inflammatory response, on two of AQP4's key functions, cell volume regulation response (RVD) and cell proliferation, a process closely associated with changes in cell volume. Experiments were performed in a human retinal Müller cell line (MIO-M1) exposed to complement-inactivated sera from healthy volunteers or AQP4-IgG positive NMOSD patients. We evaluated AQP4 expression (immunofluorescence and western blot), water permeability coefficient, RVD, intracellular calcium levels and membrane potential changes during hypotonic shock (fluorescence videomicroscopy) and cell proliferation (cell count and BrdU incorporation). Our results showed that AQP4-IgG binding to AQP4 induces its partial internalization, leading to the decrease of the plasma membrane water permeability, a reduction of swelling-induced increase of intracellular calcium levels and the impairment of RVD in Müller cells. The loss of AQP4 from the plasma membrane induced by AQP4-IgG positive sera delayed Müller cells' proliferation rate. We propose that Müller cell dysfunction after AQP4 removal from the plasma membrane by AQP4-IgG binding could be a non-inflammatory mechanism of retinal injury in vivo, altering cell volume homeostasis and cell proliferation and consequently, contributing to the physiopathology of NMOSD.

An Abnormally High Neutrophil-to-Lymphocyte Ratio Is Not an Independent Outcome Predictor in AQP4-IgG-Positive NMOSD.

Background: The neutrophil-to-lymphocyte ratio (NLR) has been investigated in many autoimmune conditions as a biomarker of inflammation and/or disease activity. The role of NLR in AQP4-IgG-positive neuromyelitis optica spectrum disorders (NMOSD) is far from clear. In this study, NLR was evaluated in patients with AQP4-IgG-positive NMOSD at disease onset and its prognostic impact was subsequently assessed. Methods: In this multicenter study, we retrospectively included all recent/newly diagnosed treatment-naïve patients with AQP4-IgG-positive NMOSD (n=90) from three different countries in Latin America (LATAM): Argentina, Ecuador, and Mexico. NLR was compared between AQP4-IgG-positive NMOSD and healthy controls (HC, n = 365). Demographic, clinical, paraclinical (including imaging), and prognostic data at 12 and 24 months were also evaluated. Multivariate regression analysis was used to describe and identify independent associations between the log-transformed NLR and clinical (relapses and EDSS) and imaging (new/enlarging and/or contrast-enhancing MRI lesions) outcomes. Results: NLR was higher in NMOSD patients during the first attack compared with HC (2.9 ± 1.6 vs 1.8 ± 0.6; p<0.0001). Regardless of immunosuppressant's initiation at disease onset, NLR remained higher in NMOSD patients at 12 (2.8 ± 1.3; p<0.0001) and 24 (3.1 ± 1.6; p<0.0001) months. No association was found at 12 and 24 months between the log-transformed NLR and the presence of relapses, new/enlarging and/or contrast-enhancing MRI lesions, and/or physical disability. Conclusions: In this cohort of LATAM patients with AQP4-IgG-positive NMOSD, NLR was abnormally high in attacks but also during follow-up. However, a high NLR was not an independent predictor of clinical or imaging outcomes in our models.

Brain and spinal MRI features distinguishing MS from different AQP4 antibody serostatus NMOSD at disease onset in a cohort of Latin American patients.

OBJECTIVE: We aimed to evaluate magnetic resonance imaging (MRI) previously used criteria (Matthews's criteria, MC) for differentiating multiple sclerosis (MS) from neuromyelitis optica spectrum disorders (NMOSD) in Caucasian and non-Caucasian populations (Argentina, Brazil and Venezuela) with positive (P-NMOSD), negative (N-NMOSD), and unknown (U-NMOSD) aquaporin-4 antibody serostatus at disease onset and to assess the added diagnostic value of spinal cord MRI in these populations. METHODS: We reviewed medical records, and MRIs were assessed by two blinded evaluators and were scored using MC. Short-segment transverse myelitis (STM) was added as a new criterion. MC sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined. RESULTS: We included 282 patients (MS = 188 and NMOSD = 94). MC applied to the entire cohort showed 97.8% sensitivity, 82.9% specificity, 92.0% PPV, and 95.1% NPV for differentiating MS from NMOSD. A subanalysis applied only to non-Caucasian (MS = 89 and NMOSD = 47) showed 100% sensitivity, 80.8% specificity, 90.8% PPV, and 100% NPV. Similar sensitivity, specificity, PPV, and NPV of MC for MS versus P-NMOSD (n = 55), N-NMOSD (n = 28), and U-NMOSD (n = 21) were observed. CONCLUSION: MC distinguished MS from NMOSD of all serostatus in a Latin American cohort that included non-Caucasian populations. Addition of STM to MC did not raise the accuracy significantly.

HLA-G Ins/Del polymorphism and +3142C/G SNP are not related to neuromyelitis optica spectrum disorder (NMOSD) development, disability status or anti-aquaporin 4 presence in Brazilian patients.

We analyzed the association of polymorphisms from the 3' untranslated region of the HLA-G gene in 70 neuromyelitis optica spectrum disorder (NMOSD) patients and 162 healthy controls. No associations were found between the polymorphisms in NMOSD when compared to healthy controls, serology of the anti-AQP4 NMOSD biomarker and Expanded Disability Status Scale (EDSS). In conclusion, the 3' untranslated region 14 bp Ins/Del and +3142C/G polymorphisms seem not to be associated with NMOSD susceptibility, autoantibody production, nor a neurological deficit in patients.

A highly specific and sensitive nanoimmunosensor for the diagnosis of neuromyelitis optica spectrum disorders.

A precise diagnosis for neuromyelitis optica spectrum disorders (NMOSD) is crucial to improve patients' prognostic, which requires highly specific and sensitive tests. The cell-based assay with a sensitivity of 76% and specificity of 100% is the most recommended test to detect anti-aquaporin-4 antibodies (AQP4-Ab). Here, we tested four AQP4 external loop peptides (AQP461-70, AQP4131-140, AQP4141-150, and AQP4201-210) with an atomic force microscopy nanoimmunosensor to develop a diagnostic assay. We obtained the highest reactivity with AQP461-70-nanoimunosensor. This assay was effective in detecting AQP4-Ab in sera of NMOSD patients with 100% specificity (95% CI 63.06-100), determined by the cut-off adhesion force value of 241.3 pN. NMOSD patients were successfully discriminated from a set of healthy volunteers, patients with multiple sclerosis, and AQP4-Ab-negative patients. AQP461-70 sensitivity was 81.25% (95% CI 56.50-99.43), slightly higher than with the CBA method. The results with the AQP461-70-nanoimmunosensor indicate that the differences between NMOSD seropositive and seronegative phenotypes are related to disease-specific epitopes. The absence of AQP4-Ab in sera of NMOSD AQP4-Ab-negative patients may be interpreted by assuming the existence of another potential AQP4 peptide sequence or non-AQP4 antigens as the antibody target.

The expansion of circulating IL-6 and IL-17-secreting follicular helper T cells is associated with neurological disabilities in neuromyelitis optica spectrum disorders.

Due to their function in assisting B cells, TFH cells may be involved in the production of pathogenic IgG in neuromyelitis optica spectrum disorder (NMOSD). In the present study, the proportion of IL-6+ and IL-17+ TFH cell subsets was higher in NMOSD patients than healthy individuals. The frequency of both TFH cell subsets were directly associated with disease activity. By contrast, NMOSD patients with a higher proportion of IL-10+ TFH cell subsets showed a lower neurological disabilities score. In summary, all findings suggest that expansion of peripheral IL-6+ and IL-17+ TFH cells may be involved in the severity of NMOSD.

Obstetric outcomes in a Mexican cohort of patients with AQP4-antibody-seropositive neuromyelitis optica.

BACKGROUND: Previous studies have investigated the influence of neuromyelitis optica (NMO) on pregnancy in other ethnic groups. However, there are potential variations among ethnic groups. The obstetric outcome of Mexican patients with NMO and AQP4-IgG positivity (AQP4-IgG[+]) is currently unknown. OBJECTIVE: To describe the obstetric history of Mexican patients with NMO and AQP4-IgG(+). METHODS: Patients with NMO and AQP4-IgG(+) were identified from the database of the Demyelinating Diseases Clinic. These patients were interviewed by telephone. RESULTS: Out of a total of 40 eligible patients, 29 were contacted and completed the survey. Of these, 19 patients reported at least one previous pregnancy. In total, 50 pregnancies were reported: 44 of them occurred ≥ 3 years before the first clinical manifestation, 1 occurred ≥ 1 years before, and 1 occurred after the first manifestation. Of all pregnancies, 12 were pregnancy losses: 5 were classified as miscarriages and 3 as stillbirths. Of all pregnancy losses, 10 occurred ≥ 3 years before the diagnosis, 1 occurred after the first manifestation. All pregnancy losses occurred in 8 patients. CONCLUSIONS: Close to half of the patients with previous pregnancies reported at least one pregnancy loss, most of these occurred ≥ 3 years before the diagnosis. This percentage is higher than expected for their age group in our country.

Treatment of neuromyelitis optica with rituximab: a 2-year prospective multicenter study.

OBJECTIVE: Neuromyelitis optica (NMO) is a very severe autoimmune disorder of the central nervous system. It affects young subjects and has a poor prognosis both on a functional and vital level. Therefore, it is imperative to reduce the frequency of relapses. The purpose of this study was to evaluate the clinical and neuroradiological effectiveness of rituximab (RTX) on active forms of NMO. METHODS: We conducted a 2-year open prospective multicenter study that included 32 patients treated with RTX at a dose of 375 mg/m2/week for 1 month. When the number of circulating CD19+ B cells reached 1%, a maintenance therapy was started, consisting of two infusions of 1 g of RTX, administered at a 15-day interval. The primary objective was to reduce the annual relapse rate (ARR), in comparison to that observed in the 2 years before treatment onset. RESULTS: Rituximab administration reduced the ARR from 1.34 to 0.56 (p = 0.0005). The average Expanded Disability Status Scale (EDSS) score significantly improved by 1.1 point, from 5.9 (2-9) to 4.8 (0-9) after 2 years (p = 0.03). Anti-aquaporin-4 antibodies' level predicted treatment failure (p = 0.03). Frequency of Gad+ lesions in spinal cord decreased from 23.3 to 14.2%. RTX treatment did not prevent the death of three patients (treatment failure in two patients and acute myeloid leukemia in a patient previously treated with mitoxantrone). CONCLUSION: Rituximab is clinically effective in active forms of NMO, although few patients are resistant to the treatment.

Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients.

BACKGROUND: Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients. OBJECTIVE: To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation. METHODS: Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively. RESULTS: BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation. CONCLUSION: Typical brain MRI abnormalities are frequent in NMOSD at disease onset.

Neuromyelitis Optica (NMO IgG+) and Genetic Susceptibility, Potential Ethnic Influences.

INTRODUCTION: Neuromyelitis optica (NMO) and Multiple Sclerosis (MS) have been reported in different populations. NMO is more frequent in non-Caucasians, and clinical phenotype differences between populations are likely influenced by genetic susceptibility. In Brazil, it has been reported that NMO patients have a mainly European ancestry background. Like other autoimmune diseases, NMO has a multifactorial origin (i.e., genetics, environmental and infectious factors). Regarding the genetics of NMO, epidemiological findings suggest that a polygenic background has an important role in the development of this type of disease. In this context, various genes have been studied, such as those involved in the synthesis of the T cell beta chain receptor, the VH2-5 gene, myelin basic protein, the CTLA-4 gene, and the interleukin-1 gene. MATERIALS AND METHODS: We performed a study with the main objective of identifying candidate genes involved in the susceptibility to develop NMO in a Mexican population. RESULT: We included 35 patients with an NMO diagnosis according to the Wingerchuk 2006 criteria. The mean age of the patients was 43.3 years old (20-67), and 80 percent of the patients were women. The presence of HLA-DRB1*03 and HLA-DRB1*10 alleles were more frequent in NMO patients than in controls (n=198; p=0.03 and 0.005, respectively). CONCLUSION: There were no differences in the other alleles that have been described in MS subjects, such as HLA-DRB1*04, HLA-DRB1*08 and HLA-DRB1*13. These findings may support the hypothesis that implicated immune-genetics as a key factor in development of this type of disease.

[Comparison of neuromyelitis optica spectra according to AQP4 antibody serostatus in a Mexican referral centre]. / Comparacion de los espectros de neuromielitis optica segun el seroestado del anticuerpo AQP4 en un centro de referencia mexicano.

INTRODUCTION: Recent studies report that patients with neuromyelitis optica (NMO) or seropositive NMO spectra disorders display clinical characteristics that are different from those of patients who are seropositive for the aquaporin-4 (AQP4) antibody. AIM: To analyse the clinical and paraclinical characteristics of patients with NMO according to their serum AQP4 status. PATIENTS AND METHODS: We conducted a retrospective study of 100 patients with NMO who fulfilled the Wingerchuk criteria: 70 were positive for the AQP4 antibody and 30 were seronegative. RESULTS: 70% of the subjects met the criteria for NMO, and 30% met criteria for NMO spectra disorders. The seropositive patients presented greater disability in the scores on the American Spinal Injury Association scale (ASIA) and the Expanded Disability Status Scale (p = 0.034 and 0.004, respectively) compared to seronegatives during the follow-up; in this same group there was greater visual involvement (p = 0.02), a higher number of relapses (p = 0.008) and a greater number of spinal segments involved (p = 0.003). CONCLUSION: This study provides an overview of the clinical and paraclinical characteristics of patients with NMO according to the AQP4 antibody serostatus. Patients who are seropositive for the AQP4 antibody present greater clinical and imaging involvement.

TITLE: Comparacion de los espectros de neuromielitis optica segun el seroestado del anticuerpo AQP4 en un centro de referencia mexicano.Introduccion. Estudios recientes describen que los pacientes con neuromielitis optica (NMO) o trastornos del espectro de NMO seronegativos exhiben caracteristicas clinicas diferentes a los pacientes seropositivos al anticuerpo acuaporina-4 (AQP4). Objetivo. Analizar las caracteristicas clinicas y paraclinicas de pacientes con NMO segun el estado serico del anticuerpo AQP4. Pacientes y metodos. Estudio retrospectivo de 100 pacientes con NMO que cumplian los criterios de Wingerchuk: 70 presentaron positividad al anticuerpo AQP4 y 30 fueron seronegativos. Resultados. Un 70% de los sujetos cumplio los criterios para la NMO, y un 30%, para los trastornos del espectro de NMO. Los pacientes seropositivos presentaron mayor discapacidad en las puntuaciones de la escala de la Asociacion Americana de Lesion de la Medula Espinal (ASIA) y la escala ampliada del estado de discapacidad (p = 0,034 y 0,004, respectivamente) comparados con los seronegativos durante el seguimiento; en este mismo grupo hubo mayor afectacion visual (p = 0,02), mayor numero de recaidas (p = 0,008) y mayor numero de segmentos medulares afectados (p = 0,003). Conclusion. Este estudio proporciona una vision general de las caracteristicas clinicas y paraclinicas de los pacientes con NMO segun el seroestado del anticuerpo AQP4. Los pacientes seropositivos al anticuerpo AQP4 presentan mayor afectacion clinica e imaginologica.

Serological prevalence of celiac disease in Brazilian population of multiple sclerosis, neuromyelitis optica and myelitis.

PURPOSE: Comorbidity of celiac disease with demyelinating diseases of the central nervous system has been reported since the 1960s. The objective of this study was to determine the serological prevalence of celiac disease in the largest series of patients diagnosed with multiple sclerosis, neuromyelitis optica, or myelitis. METHODS: A prevalence study was conducted with patients evaluated at Sarah Network of Rehabilitation Hospitals between March 2012 and September 2013. They were previously diagnosed with multiple sclerosis, neuromyelitis optica, or idiopathic myelitis. The serum levels of antibodies against tissue transglutaminase and endomysium were assessed. RESULTS: Of the 379 patients evaluated, 249 (65.70%) were diagnosed with multiple sclerosis, 37 (9.56%) with neuromyelitis optica, and 96 (24.54%) with idiopathic myelitis. Two patients (0.53%), one with multiple sclerosis and other with myelitis, tested positive for both antibodies. CONCLUSION: Our study do not confirm the relationship between celiac serological antibodies with multiple sclerosis, neuromyelitis optica and inflammatory myelitis of an unknown etiology.

Proteomics comparison of the sera from multiple sclerosis patients and neuromyelitis optica patients.

This study aimed to identify the proteins that are differentially expressed in sera of multiple sclerosis (MS) patients, neuromyelitis optica (NMO) patients, and normal controls by using a two-dimensional gel electrophoresis (2-DE) assay. Serum samples were collected from the 3 groups, and total proteins were isolated and quantified by using the Bradford assay. The 2-DE and silver staining were carried out, and the Image Master 2D Platinum 5.0 software was used to analyze the images. Differentially expressed protein spots were removed from the gel and digested by enzymolysis and high-definition tandem mass spectrometry, and the MASCOT online software was applied to identify the proteins. Three differentially expressed proteins were identified: immunoglobulin (Ig) lambda chain, keratin 83, and haptoglobin (Hp2); the Ig lambda chain was only found in MS patients. The expression of keratin 83 was significantly elevated in the MS group compared to the normal control or NMO groups. The expression of Hp2 in the NMO group was elevated by more than 2-fold compared to the normal control or MS groups. In summary, a variety of proteins were found to be differentially expressed in the serum between MS, NMO, and normal subjects using 2-DE: Ig lambda, Hp2, and keratin 83 were identified as potential diagnostic markers or treatment targets for MS or NMO.

Neuromyelitis optica antibody in Leber hereditary optic neuropathy: case report.

Neuromyelitis optica antibody (or aquaporin-4 antibody) is a well established serum marker associated to high-risk neuromyelitis optica syndrome that presents as an inflammatory demyelinating disease characterized by the occurrence of bilateral and simultaneous optic neuritis without complete visual recovery or it occurs as an isolated episode of transverse myelitis accompanied by longitudinally extensive spinal cord lesions. On the other hand, Leber hereditary optic neuropathy is a primarily hereditary disorder that affects all tissues of the body and its clinical presentation is tissue-specific for the optic nerve and, eventually, it might reach the spinal cord. Overlapping clinical features of neuromyelitis optica and Leber hereditary optic neuropathy may suggest common target organ diseases. The case report described herein emphasizes the coexistence of serum markers of both diseases, and suggests that further investigation of this challenging clinical presentation is warranted to confirm or rule out this association.

Neuromyelitis optica antibody in Leber hereditary optic neuropathy: case report / Anticorpo da neuromielite óptica em neuropatia óptica hereditária de Leber: relato de caso

Neuromyelitis optica antibody (or aquaporin-4 antibody) is a well stablished serum marker associated to high-risk neuromyelitis optica syndrome that presents as an inflammatory demyelinating disease characterized by the occurrence of bilateral and simultaneous optic neuritis without complete visual recovery or it occurs as an isolated episode of transverse myelitis accompanied by longitudinally extensive spinal cord lesions. On the other hand, Leber hereditary optic neuropathy is a primarily hereditary disorder that affects all tissues of the body and its clinical presentation is tissue-specific for the optic nerve and, eventually, it might reach the spinal cord. Overlapping clinical features of neuromyelitis optica and Leber hereditary optic neuropathy may suggest common target organ diseases. The case report described herein emphasizes the coexistence of serum markers of both diseases, and suggests that further investigation of this challenging clinical presentation is warranted to confirm or rule out this association.

Anticorpo da neuromielite óptica (ou anticorpo aquaporina-4) é um marcador sorológico bem estabelecido associado à síndrome de alto risco para neuromielite óptica, doença inflamatória desmielinizante, caracterizada por ocorrência bilateral, simultânea de neurite óptica ou por episódio isolado de mielite transversa com achado de lesões espinais longitudinais extensas. Por outro lado, a neuropatia óptica hereditária de Leber é uma doença primariamente hereditária que afeta todos os tecidos do corpo e sua apresentação clínica envolve o nervo óptico e, eventualmente, a medula espinal. Aspectos clínicos comuns sugerem que neuromielite óptica e neuropatia óptica hereditária de Leber possam atingir os mesmos órgãos. O caso descrito enfatiza a coexistência de marcadores sorológicos das duas doenças e sugere a necessidade de investigação futura desta apresentação clínica atípica para confirmar ou não esta associação.

Aquaporin-4 antibodies are not related to HTLV-1 associated myelopathy.

INTRODUCTION: The seroprevalence of human T-cell leukemia virus type 1 (HTLV-1) is very high among Brazilians (1:200). HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the most common neurological complication of HTLV-1 infection. HAM/TSP can present with an acute/subacute form of longitudinally extensive myelitis, which can be confused with lesions seen in aquaporin-4 antibody (AQP4-Ab) positive neuromyelitis optica spectrum disorders (NMOSD) on MRI. Moreover, clinical attacks in patients with NMOSD have been shown to be preceded by viral infections in around 30% of cases. OBJECTIVE: To evaluate the frequency of AQP4-Ab in patients with HAM/TSP. To evaluate the frequency of HTLV-1 infection in patients with NMOSD. PATIENTS AND METHODS: 23 Brazilian patients with HAM/TSP, 20 asymptomatic HTLV-1+ serostatus patients, and 34 with NMOSD were tested for AQP4-Ab using a standardized recombinant cell based assay. In addition, all patients were tested for HTLV-1 by ELISA and Western blotting. RESULTS: 20/34 NMOSD patients were positive for AQP4-Ab but none of the HAM/TSP patients and none of the asymptomatic HTLV-1 infected individuals. Conversely, all AQP4-Ab-positive NMOSD patients were negative for HTLV-1 antibodies. One patient with HAM/TSP developed optic neuritis in addition to subacute LETM; this patient was AQP4-Ab negative as well. Patients were found to be predominantly female and of African descent both in the NMOSD and in the HAM/TSP group; Osame scale and expanded disability status scale scores did not differ significantly between the two groups. CONCLUSIONS: Our results argue both against a role of antibodies to AQP4 in the pathogenesis of HAM/TSP and against an association between HTLV-1 infection and the development of AQP4-Ab. Moreover, the absence of HTLV-1 in all patients with NMOSD suggests that HTLV-1 is not a common trigger of acute attacks in patients with AQP4-Ab positive NMOSD in populations with high HTLV-1 seroprevalence.

Chitinase effects on immune cell response in neuromyelitis optica and multiple sclerosis.

BACKGROUND: Recent studies conducted in arthritis, asthma, and inflammatory bowel disease suggest that chitinases are important in inflammatory processes and tissue remodeling. OBJECTIVE: To investigate the role of chitinases in multiple sclerosis (MS) and neuromyelitis optica (NMO). METHODS: Levels of chitotriosidase, acid mammalian chitinase (AMCase), and chitinase 3-like-1 (CHI3L1) were measured using ELISA, in cerebrospinal fluid (CSF) and in serum from 24 patients with relapsing remitting (RR) MS, 24 patients with secondary progressive (SP) MS, 12 patients with NMO, 24 patients with other inflammatory neurological diseases (OIND), and 24 healthy controls (HCs). The number of anti-MOG cytokine-secreting cells was studied using ELISPOT. Eotaxins, MCP-1, RANTES, and IL-8 were assessed using ELISA. Cell transmigration was determined using an in vitro blood-brain barrier (BBB) model, in the presence and absence of chitinases. RESULTS: CSF chitinase levels were significantly increased in patients with RRMS and NMO compared with HCs and patients with SPMS and OIND. In contrast, no significant differences were detected in serum chitinase levels between groups. Chitinase CSF levels showed correlation with anti-MOG IL-13-producing cells, and eotaxin levels. In vitro experiments showed macrophage chitinase secretion was significantly increased by IL-13, but not by IL-5, IL-6, IL-12, or IFN-γ. Moreover, chitinases enhanced IL-8, RANTES, MCP-1, and eotaxin production, increasing migratory capacity in eosinophils, T cells, and macrophages across an in vitro BBB model. CONCLUSIONS: Chitinases increased in the CSF from patients with NMO in response to IL-13. These enhanced levels could contribute to central nervous system inflammation by increasing immune cell migration across the BBB.

Differential regulation of IgG-NMO autoantibodies on S100Beta protein and disability in relapsing neuromyelitis optica.

Neuromyelitis optica (NMO), an uncommon central nervous system (CNS) demyelinating disease, produces transverse myelitis and severe optic neuritis. IgG-NMO autoantibody, a specific immunoglobulin binding aquaporin-4 water channel protein, confirms that NMO is a different entity to multiple sclerosis. Parallel to cytokine down-regulations found in serum of relapsing-NMO (rNMO) patients, it has been reported that IgG-NMO may also confer a worse course of the disease in r-NMO Caribbean patients. In this study, we were interested in exploring the influence of IgG-NMO autoantibody on S100beta levels and clinical parameters from serum of r-NMO patients. Serum samples from 24 rNMO patients and 10 controls were evaluated. The reduction of S100beta observed in r-NMO patients was not significant compared to controls; and no differences were present regarding IgG-NMO immunoreactivity. At the same time, a significant correlation was also observed between IgG-NMO autoantibody serum detection and EDSS (Expanded Disability Status Scale) in rNMO. These results corroborate a differential regulation of IgG-NMO autoantibodies on the S100beta glial marker and on the disability present in rNMO patients.

Immune system markers of neuroinflammation in patients with clinical diagnose of neuromyelitis optica.

Neuromyelitis optica (NMO) is an inflammatory, demyelinating disease of the central nervous system characterized by the association of a serious myelitis and unilateral or bilateral optic neuritis. The present study aimed to analyze the immunological parameters of NMO patients with diagnosis established based on Wingerchuck et al. (1999) criteria. Production of IgG and IgA antibodies to antigens of MBP, PLP 95-116, MOG 92-106, and the cytokines interleukin-4 (IL-4) and interferon-gamma (INF-gamma) were assessed by Elisa assay. The cohort was formed by 28 NMO patients and a matched healthy control group. NMO patients had significant high levels of IgG to MOG (p<0.0001), PLP (p=0.0002) and MBP (p<0.0001), and solely IgA to MBP (p<0.0001). INF-gamma (p=0.61) levels were similar to healthy controls. Increased production of IL-4 (p=0.0084) indicates an important role for this cytokine in the activation of Th2 regulatory cells and of the IgA producers B lymphocyte indicating activation of humoral immunity.

Immune system markers of neuroinflammation in patients with clinical diagnose of neuromyelitis optica / Marcadores imunológicos em pacientes com diagnóstico de neuromielite óptica

Neuromyelitis optica (NMO) is an inflammatory, demyelinating disease of the central nervous system characterized by the association of a serious myelitis and unilateral or bilateral optic neuritis. The present study aimed to analyze the immunological parameters of NMO patients with diagnosis established based on Wingerchuck et al. (1999) criteria. Production of IgG and IgA antibodies to antigens of MBP, PLP 95-116, MOG 92-106, and the cytokines interleukin-4 (IL-4) and interferon-γ (INF-γ) were assessed by Elisa assay. The cohort was formed by 28 NMO patients and a matched healthy control group. NMO patients had significant high levels of IgG to MOG (p<0.0001), PLP (p=0.0002) and MBP (p<0.0001), and solely IgA to MBP (p<0.0001). INF-γ (p=0.61) levels were similar to healthy controls. Increased production of IL-4 (p=0.0084) indicates an important role for this cytokine in the activation of Th2 regulatory cells and of the IgA producers B lymphocyte indicating activation of humoral immunity.

A neuromielite óptica (NMO) é doença inflamatória do sistema nervoso central, caracterizada por mielite aguda ou subaguda grave e neurite óptica unilateral ou bilateral. Este estudo objetiva analisar parâmetros imunológicos de pacientes com critérios de Wingerchuck et al. (1999) para NMO. O método de ELISA avaliou a produção de IgG e IgA para antígenos da proteína básica da mielina (MBP), o proteolipídeo (PLP) 95-116, a glicoproteina associada ao oligodendrócito (MOG) 92-106 e as citocinas interleucina-4 (IL-4) e interferon-gama (INF-γ). Foram incluνdos 28 pacientes com NMO pareados com controles saudáveis. Pacientes com NMO apresentaram níveis significativamente elevados de imunoglobulinas reativas dos isotipos IgG para MOG (p<0,0001), PLP (p=0,0002) e MBP (p<0,0001) e IgA somente para MBP (p<0,0001). Os níveis de INF-γ (p=0,61) foram semelhantes aos controles. A produção elevada de IL-4 (p=0,0084) indica papel importante na ativação de células regulatórias Th2 e linfócitos B produtores de IgA e da ativação da imunidade humoral.