Elevated chemokines and cytokines for eosinophils in neuromyelitis optica spectrum disorders

Multimodal brain-derived subtypes of Major depressive disorder differentiate patients for anergic symptoms, immune-inflammatory markers, history of childhood trauma and treatment-resistance

An estimated 30 % of Major Depressive Disorder (MDD) patients exhibit resistance to conventional antidepressant treatments. Identifying reliable biomarkers of treatment-resistant depression (TRD) represents a major goal of precision psychiatry, which is hampered by the clinical and biological heterogeneity. To uncover biologically-driven subtypes of MDD, we applied an unsupervised data-driven framework to stratify 102 MDD patients on their neuroimaging signature, including extracted measures of cortical thickness, grey matter volumes, and white matter fractional anisotropy. Our novel analytical pipeline integrated different machine learning algorithms to harmonize data, perform data dimensionality reduction, and provide a stability-based relative clustering validation. The obtained clusters were characterized for immune-inflammatory peripheral biomarkers, TRD, history of childhood trauma and depressive symptoms. Our results indicated two different clusters of patients, differentiable with 67 % of accuracy: one cluster (n = 59) was associated with a higher proportion of TRD, and higher scores of energy-related depressive symptoms, history of childhood abuse and emotional neglect; this cluster showed a widespread reduction in cortical thickness (d = 0.43-1.80) and volumes (d = 0.45-1.05), along with fractional anisotropy in the fronto-occipital fasciculus, stria terminalis, and corpus callosum (d = 0.46-0.52); the second cluster (n = 43) was associated with cognitive and affective depressive symptoms, thicker cortices and wider volumes. Multivariate analyses revealed distinct brain-inflammation relationships between the two clusters, with increase in pro-inflammatory markers being associated with decreased cortical thickness and volumes. Our stratification of MDD patients based on structural neuroimaging identified clinically-relevant subgroups of MDD with specific symptomatic and immune-inflammatory profiles, which can contribute to the development of tailored personalized interventions for MDD.

The levels of circulating cytokines and risk of neuromyelitis optica spectrum disorder: a Mendelian randomization study

Background

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory autoimmune disease affecting the central nervous system (CNS). NMOSD pathogenesis involves systemic inflammation. However, a causal relationship between circulating cytokine levels and NMOSD remains unclear.

Methods

Mendelian randomization (MR) approaches were used to investigate the potential association between genetically determined circulating 19 inflammatory cytokines and 12 chemokines levels and the risk of developing NMOSD.

Results

After Bonferroni correction, the risk of aquaporin 4-antibody (AQP4-ab)-positive NMOSD was suggested to be causally associated with the circulating levels of three cytokines, including interleukin (IL)-4 [odds ratio (OR): 11.01, 95% confidence interval (CI): 1.16-104.56, P = 0.037], IL-24 (OR: 161.37; 95% CI: 2.46-10569.21, P = 0.017), and C-C motif chemokine 19 (CCL19) (OR: 6.87, 95% CI: 1.78-26.93, P = 0.006).

Conclusion

These findings suggest that a genetic predisposition to higher levels of IL-4, IL-24, and CCL19 may exert a causal effect on the risk of AQP4-ab-positive NMOSD. Further studies are warranted to clarify how these cytokines affect the development of AQP4-ab-positive NMOSD.

Mendelian Randomization Analysis of Circulating Cytokines and Risk of Autoimmune Neuroinflammatory Diseases

Background

Cytokines act a vital role in autoimmune neuroinflammatory diseases (ANDs) with undetermined causal relationships. Mendelian randomization (MR) analysis was performed to estimate the causal effects of circulating levels of cytokines on the risk of ANDs.

Methods

The causal relationship between 34 circulating cytokines and 4 kinds of ANDs, including multiple sclerosis (MS), neuromyelitis optica (NOM), chronic inflammatory demyelinating polyneuropathy (CIDP) and myasthenia gravis (MG) were explored using four methods of MR analysis. MR-PRESSO, MR-Egger regression methods and Cochran's Q statistic were utilized to identify the instrumental variables (IVs) with potential pleiotropy and heterogeneity. The Bonferroni correction was used for multiple group comparisons. P-value less than 3.68E-04 (0.05/ (34*4)) was considered statistically significant.

Results

Negative causal effects of circulating levels of interleukin (IL)-8 (OR = 0.648, 95% CI: 0.494-0.851, P = 0.002) on risk of MS, chemokine (C-C Motif) ligand (CCL)-5 (OR = 0.295, 95% CI: 0.103-0.841, P = 0.022) and stem cell growth factor-beta (SCGF-β) (OR = 0.745, 95% CI: 0.565-0.984, P = 0.038) on risk of CIDP, as well as positive causal effects of circulating levels of IL-2 receptor α (IL-2Rα) (OR = 1.216, 95% CI: 1.120-1.320, P = 3.20E-06) and chemokine C-X-C motif ligand (CXCL)-10 (OR = 1.404, 95% CI: 1.094-1.803, P = 0.008) on MS were observed. Nevertheless, only IL-2Rα still had a causal effect on MS after Bonferroni correction.

Conclusion

The results identify a genetically predicted causal effect of IL-2Rα, IL-8 and CXCL-10 on MS, CCL-5 and SCGF-β on CIDP.

Blood-based inflammatory protein biomarker panel for the prediction of relapse and severity in patients with neuromyelitis optica spectrum disorder: A prospective cohort study

BACKGROUND

To date, most existing models for predicting neuromyelitis optica spectrum disorder (NMOSD) are based primarily on clinical characteristics. Blood-based NMOSD severity and prognostic predictive immune- and inflammation-related biomarkers are needed. We aimed to investigate the associations between plasma inflammatory biomarkers and relapse and attack severity in NMOSD.

METHODS

This two-step, single-center prospective cohort study included discovery and validation cohorts. We quantified 92 plasma inflammatory proteins by using Olink's proximity extension assay and identified differentially expressed proteins in the relapse group (relapse within 1 year of follow-up) and severe attack group. To define a new molecular prognostic model, we calculated the risk score of each patient based on the key protein signatures and validated the results in the validation cohort.

RESULTS

The relapse prediction model, including FGF-23, DNER, GDNF, and SLAMF1, predicted the 1-year relapse risk. The severe attack prediction model, including PD-L1 and MCP-2, predicted the severe clinical attack risk. Both the relapse and severe attack prediction models demonstrated good discriminative ability and high accuracy in the validation cohort.

CONCLUSIONS

Our discovered biomarker signature and prediction models may complement current clinical risk stratification approaches. These inflammatory biomarkers could contribute to the discovery of therapeutic interventions and prevent NMOSD progression.

Early involvement of peripherally derived monocytes in inflammation in an NMO-like mouse model

Neuromyelitis optica (NMO) is an autoimmune inflammatory disease that primarily affects the optic nerve and spinal cord within the central nervous system (CNS). Acute astrocyte injury caused by autoantibodies against aquaporin 4 (NMO-IgG) is a well-established key factor in the pathogenesis, ultimately leading to neuronal damage and patient disability. In addition to these humoral immune processes, numerous innate immune cells were found in the acute lesions of NMO patients. However, the origin and function of these innate immune cells remain unclear in NMO pathogenesis. Therefore, this study aims to analyze the origin and functions of these innate immune cells in an NMO-like mouse model and evaluate their role in the pathophysiology of NMO. The expression of Tmem119 on Iba1 + cells in brain tissue disappeared immediately after the injection of NMO-IgG + human complement mixture, while the expression of P2ry12 remained well-maintained at 1 day after injection. Based on these observations, it was demonstrated that monocytes infiltrate the brain during the early stages of the pathological process and are closely associated with the inflammatory response through the expression of the proinflammatory cytokine IL-1β. Understanding the variations in the expression patterns of P2ry12, Tmem119, and other markers could be helpful in distinguishing between these cell types and further analyzing their functions. Therefore, this research may contribute to a better understanding of the mechanisms and potential treatments for NMO.

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Glial fibrillary acidic protein as a biomarker in neuromyelitis optica spectrum disorder: a current review

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing, often debilitating neuroinflammatory disease, whose predominant clinical manifestations are longitudinally extensive transverse myelitis and optic neuritis. About 80% of the patients with an NMOSD phenotype have pathogenic autoantibodies against the astrocyte water channel aquaporin-4 (AQP4-IgG). While therapeutic options for NMOSD have greatly expanded in recent years, well-established biomarkers for prognosis or treatment response are still lacking. Glial fibrillary acidic protein (GFAP) is mainly expressed in astrocytes and can be detected in cerebrospinal fluid (CSF) and blood of patients with NMOSD.

AREAS COVERED

Here, we comprehensively review the current knowledge on GFAP as a biomarker in NMOSD.

EXPERT OPINION

In patients with AQP4-IgG⁺ NMOSD, GFAP levels are elevated in CSF and serum during acute attacks and correlate with disability, consistent with the pathophysiology of this antibody-mediated astrocytopathy. Serum GFAP levels tend to be higher in AQP4-IgG⁺ NMOSD than in its differential diagnoses, multiple sclerosis, and myelin oligodendrocyte antibody-associated disease. Importantly, serum GFAP levels in AQP4-IgG⁺ NMOSD during remission may be predictive of future disease activity. Serial serum GFAP measurements are emerging as a biomarker to monitor disease activity in AQP4-IgG⁺ NMOSD and could have the potential for application in clinical practice.