Serum Reactive Antibodies against the N-Methyl-D-Aspartate Receptor NR2 Subunit-Could They Act as Potential Biomarkers?

Synaptic dysfunction and disrupted communication between neuronal and glial cells play an essential role in the underlying mechanisms of multiple sclerosis (MS). Earlier studies have revealed the importance of glutamate receptors, particularly the N-methyl-D-aspartate (NMDA) receptor, in excitotoxicity, leading to abnormal synaptic transmission and damage of neurons. Our study aimed to determine whether antibodies to the NR2 subunit of NMDAR are detected in MS patients and evaluate the correlation between antibody presence and clinical outcome. Furthermore, our focus extended to examine a possible link between NR2 reactivity and anti-coagulant antibody levels as pro-inflammatory molecules associated with MS. A cross-sectional study was carried out, including 95 patients with MS and 61 age- and gender-matched healthy controls (HCs). The enzyme-linked immunosorbent assay was used to detect anti-NR2 antibodies in serum samples of participants along with IgG antibodies against factor (F)VIIa, thrombin, prothrombin, FXa, and plasmin. According to our results, significantly elevated levels of anti-NR2 antibodies were detected in MS patients compared to HCs (p < 0.05), and this holds true when we compared the Relapsing-Remitting MS course with HCs (p < 0.05). A monotonically increasing correlation was found between NR2 seropositivity and advanced disability (rs = 0.30; p < 0.01), anti-NR2 antibodies and disease worsening (rs = 0.24; p < 0.05), as well as between antibody activity against NR2 and thrombin (rs = 0.33; p < 0.01). The presence of anti-NR2 antibodies in MS patients was less associated with anti-plasmin IgG antibodies [OR:0.96 (95%CI: 0.92-0.99); p < 0.05]; however, such an association was not demonstrated when analyzing only RRMS patients. In view of our findings, NR2-reactive antibodies may play, paving the way for further research into their potential as biomarkers and therapeutic targets in MS.

A Comparison of Two Analytical Approaches for the Quantification of Neurofilament Light Chain, a Biomarker of Axonal Damage in Multiple Sclerosis.

Neurofilament light chain (NfL), is a neuron-specific cytoskeletal protein detected in extracellular fluid following axonal damage. Extensive research has focused on NfL quantification in CSF, establishing it as a prognostic biomarker of disability progression in Multiple Sclerosis (MS). Our study used a new commercially available Enzyme-Linked Immunosorbent Assay (ELISA) kit and Single Molecular Array (Simoa) advanced technology to assess serum NfL levels in MS patients and Healthy Controls (HC). Verifying the most accurate, cost-effective methodology will benefit its application in clinical settings. Blood samples were collected from 54 MS patients and 30 HC. Protocols accompanying the kits were followed. The ELISA thershold was set as 3 S.D. above the mean of the HC. For Simoa, the Z-score calculation created by Jens Kuhle's group was applied (with permission). Samples exceeding the threshold or z-score ≥1.5 indicated subclinical disease activity. To our knowledge, this is the first study to find strong-positive correlation between ELISA and Simoa for the quantification of NfL in serum (r = 0.919). Despite the strong correlation, Simoa has better analytical sensitivity and can detect small changes in samples making it valuable in clinical settings. Further research is required to evaluate whether serum NfL quantification using ELISA could be utilized to predict disability progression.

Changes in regulation of human monocyte proteins in response to IgG from patients with antiphospholipid syndrome.

The effects of immunoglobulin G (IgG) from patients with the antiphospholipid syndrome (APS) upon monocyte activation have not been fully characterized. We carried out a comprehensive proteomic analysis of human monocytes treated with IgG from patients with different manifestations of the APS. Using 2-dimensional differential gel electrophoresis (2D DiGE), 4 of the most significantly regulated proteins (vimentin [VIM], zinc finger CCH domain-containing protein 18, CAP Gly domain-containing linker protein 2, and myeloperoxidase) were differentially regulated in monocytes treated with thrombotic or obstetric APS IgG, compared with healthy control (HC) IgG. These findings were confirmed by comparing monocytes isolated from APS patients and HC. Anti-VIM antibodies (AVAs) were significantly increased in 11 of 27 patients (40.7%) with APS. VIM expression on HC monocytes was stimulated more strongly by APS IgG from patients with higher-avidity serum AVA. We further characterized the proteome of thrombotic APS IgG-treated monocytes using a label-free proteomics technique. Of 12 proteins identified with the most confidence, 2 overlapped with 2D DiGE and many possessed immune response, cytoskeletal, coagulation, and signal transduction functions which are all relevant to APS and may therefore provide potential new therapeutic targets of this disease.

List2Net: Linking multiple lists of biological data in a network context.

Motivation: A common task in scientific research is the comparison of lists or sets of diverse biological entities such as biomolecules, ontologies, sequences and expression profiles. Such comparisons rely, one way or another, on calculating a measure of similarity either by means of vector correlation metrics, set operations such as union and intersection, or specific measures to capture, for example, sequence homology. Subsequently, depending on the data type, the results are often visualized using heatmaps, Venn, Euler, or Alluvial diagrams. While most of the abovementioned representations offer simplicity and interpretability, their effectiveness holds only for a limited number of lists and specific data types. Conversely, network representations provide a more versatile approach where data lists are viewed as interconnected nodes, with edges representing pairwise commonality, correlation, or any other similarity metric. Networks can represent an arbitrary number of lists of any data type, offering a holistic perspective and most importantly, enabling analytics for characterizing and discovering novel insights in terms of centralities, clusters and motifs that can exist in such networks. While several tools that implement the translation of lists to the various commonly used diagrams, such as Venn and Euler, have been developed, a similar tool that can parse, analyze the commonalities and generate networks from an arbitrary number of lists of the same or heterogenous content does not exist. Results: To address this gap, we introduce List2Net, a web-based tool that can rapidly process and represent lists in a network context, either in a single-layer or multi-layer mode, facilitating network analysis on multi-source/multi-layer data. Specifically, List2Net can seamlessly handle lists encompassing a wide variety of biological data types, such as named entities or ontologies (e.g., lists containing gene symbols), sequences (e.g., protein/peptide sequences), and numeric data types (e.g., omics-based expression or abundance profiles). Once the data is imported, the tool then (i) calculates the commonalities or correlations (edges) between the lists (nodes) of interest, (ii) generates and renders the network for visualization and analysis and (iii) provides a range of exporting options, including vector, raster format visualization but also the calculated edge lists and metrics in tabular format for further analysis in other tools. List2Net is a fast, lightweight, yet informative application that provides network-based holistic insights into the conditions represented by the lists of interest (e.g., disease-to-disease, gene-to-phenotype, drug-to-disease, etc.). As a case study, we demonstrate the utility of this tool applied on publicly available datasets related to Multiple Sclerosis (MS). Using the tool, we showcase the translation of various ontologies characterizing this specific condition on disease-to-disease subnetworks of neurodegenerative, autoimmune and infectious diseases generated from various levels of information such as genetic variation, genes, proteins, metabolites and phenotypic terms.

SARS-CoV-2-specific antibody responses following BNT162b2 vaccination in individuals with multiple sclerosis receiving different disease-modifying treatments.

Introduction: The study aims to evaluate the concentration of IgG antibodies against the receptor-binding domain of the SARS-CoV-2 spike1 protein (S1RBD) in BNT162b2- vaccinated relapsing-remitting multiple sclerosis (RRMS) individuals receiving disease-modifying treatments (DMTs). Methods: Serum from 126 RRMS volunteers was collected 3 months after the administration of the second dose of the Pfizer-BioNTech BNT162b2 vaccine. Additional samples were analyzed after the administration of the booster dose in fingolimod- treated MS. Anti-S1RBD IgG antibody concentrations were quantified using the ABBOTT SARS-CoV-2 IgG II Quant assay. Results: Anti-S1RBD IgG antibody concentrations in RRMS individuals receiving natalizumab, interferons, teriflunomide, and dimethyl fumarate showed no significant difference to those in healthy controls. However, fingolimod-treated MS individuals showed a marked inability to produce SARS-CoV-2- specific antibodies (p < 0.0001). Furthermore, a booster dose was not able to elicit the production of IgG antibodies in a large portion of matched individuals. Discussion: A possible explanation for the altered immune response in fingolimod- treated MS individuals could be due to the medication inhibiting the circulation of lymphocytes, and possibly in turn inhibiting antibody production. Overall, patients on DMTs are generally of no disadvantage toward mounting an immune response against the vaccine. Nevertheless, further studies require evaluating non-humoral immunity against SARS-CoV-2 following vaccination, as well as the suitability of such vaccinations on patients treated with fingolimod.

A Preclinical Investigation on the Role of IgG Antibodies against Coagulant Components in Multiple Sclerosis.

The coagulation-inflammation interplay has recently been identified as a critical risk factor in the early onset of multiple sclerosis (MS), and antibodies against coagulation components have been recognized as contributing factors to thrombotic and inflammatory signaling pathways in diseases with overlapping symptoms to MS, paving the way for further research into their effects on MS pathology. The current study aimed to enlighten the role of IgG antibodies against coagulation components by performing a preclinical study, analyzing the astrocytic activation by purified IgG antibodies derived from 15 MS patients, and assessing their possible pro-inflammatory effects using a bead-based multiplexed immunoassay system. The results were compared with those obtained following astrocyte treatment with samples from 14 age- and gender-matched healthy donors, negative for IgG antibody presence. Serum samples collected from 167 MS patients and 40 age- and gender-matched controls were also analyzed for pro- and anti-inflammatory factors. According to our results, astrocytic activation in response to IgG treatment caused an upregulation of various pro-inflammatory factors, including cytokines, chemokines, and interleukins. Conversely, in serum samples from patients and controls, the pro-inflammatory factors did not differ significantly; medication may lower the levels in patients. Our findings suggest that antibodies may function as effectors in neuroinflammation and serve as targets for new treatments that eventually benefit novel therapeutic approaches.

Interactions of human monoclonal and polyclonal antiphospholipid antibodies with serine proteases involved in hemostasis.

OBJECTIVE: To characterize the interaction between procoagulant and/or anticoagulant serine proteases and human monoclonal IgG antiphospholipid antibodies (aPL) and polyclonal IgG derived from patients with the antiphospholipid syndrome (APS). METHODS: Five human monoclonal IgG with small differences in their sequences were tested for binding to protein C, activated protein C, plasmin, factor VIIa (FVIIa), FIX, FIXa, and FXII. Serum levels of antithrombin and anti-activated protein C were compared in 32 patients with APS, 29 patients with systemic lupus erythematosus (SLE), and 22 healthy controls. Purified polyclonal IgG derived from APS patients with elevated levels of serum antithrombin antibodies was also tested for its functional effects on thrombin and antithrombin activity. RESULTS: Studies of monoclonal antibodies showed that sequence changes in human aPL are important in determining their ability to bind procoagulant and anticoagulant/fibrinolytic serine proteases. Mean IgG antithrombin levels were significantly elevated in patients with APS and in SLE patients with aPL but no APS (SLE/aPL+) compared to healthy controls, but anti-activated protein C levels were not increased in these patients. Moreover, IgG purified from patients with APS displayed higher avidity for thrombin and significantly inhibited antithrombin inactivation of thrombin compared with IgG from SLE/aPL+ patients. CONCLUSION: High-avidity antithrombin antibodies, which prevent antithrombin inactivation of thrombin, distinguish patients with APS from SLE/aPL+ patients, and thus may contribute to the pathogenesis of vascular thrombosis in APS.

Effects of polyclonal IgG derived from patients with different clinical types of the antiphospholipid syndrome on monocyte signaling pathways.

A major mechanism of hypercoagulability in the antiphospholipid syndrome (APS) is antiphospholipid Ab-mediated upregulation of tissue factor (TF) on monocytes via activation of TLRs, p38 MAPK, and NF-kappaB pathways. We examined whether monocyte signaling pathways are differentially activated by IgG from patients with vascular thrombosis (VT) alone compared with IgG from patients with pregnancy morbidity (PM) alone. We purified IgG from 49 subjects. A human monocyte cell line and ex vivo healthy monocytes were treated with 100 microg/ml IgG for 6 h, and cell extracts were examined by immunoblot using Abs to p38 MAPK and NF-kappaB. To further investigate intracellular signaling pathways induced by these IgGs, specific inhibitors of p38 MAPK, NF-kappaB, TLR4, and TLR2 were used to determine their effect on TF activity. Only IgG from patients with VT but no PM (VT+/PM-) caused phosphorylation of NF-kappaBand p38 MAPK and upregulation of TF activity in monocytes. These effects were not seen with IgG from patients with PM alone (VT-/PM+), anti-phospholipid Ab-positive patients without APS, or healthy controls. TF upregulation caused by the VT+/PM- samples was reduced by inhibitors of p38 MAPK, NF-kappaB, and TLR4. The effects of VT+/PM- IgG on signaling and TF upregulation were concentrated in the fraction that bound beta-2-glycoprotein I. Our findings demonstrate that IgGs from patients with diverse clinical manifestations of APS have differential effects upon phosphorylation of NF-kappaB and p38 MAPK and TF activity that may be mediated by differential activation of TLR4.

Evaluation of S1RBD-Specific IgG Antibody Responses following COVID-19 Vaccination in Healthcare Professionals in Cyprus: A Comparative Look between the Vaccines of Pfizer-BioNTech and AstraZeneca.

There is an ongoing effort to report data on SARS-CoV-2 antibodies in different individuals. Ninety-seven healthcare workers were enrolled in this study (Pfizer's BNT162b2, n = 52; and AstraZeneca's ChAdOx1-S, n = 45) and S1RBD-specific IgG antibodies were analyzed over time. Both vaccines induced S1RBD-specific antibodies after the second dose. A significant increase in S1RBD-specific IgG median levels 3 weeks following the second dose was detected (BNT162b2, 118.0 BAU/mL to 2018.0 BAU/mL; ChAdOx1-S, 38.1 BAU/mL to 182.1 BAU/mL). At 3 months post the second dose, a significant decrease in S1RBD-specific IgG median levels was also evident (BNT162b2, 415.6 BAU/mL, ChAdOx1-S, 84.7 BAU/mL). The elimination rate of these antibodies was faster in BNT162b2- rather than ChAdOx1-S- vaccinated individuals. A booster dose induced a significant increase in the S1RBD-specific IgG median levels (BNT162b2, 1823.0 BAU/mL; ChAdOx1-S, 656.8 BAU/mL). This study is the first of its kind to characterize S1RBD-specific IgG antibody responses in vaccinated healthcare workers in Cyprus. While the positivity for S1RBD-specific antibodies was maintained 3 months after the second vaccine dose, the level of these antibodies waned over the same period, indicating the importance of a booster vaccination. The results herein could complement the public health policies regarding the immunization schedule for COVID-19.

Antibodies to blood coagulation components are implicated in patients with multiple sclerosis.

BACKGROUND: The strong link between innate immunity and thrombosis/coagulation has recently been investigated in the light of antibodies directed against serine proteases of the coagulation pathway. The antibodies have been proposed as contributing factors to venous thromboembolism development and as key molecules in the initiation of signaling inflammatory pathways in neuroinflammatory diseases. Preliminary studies of Multiple Sclerosis (MS) progression characteristics with the reactivity of antibodies against coagulant components are limited. Considering the development of thrombosis at the early onset of MS, our study aimed to detect antibodies against coagulant components in MS and evaluate their possible association with the clinical profile of the disease. METHOD: A cross-sectional study was carried out to identify antibodies to factor(F)VIIa, thrombin, prothrombin, FXa, FXII, plasmin, and protein C in serum samples from 167 patients with MS and 40 healthy controls using the enzyme-linked immunosorbent assay. Statistical analysis was performed for the evaluation of the data. RESULTS: The analysis revealed a significantly higher prevalence of IgG in MS patients (n = 72, 43%) compared to HCs (n = 8, 20%, p < 0.01). Specifically, elevated anti-FVIIa (n = 19, 11.4%, mean activity p < 0.0001), anti-FXII (n = 12, 7.2%, mean activity p < 0.001) and anti-plasmin (n = 20, 12%, mean activity p < 0.01) levels were observed in patients compared to controls. Additionally, the highest scores of clinical characteristics like the expanded disability status scale and MS severity score were linked with IgG seropositivity against thrombin, whilst anti-FXII levels corresponded with the lowest disease progression. CONCLUSION: The findings of our study illustrate the presence of antibodies against serine proteases of the coagulation cascade in MS and demonstrate the association of antibody activity with disease progression. In particular, thrombin IgG seropositivity was demonstrated to be associated with worse outcomes and a severe disease phenotype. These observations suggest the implication of antibodies in patient monitoring and prognosis, and further evaluation may elucidate inflammatory cascades in which antibodies act as key mediators.

SARS CoV- 2 vaccination induces antibodies against cardiolipin.

OBJECTIVE: Cases of thrombosis have been reported after administration of SARS-CoV-2 vaccines, with controversial results relating to Oxford-AstraZeneca's ChAdOx1-S. Despite such cases being rare, they still raised concerns for their involvement in coagulopathies. Anti-cardiolipin (aCL) IgG antibodies have been linked to venous and arterial thrombosis. The aim was to evaluate the concentration of aCL IgG antibodies in vaccinated and COVID-19 positive individuals using indirect ELISA and commercial sourced calibrators. RESULTS: The concentration of aCL IgG antibodies was measured in the serum of COVID-19 positive (n = 37), ChAdOx1-S vaccinated (n = 37) and BioNTech Pfizer BNT162b2 vaccinated (n = 42) individuals. Samples from COVID-19 negative, unvaccinated individuals (n = 41) served as controls. The highest percentage of positivity was in the COVID-19 positive group (18.9%). Concerning vaccination, BNT162b2 had the highest percentage of positivity (11.9%) (p = 0.0037). Additionally, aCL concentrations were evaluated at different time points in both vaccinated groups (before, 3 weeks after and 3 months after the second dose). A significant difference in the levels of aCL IgG antibodies over time (p = 0.0391) was observed only in ChAdOx1-S individuals. Our study concluded that levels of aCL, after vaccination with either of the vaccines or following SARS-CoV-2 infection, were not clinically pathogenic for the risk of thrombosis.

Genetic Markers for Thrombophilia and Cardiovascular Disease Associated with Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system (CNS) with an unknown etiology, although genetic, epigenetic, and environmental factors are thought to play a role. Recently, coagulation components have been shown to provide immunomodulatory and pro-inflammatory effects in the CNS, leading to neuroinflammation and neurodegeneration. The current study aimed to determine whether patients with MS exhibited an overrepresentation of polymorphisms implicated in the coagulation and whether such polymorphisms are associated with advanced disability and disease progression. The cardiovascular disease (CVD) strip assay was applied to 48 MS patients and 25 controls to analyze 11 genetic polymorphisms associated with thrombosis and CVD. According to our results, FXIIIVal34Leu heterozygosity was less frequent (OR: 0.35 (95% CI: 0.12-0.99); p = 0.04), whereas PAI-1 5G/5G homozygosity was more frequent in MS (OR: 6.33 (95% CI: 1.32-30.24); p = 0.016). In addition, carriers of the HPA-1a/1b were likely to have advanced disability (OR: 1.47 (95% CI: 1.03-2.18); p = 0.03) and disease worsening (OR: 1.42 (95% CI: 1.05-2.01); p = 0.02). The results of a sex-based analysis revealed that male HPA-1a/1b carriers were associated with advanced disability (OR: 3.04 (95% CI: 1.22-19.54); p = 0.01), whereas female carriers had an increased likelihood of disease worsening (OR: 1.56 (95% CI: 1.04-2.61); p = 0.03). Our findings suggest that MS may be linked to thrombophilia-related polymorphisms, which warrants further investigation.

Antibodies to apolipoprotein A-I, high-density lipoprotein, and C-reactive protein are associated with disease activity in patients with systemic lupus erythematosus.

OBJECTIVE: Inflammatory disease activity in patients with systemic lupus erythematosus (SLE) may affect the development of atherosclerosis, contributing to their increased risk of cardiovascular disease (CVD). This process may be mediated by anti-apolipoprotein A-I (anti-Apo A-I), anti-high-density lipoprotein (anti-HDL), and anti-C-reactive protein (anti-CRP) autoantibodies. We undertook this study to examine whether levels of these antibodies rise in association with increased SLE disease activity. METHODS: IgG anti-Apo A-I, anti-HDL, and anti-CRP levels were measured in serum from the following groups: 39 patients with persistently high disease activity (British Isles Lupus Assessment Group [BILAG] A or B score) over the previous 2 years, 42 patients with persistently low disease activity (no BILAG A or B scores) over the previous 2 years, 34 healthy controls, 25 individual patients from whom paired samples (at time of disease flare and quiescence) were obtained and compared, 16 patients with newly diagnosed lupus nephritis from whom multiple samples were obtained and who were followed up prospectively for up to 2 years, and 24 patients with SLE who had experienced CVD events. RESULTS: Serum levels of IgG anti-Apo A-I, anti-HDL, and anti-CRP were higher in patients with SLE than in controls. Anti-Apo A-I and anti-HDL levels, but not anti-CRP levels, were higher in patients with persistently high disease activity than in those with low disease activity. Mean levels of the 3 autoantibodies in patients who had experienced CVD events lay between the mean levels in the high and low disease activity groups. Only levels of anti-Apo A-I were significantly higher in samples obtained from individual patients during disease flares than in samples obtained during disease quiescence. In the lupus nephritis patients, anti-Apo A-I and anti-HDL levels correlated with serum levels of high avidity IgG anti-double-stranded DNA. CONCLUSION: Persistent disease activity is associated with a significant increase in IgG anti-Apo A-I and anti-HDL in patients with SLE.

Thrombin binding predicts the effects of sequence changes in a human monoclonal antiphospholipid antibody on its in vivo biologic actions.

The mechanisms by which antiphospholipid Abs (aPL) cause thrombosis are not fully understood. It is clear that binding to a number of phospholipid-associated Ags is important but it is difficult to identify which Ag-binding properties are most closely linked to the ability to cause biologic effects such as promotion of thrombosis and activation of endothelial cells. We have previously used an in vitro expression system to produce a panel of human monoclonal IgG molecules between which we engineered small differences in sequence leading to significant well-defined changes in binding properties. In this study, we assess the properties of five of these IgG molecules in assays of biologic function in vitro and in vivo. The i.p. injection of these IgG into mice subjected to a femoral vein pinch stimulus showed that only those IgG that showed strong binding to thrombin promoted in vivo venous thrombosis and leukocyte adherence. However, this finding did not hold true for the effects of these IgG on activation of cultured endothelial cells in vitro, where there was a less clear relationship between binding properties and biologic effects.

Characterization of IgG Antibody Response against SARS-CoV-2 (COVID-19) in the Cypriot Population.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has hit its second year and continues to damage lives and livelihoods across the globe. There continues to be a global effort to present serological data on SARS-CoV-2 antibodies in different individuals. As such, this study aimed to characterize the seroprevalence of SARS-CoV-2 antibodies in the Cypriot population for the first time since the pandemic started. Our results show that a majority of people infected with SARS-CoV-2 developed IgG antibodies against the virus, whether anti-NP, anti-S1RBD, or both, at least 20 days after their infection. Additionally, the percentage of people with at least one antibody against SARS-CoV-2 in the group of volunteers deemed SARS-CoV-2 negative via RT-PCR or who remain untested/undetermined (14.43%) is comparable to other reported percentages worldwide, ranging anywhere from 0.2% to 24%. We postulate that these percentages reflect the underreporting of true infections in the population, and also show the steady increase of herd immunity. Additionally, we showed a significantly marked decrease in anti-NP IgG antibodies in contrast to relatively stable levels of anti-S1RBD IgG antibodies in previously infected individuals across time.

The expression profile of virus-recognizing toll-like receptors in natural killer cells of Cypriot multiple sclerosis patients.

OBJECTIVE: The exact aetiology of multiple sclerosis (MS) remains elusive, although several environmental and genetic risk factors have been implicated to varying degrees. Among the environmental risk factors, viral infections have been suggested as strong candidates contributing to MS pathology/progression. Viral recognition and control are largely tasked to the NK cells via TLR recognition and various cytotoxic and immunoregulatory functions. Additionally, the complex roles of different TLRs in MS pathology are highlighted in multiple, often contradictory, studies. The present work aims to analyse the TLR expression profile of NK cells isolated from MS patients. Highly purified CD56+CD3- NK cells isolated from peripheral blood of MS patients (n = 19) and healthy controls (n = 20) were analysed via flow cytometry for their expression of viral antigen-recognizing TLRs (TLR2, TLR3, TLR7, and TLR9). RESULTS: No difference was noted in TLR expression between MS patients and healthy controls. These results aim to supplement previous findings which study expressional or functional differences in TLRs present in various subsets of the immune system in MS, thus aiding in a better understanding of MS as a complex multifaceted disease.

Mechanisms of activation induced by antiphospholipid antibodies in multiple sclerosis: Potential biomarkers of disease?

Multiple sclerosis (MS) is a chronic, multifactorial, inflammatory disease of the central nervous system where demyelination leads to neurodegeneration and disability. The pathogenesis of MS is incompletely understood, with prevalence of antiphospholipid antibodies (aPL) speculated to contribute to MS pathogenesis. In fact, MS shares common clinical features with the Antiphospholipid Syndrome (APS) such as venous thromboembolism. Consequently, the presence of aPL which are associated with blood clot formation in the APS need to be further investigated for a possible pro-coagulant role in the development of thrombosis in MS. The effects of IgG aPL from patients with MS upon astrocyte activation has never been characterized. We purified IgG from 30 subjects. A human astrocytic cell line was treated with 100 µg/ml IgG for 1 h, and cell extracts were examined by immunoblot using antibodies to p38 MAPK and NFκB to further examine intracellular signaling pathways induced by these IgGs. Only IgG from patients who are positive for aPL caused phosphorylation of p38 MAPK and NFκB in astrocytes. These effects were not seen with IgG from patients with MS but with no aPL or healthy controls. Understanding the intracellular mechanism of aPL-mediated astrocyte activation may help to establish new therapeutic approaches, such as selective inhibition of the mitogen-activated protein kinases, to control MS activity or possible thrombotic states.

Complete sequence analysis of human toll-like receptor 3 gene in natural killer cells of multiple sclerosis patients.

BACKGROUND: Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS) where both environmental and genetic risk factors play a role. Among the environmental risk factors, EBV and HSV infections have been suggested as strong candidates contributing to MS pathology/progression. Viral recognition and control is largely tasked to the NK cells via TLR recognition and various cytotoxic and immunoregulatory functions. The present work aimed to characterize NK cells isolated from MS patients for genetic polymorphisms in the gene encoding for TLR3, as TLR3 in NK cells is important in herpesvirus recognition. METHODS: Highly purified NK cells isolated from peripheral blood of MS patients (n = 27) and healthy controls (n = 30) were used to sequence all five exons of the TLR3 gene using sanger sequencing. Alignment of the obtained sequences with the wild-type TLR3 sequence was used to identify genetic polymorphisms within the TLR3 gene. RESULTS: The alignment identified multiple substitution mutations across the five exons of the TLR3 gene (rs116729895, rs3775296, rs377529, rs3775290, rs3775291, rs376735334 and rs73873710). A significant difference was observed in the allele distribution of rs3775291 (Leu412Phe) between MS patients and HC, whereby the minor allele was detected in 38.9% of MS patients versus 11% of HC (Fisher's exact test, p = 0.021). CONCLUSION: There appears to be a possible association between the TLR3 missense mutation rs3775291 and multiple sclerosis, which might be attributed to changes in the TLR3 functional properties.

Evaluation of Epstein-Barr virus-specific antibodies in Cypriot multiple sclerosis patients.

Multiple Sclerosis (MS) is a chronic, demyelinating, inflammatory disease of the central nervous system (CNS) with a strong autoimmune component. Several genetic and environmental factors have been suggested to contribute in MS. The Epstein-Barr virus (EBV) is one pathogenic candidate proposed to be involved in the onset of MS and/or induction of subsequent exacerbations. The possible involvement of EBV in MS is highlighted by a number of national epidemiological studies showing a higher percentage of EBV seropositivity. This study aims to evaluate for the first time the seroprevalence of EBV in Cypriot MS patients. The serum of 133 MS patients and 101 healthy controls (HCs) was used to determine the positivity index of the EBV nuclear antigen-1 (EBNA-1) IgG, viral capsid antigen (VCA) IgG, and early antigen-D (EA-D) IgG, using ELISA. All MS patients were seropositive for both EBNA-1 IgG and VCA IgG as compared to 94.1% (Fisher's exact test, p = 0.0059) and 93.1% (Fisher's exact test, p = 0.0025) of HCs respectively. Furthermore, the positivity indexes of both antibodies were significantly higher in MS patients. There was no significant difference in the presence/absence of EA-D IgG between the two groups nor in the corresponding P.I. levels. The results obtained, revealing higher seropositivity of EBNA-1 IgG and VCA IgG in MS patients, seem to concur with previous findings of studies in other countries, thereby further asserting the theory of EBV involvement in MS.

The possible role of an autoimmune mechanism in the etiopathogenesis of Parkinson's disease.

The clinical diagnosis of Parkinson's disease (PD) is established through clinical signs such as bradykinesia, rigidity, and resting tremor. Recently, immune system involvement has been implicated as a major pathogenic factor in the onset and progression of PD. We examine the presence of autoantibodies against phosphatidylserine (PS), cardiolipin (CL) and dsDNA in 45 PD patients and 38 healthy controls and provide evidence to the possible connection to oxidative stress. We report higher frequency of IgG anti-PS and anti-dsDNA in PD patients (24.4% and 15.6%), compared to controls (2.6% in both cases, p < 0.05). Moreover, the presence of these autoantibodies is not analogous with increased levels of oxidative stress in PD. A great need exists for improved understanding of the pathogenesis and identification of relevant biomarkers and future studies in clarifying the role of autoantibodies in PD are required to address its role as a potential risk factor.