Cytokines and chemokines expression in serum of patients with neuromyelitis optica

Associations of the circulating levels of cytokines with risk of ankylosing spondylitis: a Mendelian randomization study

Background

Observational studies have shown that changes in circulating cytokine/growth factor levels occur throughout the initiation and progression of ankylosing spondylitis (AS), yet whether they are etiologic or downstream effects remains unclear. In this study, we performed a summarized-level bidirectional Mendelian randomization (MR) analysis to shed light on the causal relationship between the two.

Methods

Genetic instrumental-variables (IVs) associated with circulating cytokine/growth factor levels were derived from a genome-wide association study (GWAS) of 8,293 European individuals, whereas summary data for the AS were obtained from a FinnGen GWAS of 166,144 participants. We used the inverse-variance-weighted (IVW) method as the main analysis for causal inference. Furthermore, several sensitivity analyses (MR-Egger, weighted median, MR-PRESSO and Cochran's Q test) were utilized to examine the robustness of the results. Finally, reverse MR analysis was performed to assess reverse causality between AS and circulating cytokine/growth factor levels.

Results

After Bonferroni correction, circulating levels of Cutaneous T-cell attracting (CTACK) and Monocyte specific chemokine 3 (MCP-3) were positively associated with a higher risk of AS (odds ratio [OR]: 1.224, 95% confidence interval [95% Cl]: 1.022 ~ 1.468, P = 0.028; OR: 1.250, 95% Cl: 1.016 ~ 1.539, P = 0.035). In addition, elevated circulating levels of Basic fibroblast growth factor (FGF-basic), Granulocyte colony-stimulating factor (G-CSF) and MCP-3 was considered a consequence of AS disease (β = 0.023, P = 0.017; β = 0.017, P = 0.025; β = 0.053, P = 0.025). The results of the sensitivity analysis were generally consistent.

Conclusion

The present study supplies genetic evidence for the relationship between circulating cytokine levels and AS. Targeted interventions of specific cytokines may help to reduce the risk of AS initiation and progression.

NMOSD IgG Impact Retinal Cells in Murine Retinal Explants

Neuromyelitis optica spectrum disorders (NMOSD) are chronic inflammatory diseases of the central nervous system, characterized by autoantibodies against aquaporin-4. The symptoms primarily involve severe optic neuritis and longitudinally extensive transverse myelitis. Although the disease progression is typically relapse-dependent, recent studies revealed retinal neuroaxonal degeneration unrelated to relapse activity, potentially due to anti-aquaporin-4-positive antibodies interacting with retinal glial cells such as Müller cells. In this exploratory study, we analysed the response of mouse retinal explants to NMOSD immunoglobulins (IgG). Mouse retinal explants were treated with purified IgG from patient or control sera for one and three days. We characterized tissue response patterns through morphological changes, chemokine secretion, and complement expression. Mouse retinal explants exhibited a basic proinflammatory response ex vivo, modified by IgG addition. NMOSD IgG, unlike control IgG, increased gliosis and decreased chemokine release (CCL2, CCL3, CCL4, and CXCL-10). Complement component expression by retinal cells remained unaltered by either IgG fraction. We conclude that human NMOSD IgG can possibly bind in the mouse retina, altering the local cellular environment. This intraretinal stress may contribute to retinal degeneration independent of relapse activity in NMOSD, suggesting a primary retinopathy.

C5a complement levels in clinical remission AQP4-IgG-positive NMO patients

BACKGROUND

Neuromyelitis Optica Spectrum Disorders (NMOSD) is an antibody-mediated disorder of the Central Nervous System where a leading role of the complement system has been demonstrated.

OBJECTIVE

To measure the levels of complement factors C3, C4 and C5a in serum and plasma of clinical remission patients with AQP4-IgG + NMOSD.

METHODS

Twelve patients with NMOSD AQP4 + according to 2015 criteria from a General Hospital in Buenos Aires, Argentina, were included in the study, and 19 age- and sex-matched healthy volunteers as a control group (HC). AQP4 antibodies were measured in serum by CBA analysis. Fresh blood samples were centrifuged to obtain serum and plasma. C3, C4, and AQP4 antibodies were measured in the serum, whereas C5a was measured in the plasma, which was obtained using Futhan (BD FUT-175®, BD Biosciences, San Jose, CA, USA).

RESULTS

The complement factors, C3, C4, and C5a were measured in all samples. The mean concentration of C3 was 130.7 mg/dl (SD 16.1 mg/dl), and the mean concentration of C4 was 21.6 mg/dl (SD 4.8 mg/dl); both values were within the normal reference range (C3: 84-193 mg/dl; C4: 20-40 mg/dl) and were not significantly different (p > 0.05) from the mean levels in healthy controls (C3: 116.9 mg/dl; C4: 21.9 mg/dl). When analyzing the mean plasma level of C5a, we found a statistically significant difference (p = 0.0444) between the mean concentration of C5a in NMOSD patients (43.1 ng/ml; SD 48.7 ng/ml) and the HC group (17.7 ng/ml; SD 16.7 ng/ ml).

CONCLUSIONS

In conclusion, the present study demonstrates that plasma C5a may be interesting to investigate as a potential biomarker of disease activity in NMOSD, in a larger and prospective cohort.

Increased peripheral inflammatory responses in myelin oligodendrocyte glycoprotein associated disease and aquaporin-4 antibody positive neuromyelitis optica spectrum disorder

Autoantibody-associated demyelinating diseases of the central nervous system such as myelin oligodendrocyte glycoprotein-antibody associated disease (MOGAD) and aquaporin 4-antibody positive neuromyelitis optica spectrum disorders (AQP4+ NMOSD) are rare diseases but can cause severe disability. In both diseases, associated neuroinflammation is accompanied by blood and cerebrospinal fluid cytokine and chemokine signatures, which were shown to be distinct from those observed in patients with multiple sclerosis (MS). In this study, we aimed to confirm and extend these findings by analyzing a larger number of serum cytokines, chemokines and related molecules in patients with MOGAD or AQP4+ NMOSD in comparison to MS, to better understand the pathophysiology and to identify biomarkers potentially useful in clinical practice for diagnostic and treatment purposes. A total of 65 serum cytokines, chemokines and related molecules like growth factors and soluble receptors were measured by Procartaplex multiplex immunoassays in 40 MOGAD, 40 AQP4+ NMOSD and 54 MS patients at baseline. Furthermore, follow-up samples of 25 AQP4+ NMOSD and 40 MOGAD patients were measured after 6-12 months. Selected analytes were validated in a subgroup of samples using other bead-based assays and ELISA. At baseline, 36 analytes in MOGAD and 30 in AQP4+ NMOSD were significantly increased compared to MS. K-means cluster analysis of all significantly altered molecules revealed three distinct groups: Cluster I, including 12 MOGAD, 2 AQP4+ NMOSD and 3 MS patients, had a specific association with 11 IL-6/IL-17A associated cytokines. In this cluster, 9/17 (53%) patients were children. Cluster II with 13 MOGAD, 24 AQP4+ NMOSD and 1 MS patient was associated with 31 upregulated analytes. Cluster III contained 15 MOGAD, 14 AQP4+ NMOSD and 50 MS patients. In cluster II and III the majority were adults (82% and 92%). Most measured analytes remained stable over time. Validation of selected cytokines and chemokines using other analytical methods revealed moderate to high correlation coefficients, but absolute values differed between assays. In conclusion, these results obtained by bead-based multiplex assays highlight a significant association of biomarkers of peripheral inflammation in patients with antibody-associated demyelinating diseases in comparison with MS.

Serum Contactin-1 in CIDP: A Cross-Sectional Study

Objective

To investigate whether serum levels of contactin-1, a paranodal protein, correlate with paranodal injury as seen in patients with CIDP with antibodies targeting the paranodal region.

Methods

Serum contactin-1 levels were measured in 187 patients with CIDP and 222 healthy controls. Paranodal antibodies were investigated in all patients.

Results

Serum contactin-1 levels were lower in patients (N = 41) with paranodal antibodies compared with patients (N = 146) without paranodal antibodies (p < 0.01) and showed good discrimination between these groups (area under the curve 0.84; 95% CI: 0.76–0.93).

Conclusions

These findings suggest that serum contactin-1 levels have the potential to serve as a possible diagnostic biomarker of paranodal injury in CIDP.

Classification of Evidence

This study provides class II evidence that serum contactin-1 levels can discriminate between patients with CIDP with or without paranodal antibodies with a sensitivity of 71% (95% CI: 56%–85%) and a specificity of 97% (95% CI: 83%–100%).

Serum contactin-1 as a biomarker of long-term disease progression in natalizumab-treated multiple sclerosis

BACKGROUND

Natalizumab treatment provides a model for non-inflammation-induced disease progression in multiple sclerosis (MS).

OBJECTIVE

To study serum contactin-1 (sCNTN1) as a novel biomarker for disease progression in natalizumab-treated relapsing-remitting MS (RRMS) patients.

METHODS

Eighty-nine natalizumab-treated RRMS patients with minimum follow-up of 3 years were included. sCNTN1 was analyzed at baseline (before natalizumab initiation), 3, 12, 24 months (M) and last follow-up (median 5.2 years) and compared to 222 healthy controls (HC) and 15 primary progressive MS patients (PPMS). Results were compared between patients with progressive, stable, or improved disability according to EDSS-plus criteria.

RESULTS

Median sCNTN1 levels (ng/mL,) in RRMS (baseline: 10.7, 3M: 9.7, 12M: 10.4, 24M: 10.8; last follow-up: 9.7) were significantly lower compared to HC (12.5; p ⩽ 0.001). It was observed that 48% of patients showed progression during follow-up, 11% improved, and 40% remained stable. sCNTN1 levels were significantly lower in progressors both at baseline and at 12M compared to non-progressors. A 1 ng/mL decrease in baseline sCNTN1 was consistent with an odds ratio of 1.23 (95% confidence interval 1.04-1.45) (p = 0.017) for progression during follow-up.

CONCLUSION

Lower baseline sCNTN1 concentrations were associated with long-term disability progression during natalizumab treatment, making it a possible blood-based prognostic biomarker for RRMS.

The role and mechanisms of Microglia in Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neurological disease that can cause blindness and disability. As the major mediators in the central nervous system, microglia plays key roles in immunological regulation in neuroinflammatory diseases, including NMOSD. Microglia can be activated by interleukin (IL)-6 and type I interferons (IFN-Is) during NMOSD, leading to signal transducer and activator of transcription (STAT) activation. Moreover, complement C3a secreted from activated astrocytes may induce the secretion of complement C1q, inflammatory cytokines and progranulin (PGRN) by microglia, facilitating injury to microglia, neurons, astrocytes and oligodendrocytes in an autocrine or paracrine manner. These processes involving activated microglia ultimately promote the pathological course of NMOSD. In this review, recent research progress on the roles of microglia in NMOSD pathogenesis is summarized, and the mechanisms of microglial activation and microglial-mediated inflammation, and the potential research prospects associated with microglial activation are also discussed.

Protein spectrum changes in exosomes after therapeutic plasma exchange in patients with neuromyelitis optica

INTRODUCTION

Neuromyelitis optica (NMO) is an autoimmune disease with a high rate of blindness and positive for the detection of aquaporin-4 antibody (AQP4) in most patients. NMO acute attacks are managed by high-doses of intravenous methylprednisolone followed by oral taper, and if symptoms fail to resolve, therapeutic plasma exchange (TPE) is added. TPE can remove pathological antibodies and inflammatory factors leading to clinical improvement.

METHODS

A total of 40 TPE fluid collections from the first to fifth TPE treatments were obtained from eight patients. Exosomes were isolated by ultracentrifugation. Mass spectrometry analyses were used to compare protein change in TPE fluid collection exosomes after the first to the fifth TPE treatments in these patients.

RESULTS

We detected 647 exosome proteins through data-independent acquisition analysis. It was found that some unknown functional antibody fragments and complement pathway proteins decreased after TPE treatment. The results revealed a significant involvement of the following two key pathways: the primary immunodeficiency and systemic lupus erythematosus that may be associated with NMO pathophysiology and TPE treatment efficacy (P < .05). A series of complement proteins may contribute to NMO; in addition, the following proteins increased with plasma exchange: complement factor H-related protein 5, bridging integrator 2, neuroplastin, pigment epithelium-derived factor, ficolin-1, extracellular matrix protein 1, and fatty acid-binding protein 5.

CONCLUSION

Our study may provide a new perspective on the pathogenesis and treatment efficacy of NMO.

Increased Expressions and Roles of CC Chemokine Ligand 21 and CC Chemokine Ligand 25 in Chronic Rhinosinusitis with Nasal Polyps

INTRODUCTION

Chronic rhinosinusitis (CRS) is a local inflammation of the nasal mucosa and sinus that persists for >12 weeks. As CC chemokine ligand (CCL) 19 expression is known to be elevated in CRS, and CCL 19, CCL21, and CCL25 share the same atypical chemokine receptor 4, so we focused on CCL21 and CCL25.

OBJECTIVES

To investigate the expression of CCL21 and CCL25 in different types of CRS and their significance in CRS development.

METHODS

A total of 116 patients participated in the study, and uncinate process mucosa or nasal polyp (NP) specimens were collected during surgery. Western blotting and immunohistochemistry were performed to detect the expression of CCL21 and CCL25, respectively, in the nasal mucosa. Immunofluorescence was used to determine their cellular localization in NPs, whereas macrophage culture was used to determine their relationships with macrophages.

RESULTS

Immunohistochemistry revealed that the expressions of CCL21 and CCL25 were increased in NPs only. Western blotting revealed that these expressions were gradually increased in control, CRS without NP and CRS with NP groups and were positively correlated with disease severity. Furthermore, increased expressions of CCL21 and CCL25 in NPs were not related to eosinophil infiltration. Immunofluorescence results demonstrated colocalization of CCL25+ cells and CD68+ macrophages. CCL25 expression was increased in macrophage culture, especially in M1 macrophages, while CCL21 expression was not significantly associated with macrophages.

CONCLUSIONS

CCL21 and CCL25 were significantly upregulated in NPs and positively correlated with disease severity. CCL25 upregulation was related to M1 macrophages.

Proportions of Th17 cells and Th17-related cytokines in neuromyelitis optica spectrum disorders patients: A meta-analysis

BACKGROUND

T helper (Th17) cells play an important role in many autoimmune diseases. In this meta-analysis, we aimed to specify the proportion of Th17 cells and the levels of Th17-related cytokines in neuromyelitis optica spectrum disorders (NMOSD) patients, we did this meta-analysis.

METHODS

Using previously reported data from PubMed, EMBASE, and Web of Science and Cochrane, we explored the proportion of Th17 cells in CD4⁺ T cells in peripheral blood (PB) and the level of Th17-related cytokines, such as interleukin (IL)1β, IL6, IL17, IL21, IL22, IL23 and transforming growth factor -beta (TGFβ), in cerebrospinal fluid (CSF), plasma, and serum in NMOSD patients compared to control group and multiple sclerosis (MS) patients.

RESULTS

In total, 38 trials were included for our analysis. Results showed that the proportion of Th17 cells was higher in NMOSD patients than in the control and MS groups. The levels of IL1β, IL6, IL17 and IL21 in CSF and plasma, and IL6, IL21, IL22, and IL23 in the serum were higher in NMOSD patients than in the control group. The levels of IL6 in CSF and serum and IL17 in plasma and serum were higher in NMOSD patients than in MS patients.

CONCLUSION

The proportion of Th17 cells and the levels of Th17-related cytokines was increased in NMOSD patients compared with the control group and MS patients. The results of this meta-analysis indicated that Th17 cells and Th17-associated cytokines may play an essential role in the pathogenesis of NMOSD. PROSPERO registration: CRD42019128785.

Mast cells: A key component in the pathogenesis of Neuromyelitis Optica Spectrum Disorder?

Neuromyelitis Optica Spectrum Disorder (NMOSD) is characterized as an autoimmune, inflammatory and demyelinating disease of the Central Nervous System (CNS). Its pathogenesis is due to the presence of anti-aquaporin 4 immunoglobulin G1 antibodies (anti-AQP4IgG), with presence of lymphocytes T Helper 1 and 17 (TH1 and TH17), in addition to previous neuroinflammation. The Mast cell (MC) is a granular cell present in all vascularized tissues, close to vessels, nerves, and meninges. In CNS, MCs are in the area postrema, choroid plexus, thalamus and hypothalamus. MC has ability to transmigrate between the nervous tissue and the lymphoid organs, interacting with the cells of both systems. These cells reach the CNS during development through vessel migration. Most MCs reside on the abluminal side of the vessels, where it can communicate with neurons, glial cells, endothelial cells and the extracellular matrix. Considering the role of MCs in neurodegenerative diseases has been extensively discussed, we hypothesized MCs participate in the pathogenesis of NMOSD. This cell represents an innate and adaptive immune response regulator, capable of faster responses than microglial cells. The study of MCs in NMOSD can help to elucidate the pathogenesis of this disease and guide new research for the treatment of patients in the future. We believe this cell is an important component in the cascade of NMOSD neuroinflammation.