Low levels of vitamin D and the relationship between vitamin D and Th2 axis-related cytokines in neuromyelitis optica spectrum disorders

Sex ratio and age of onset in AQP4 antibody-associated NMOSD: a review and meta-analysis

BACKGROUND

Aquaporin-4 (AQP4) antibody-associated neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system. We have undertaken a systematic review and meta-analysis to ascertain the sex ratio and mean age of onset for AQP4 antibody associated NMOSD. We have also explored factors that impact on these demographic data.

METHODS

A systematic search of databases was conducted according to the PRISMA guidelines. Articles reporting sex distribution and age of onset for AQP4 antibody-associated NMSOD were reviewed. An initially inclusive approach involving exploration with regression meta-analysis was followed by an analysis of just AQP4 antibody positive cases.

RESULTS

A total of 528 articles were screened to yield 89 articles covering 19,415 individuals from 88 population samples. The female:male sex ratio was significantly influenced by the proportion of AQP4 antibody positive cases in the samples studied (p < 0.001). For AQP4 antibody-positive cases the overall estimate of the sex ratio was 8.89 (95% CI 7.78-10.15). For paediatric populations the estimate was 5.68 (95% CI 4.01-8.03) and for late-onset cases, it was 5.48 (95% CI 4.10-7.33). The mean age of onset was significantly associated with the mean life expectancy of the population sampled (p < 0.001). The mean age of onset for AQP4 antibody-positive cases in long-lived populations was 41.7 years versus 33.3 years in the remainder.

CONCLUSIONS

The female:male sex ratio and the mean age of onset of AQP4 antibody-associated NMOSD are significantly higher than MS. The sex ratio increases with the proportion of cases that are positive for AQP4 antibodies and the mean age of onset increases with population life expectancy.

Vitamin D status and neuromyelitis optica spectrum disease: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

There's an increasing body of evidence on vitamin D deficiency and the risk of neuromyelitis optica spectrum disorder (NMOSD). The aim of this meta-analysis was to assess serum vitamin D levels in patients with NMOSD versus healthy controls.

METHODS

We searched PubMed, EMBASE, Cochrane Library, Web of Science and CNKI for publications up to November 2022 and explored the relationship between NMOSD and serum vitamin D levels. The standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated using a random-effects model. Subgroup analysis and sensitivity analysis were applied to explore the sources of heterogeneity. Begg's test, Egger's test, and Egger's funnel plot were adopted to evaluate publication bias.

RESULTS

6 studies (including 319 patients and 595 healthy controls) met the inclusion criteria and all compared vitamin D levels in patients with NMOSD versus healthy controls. Levels of serum vitamin D detected in NMOSD patients were significantly lower than those in healthy controls (SMD=-1.57, 95% CI=-2.27 ∼ -0.87, P<0.001, I2 = 94.6%). The results of the different sensitivity analysis remained statistically significant, which demonstrated the robustness of the meta-analysis. There was no significant publication bias in our meta-analysis (P>0.05).

CONCLUSION

Patients with NMOSD showed significantly reduced vitamin D levels compared with healthy controls. Our findings highlighted the importance of measuring vitamin D levels in patients with NMOSD. Multi-center randomized controlled trials with large samples will further confirm whether the association is casual and modifiable.

Vitamin D status and the risk of neuromyelitis optica spectrum disorders: A systematic review and meta-analysis

BACKGROUND

Previous studies have linked vitamin D deficiency with autoimmune diseases, and recent research has found low vitamin D levels in neuromyelitis optica spectrum disorder (NMOSD) patients. We aimed to determine the variances in serum 25(OH)D levels between NMOSD patients and healthy controls.

METHODS

We searched English and Chinese databases (PubMed, Embase, Cochrane Library, Web of Science, CBM, CNKI, WanFang Med, VIP) for observational studies related to serum 25(OH)D levels in NMOSD patients published up to August 24, 2023. We included studies with healthy controls and compared serum 25(OH)D levels between NMOSD patients and controls. We computed the mean difference (MD) and 95% confidence interval (CI) for continuous variables to evaluate serum 25(OH)D levels and combined odds ratios (ORs) and 95% CIs for dichotomized 25(OH)D data.

RESULTS

Six papers were selected for meta-analysis, including 794 participants (347 in the NMOSD group and 447 in the healthy control group). Meta-analysis showed significantly lower serum 25(OH)D levels in the NMOSD group (MD: -7.83, 95 % CI: -10.99 to -4.68). The risk of 25(OH)D deficiency was 23.36 times higher in the NMOSD group (OR: 23.36, 95 % CI: 0.85 to 640.76, p = 0.06>0.05), with a 94 % occurrence rate. There was no significant difference in the risk of having sufficient 25(OH)D between the groups (p = 0.12>0.05).

CONCLUSION

NMOSD patients have lower serum 25(OH)D levels than healthy controls. However, the current research results do not provide evidence for a causal relationship between serum 25(OH)D levels and the onset of NMOSD. Routine vitamin D supplementation may be advantageous for patients with NMOSD.

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.

Vitamin D deficiency in relation with the systemic and central inflammation during multiple sclerosis

Background

During the last decade, vitamin D (VitD) has become a topic of interest in immune regulation, especially in multiple sclerosis (MS) disease. Amongst the wide range of effects reported for this vitamin on the immune system, a regulatory role on cytokines production has been described. Our aim is to analyze the status of VitD and its correlation with the circulating inflammation and the intrathecal humoral response during MS.

Methods

We analyzed samples of 318 individuals: 108 MS patients and 210 controls. Determination of 25-(OH) VitD3 level in serum was made using electrochemiluminescence method. Circulating inflammatory cytokines (IL-6, IL-8, IL-10, TNF-a, IL12p70 and IL-1b) were investigated using Cytometer Bead Array Technology. The central humoral response was characterized using CSF isofocusing test and IgG Index calculation.

Results

As expected, mean value of VitD was significantly lower in MS group (26 nmol/L) than in control group (34.75 nmol/L) (p=0.002), with a severe deficiency in 67% of MS patients. Mean value of VitD was significantly lower in MS female patients. Regarding cytokines, mean value of TNFa was significantly higher in MS patients with oligoclonal bands of IgG in the CSF. IL6 was positively correlated with IgG level in serum of MS patients.

Conclusions

Our results support the association of VitD deficiency with MS, especially in female patients of our region. However, the vitamin level seems to not correlate with inflammatory cytokines nor with disability. Interestingly, TNFa and IL6 levels were correlated with the intrathecal synthesis of IgG and the circulating IgG level, respectively.

Serum Vitamin D Levels and Status in Thai Optic Neuritis Subjects: A Case-Control Study

Objective

To measure serum total vitamin D or 25-hydroxyvitamin D [25(OH)D] levels and status in immune-based optic neuritis (ON) including neuromyelitis optica spectrum disorder (NMOSD)-ON, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)-ON, autoimmune-ON, and idiopathic-ON and compare them with age- and sex-matched healthy controls. The secondary objective was to analyze the association between serum 25(OH)D levels and ON attack severity (nadir best-corrected visual acuity; nadir BCVA).

Materials and Methods

This was a single-center, case-control study. We enrolled 59 subjects (19 NMOSD-ON, 6 MOGAD-ON, 11 autoimmune-ON, 23 idiopathic-ON) diagnosed with acute immune-based ON (any ON attacks) over 11 years. Electronic medical records were reviewed and demographic data (age at sampling, sex, aquaporin-4 immunoglobulin (AQP4-IgG); myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG); other biomarkers of autoimmune disorders), ON attack severity (nadir BCVA), and serum 25(OH)D levels in the acute phase of ON were collected. Serum 25(OH)D levels of 236 age- and sex-matched healthy controls were assessed.

Results

Mean serum 25(OH)D levels were significantly lower in each group of immune-based ON compared with healthy controls (p < 0.001 for each ON group). However, mean serum 25(OH)D levels were not significantly different between four ON groups (NMOSD-ON, 20.18±5.90 ng/mL; MOGAD-ON, 23.07±4.94 ng/mL; autoimmune-ON, 21.14±5.29 ng/mL; idiopathic-ON, 19.56 ±5.12 ng/mL; p = 0.525). All immune-based ON subjects had vitamin D insufficiency or vitamin D deficiency. The prevalences of vitamin D insufficiency and vitamin D deficiency were significantly higher than in healthy controls in each ON group (both p < 0.05 in each ON group). No associations were observed between serum 25(OH)D levels and ON attack severity (nadir BCVA).

Conclusions

Thai immune-based ON subjects had lower serum 25(OH)D levels and higher prevalence of vitamin D insufficiency and vitamin D deficiency compared with age- and sex-matched healthy controls. Serum 25(OH)D levels were not associated with ON attack severity (nadir BCVA). We highly recommend that serum 25(OH)D levels be screened in all subjects with acute immune-based ON.

Serum levels of interleukin-6 and Vitamin D at the onset of multiple sclerosis and neuromyelitis optica: A pilot study

BACKGROUND

Interleukin-6 (IL-6) is an important mediator in the acute phase of inflammatory diseases such as neuromyelitis optica (NMO) and multiple sclerosis (MS). The level of IL-6 is higher in cerebrospinal fluid and serum of NMO patients compare to MS. Vitamin D has a regulatory effect on IL-6, so it may have a negative correlation with IL-6 in the acute phase of these diseases. This study was performed to evaluate the serum levels of IL-6 and Vitamin D in NMO and MS patients at the onset of disease to find differences that may help in early diagnosis.

MATERIALS AND METHODS

This case-control study was done on patients with the first episode of optic neuritis, transverse myelitis, and area postrema syndrome who were referred to Kashani MS Center in Isfahan, Iran, between January 2018 and January 2020. The serum levels of Vitamin D and IL-6 were assessed using enzyme-linked immunosorbent assay in blood sample taken at the time of first presentation in patients who had a definitive diagnosis of NMO and MS during subsequent workup.

RESULTS

During a 2-year follow-up, definitive diagnosis of NMO was given in 25 cases, and they were compared with 25 cases that were randomly selected from patients with definite MS. Nineteen patients in the NMO group and 21 patients in the MS group were female. The mean age of patients in the NMO and MS groups was 29.64 ± 1.47 and 30.20 ± 1.42, respectively (P = 0.46). The mean of serum level of Vitamin D was 24.88 ± 15.2 in NMO patients and 21.56 ± 18.7 in MS patients without significant difference (P = 0.48). The mean of IL-6 was 30.1 ± 22.62 in the NMO group and 23.35 ± 18.8 in the MS group without significant difference (P = 0.28). The serum levels of Vitamin D were insufficient in both groups. No correlation between Vitamin D and IL-6 levels was found in our study (P > 0.05).

CONCLUSION

Our results showed that serum IL-6 levels were higher at the onset of NMO disease compared with MS. The serum levels of Vitamin D were low in both groups and there was no association between serum levels of Vitamin D and IL-6 in either group. Future studies with large sample size are needed to confirm these findings.

Vitamin D and Ocular Diseases: A Systematic Review

The contributory roles of vitamin D in ocular and visual health have long been discussed, with numerous studies pointing to the adverse effects of vitamin D deficiency. In this paper, we provide a systematic review of recent findings on the association between vitamin D and different ocular diseases, including myopia, age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), dry eye syndrome (DES), thyroid eye disease (TED), uveitis, retinoblastoma (RB), cataract, and others, from epidemiological, clinical and basic studies, and briefly discuss vitamin D metabolism in the eye. We searched two research databases for articles examining the association between vitamin D deficiency and different ocular diseases. One hundred and sixty-two studies were found. There is evidence on the association between vitamin D and myopia, AMD, DR, and DES. Overall, 17 out of 27 studies reported an association between vitamin D and AMD, while 48 out of 54 studies reported that vitamin D was associated with DR, and 25 out of 27 studies reported an association between vitamin D and DES. However, the available evidence for the association with other ocular diseases, such as glaucoma, TED, and RB, remains limited.

IL-33/Vitamin D Crosstalk in Psoriasis-Associated Osteoporosis

Patients with psoriasis (Pso) and, in particular, psoriatic arthritis (PsoA) have an increased risk of developing osteoporosis (OP). It has been shown that OP is among the more common pathologies associated with Pso, mainly due to the well-known osteopenizing conditions coexisting in these patients. Pso and OP share common risk factors, such as vitamin D deficiency and chronic inflammation. Interestingly, the interleukin (IL)-33/ST2 axis, together with vitamin D, is closely related to both Pso and OP. Vitamin D and the IL-33/ST2 signaling pathways are closely involved in bone remodeling, as well as in skin barrier pathophysiology. The production of anti-osteoclastogenic cytokines, e.g., IL-4 and IL-10, is promoted by IL-33 and vitamin D, which are stimulators of both regulatory and Th2 cells. IL-33, together with other Th2 cytokines, shifts osteoclast precursor differentiation towards macrophage and dendritic cells and inhibits receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis by regulating the expression of anti-osteoclastic genes. However, while the vitamin D protective functions in OP and Pso have been definitively ascertained, the overall effect of IL-33 on bone and skin homeostasis, because of its pleiotropic action, is still controversial. Emerging evidence suggests a functional link between vitamin D and the IL-33/ST2 axis, which acts through hormonal influences and immune-mediated effects, as well as cellular and metabolic functions. Based on the actions of vitamin D and IL-33 in Pso and OP, here, we hypothesize the role of their crosstalk in the pathogenesis of both these pathologies.

Upregulation of interleukin (IL)-31, a cytokine producing CXCR1 peripheral immune cells, contributes to the immune abnormalities of autism spectrum disorder

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by communication deficits, impaired social interactions, and restricted stereotypical behaviors. Several immune cells are associated with immune dysfunction in ASD; however, IL-31 has not been explored in ASD. This study aims to investigate the role of inflammatory cytokines and transcription factors of the CXCR1 cells in children with ASD. In the current study, we investigated the cytokines and transcription factors produced by CXCR1⁺ cells (IL-31, IL-9, IL-21R, IL-21, NF-κB p65, RORγT, STAT1, and FoxP3) in peripheral blood mononuclear cells (PBMCs), from children with ASD and typically developing (TD) control children, using flow cytometric analysis. In addition, we measured mRNA and protein expression levels of IL-31 using quantitative real-time PCR and western blot analyses in PBMCs. In our study, children with ASD had increased CXCR1⁺IL-31⁺, CXCR1⁺IL-9⁺, CXCR1⁺IL-21R⁺, CXCR1⁺IL-21⁺, CXCR1⁺NF-κB⁺ p65, CXCR1⁺RORγT⁺, and CXCR1⁺STAT1⁺, and decreased CXCR1⁺FoxP3⁺ cells as compared with cells from the TD control samples. Similarly, children with ASD showed increased IL-31 mRNA and protein expression levels as compared to those of TD control samples. Our results suggest that upregulated production of inflammatory cytokines and transcription factors in CXCR1⁺ cells cause immunological imbalance in children with ASD. Therefore, attenuation of inflammatory cytokines/mediators and transcription factors could have a therapeutic potential in the treatment of ASD.

Neuromyelitis optica

Neuromyelitis optica (NMO; also known as Devic syndrome) is a clinical syndrome characterized by attacks of acute optic neuritis and transverse myelitis. In most patients, NMO is caused by pathogenetic serum IgG autoantibodies to aquaporin 4 (AQP4), the most abundant water-channel protein in the central nervous system. In a subset of patients negative for AQP4-IgG, pathogenetic serum IgG antibodies to myelin oligodendrocyte glycoprotein, an antigen in the outer myelin sheath of central nervous system neurons, are present. Other causes of NMO (such as paraneoplastic disorders and neurosarcoidosis) are rare. NMO was previously associated with a poor prognosis; however, treatment with steroids and plasma exchange for acute attacks and with immunosuppressants (in particular, B cell-depleting agents) for attack prevention has greatly improved the long-term outcomes. Recently, a number of randomized controlled trials have been completed and the first drugs, all therapeutic monoclonal antibodies, have been approved for the treatment of AQP4-IgG-positive NMO and its formes frustes.

The Potential Immunoregulatory Roles of Vitamin D in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoantibody-mediated disease affecting the central nervous system (CNS). Its pathogenesis involves both innate and acquired immune reactions; specific antibody (Aquaporin-4 antibody) and inflammatory cells cause direct damage on lesion sites, while B cell-T cell interactions facilitate the demyelination. However, its etiology is still not fully understood. Vitamin D deficiency is present in numerous autoimmune diseases, including NMOSD. Evidence suggests that low vitamin D levels mayassociate with disease activity and relapse rate in NMOSD, indicating the participation in the pathogenesis of NMOSD. The immunoregulatory roles of vitamin D in both numerous autoimmune diseases and experimental autoimmune encephalomyelitis (EAE) models are increasingly recognized. Recent studies have revealed vitamin D modulation in cytokine production, immune cell development and differentiation, as well as antibody production. By enhancing an anti-inflammatory environment and suppressing the overactivated autoimmune process, vitamin D shows its potential immunoregulatory roles in NMOSD, which could possibly introduce a new therapy for NMOSD patients.

IL-33/IL-31 Axis in Osteoporosis

The study of the immunoskeletal interface has led to the discovery of numerous cytokines involved in the regulation of bone remodeling, providing valuable information on the pathogenesis of osteoporosis. The role of inflammatory cytokines of the Th1 and Th17 profile in osteoporosis is well known. Here we focus on two newly discovered Th2 cytokines, IL-31 and IL-33, whose implications in osteoporosis are recently emerging. Clinical and experimental observations suggest an important role of the IL-33/IL-31 axis in osteoporosis. IL-33 induces IL-31 secretion by Th2 cells and inhibits RANKL-dependent osteoclastogenesis, thus counteracting bone loss. IL-31 influences Th1/Th17 osteoclastogenetic inflammation and limits Th2 osteoprotective processes, thus favoring osteoporosis. Better knowledge of the role of IL-31 and IL-33 and their receptor complexes in osteoporosis could provide an interesting perspective for the development of new and more effective therapies, possibly with less side effects.

Identifying the culprits in neurological autoimmune diseases

The target organ of neurological autoimmune diseases (NADs) is the central or peripheral nervous system. Multiple sclerosis (MS) is the most common NAD, whereas Guillain-Barré syndrome (GBS), myasthenia gravis (MG), and neuromyelitis optica (NMO) are less common NADs, but the incidence of these diseases has increased exponentially in the last few years. The identification of a specific culprit in NADs is challenging since a myriad of triggering factors interplay with each other to cause an autoimmune response. Among the factors that have been associated with NADs are genetic susceptibility, epigenetic mechanisms, and environmental factors such as infection, microbiota, vitamins, etc. This review focuses on the most studied culprits as well as the mechanisms used by these to trigger NADs.

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Neurological autoimmune diseases are caused by a complex interaction between genes, environmental factors, and epigenetic deregulation.

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Infectious agents can cause an autoimmune reaction to myelin epitopes through molecular mimicry and/or bystander activation.

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Gut microbiota dysbiosis contributes to neurological autoimmune diseases.

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Smoking increases the risk of NADs through inflammatory signaling pathways, oxidative stress, and Th17 differentiation.

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Deficiency in vitamin D favors NAD development through direct damage to the central and peripheral nervous system.