The Involvement of HLA Class II Alleles in Multiple Sclerosis: A Systematic Review with Meta-analysis

A computational approach to matching multiple sclerosis-related, IGH CDR3s with a MBP epitope

In multiple sclerosis (MS), T-cell receptors (TCRs) and antibodies specifically target the main structural proteins of myelin, including myelin basic protein (MBP), especially a specific, canonical, immunoglobulin (IG)-targeted MBP epitope. Efficient computational analyses to diagnose or monitor autoimmune conditions, which could have broad applicability in clinical trials or in diagnoses, remains a challenge. As such, we considered the possibility that focusing on the immunoglobin heavy chain (IGH) complementarity determining region-3 (CDR3) amino acid sequences could support the development of an efficient, convenient, and user-friendly approach to detecting or assessing IGH targets in MS. Thus, we applied a chemical complementarity scoring algorithm, extensively benchmarked in many cancer settings, to assess the combined electrostatic and hydrophobic attractiveness of large numbers of (individual patient) IGH CDR3s and the canonical IG MBP epitope. Samples and controls were filtered to only include CDR3s above a baseline chemical complementarity score. Then, the frequency of each unique IGH CDR3 (with the minimum MBP epitope complementarity) in the MS samples was compared to the same parameter for the control sample. Specifically, a greater number of high frequency IGH CDR3s, with chemically complementary to the canonical MBP epitope, was detected in 47 out of 48 MS-control comparisons, in most cases representing a p < 0.0001. With continued development, this approach has the potential to lead to a user-friendly computational screening tool for patients at risk for developing MS. Additional results indicate that the methodology could also be applied to antigen epitope discovery.

Interleukin in Immune-Mediated Diseases: An Updated Review

The immune system comprises various regulators and effectors that elicit immune responses against various attacks on the body. The pathogenesis of autoimmune diseases is derived from the deregulated expression of cytokines, the major regulators of the immune system. Among cytokines, interleukins have a major influence on immune-mediated diseases. These interleukins initiate the immune response against healthy and normal cells of the body, resulting in immune-mediated disease. The major interleukins in this respect are IL-1, IL-3, IL-4, IL-6, IL-10 and IL-12 which cause immune responses such as excessive inflammation, loss of immune tolerance, altered T-cell differentiation, immune suppression dysfunction, and inflammatory cell recruitment. Systemic Lupus Erythematosus (SLE) is an autoimmune illness characterized by dysregulation of interleukins. These immune responses are the signs of diseases such as rheumatoid arthritis, inflammatory bowel disease, psoriasis, type I diabetes, and multiple sclerosis.

The impact of HLA-DRB1 alleles in a Hellenic, Pediatric-Onset Multiple Sclerosis cohort: Implications on clinical and neuroimaging profile

BACKGROUND

Pediatric-Onset Multiple Sclerosis (POMS) is considered a complex disease entity and several genetic, hormonal, and environmental factors have been associated with disease pathogenesis. Linkage studies in Caucasians have consistently suggested the human leukocyte antigen (HLA) polymorphisms, as the genetic locus most strongly linked to MS, with the HLA-DRB1*15:01 allele, being associated with both adult and pediatric MS patients. Here we aim to investigate the prevalence of the HLA-DRB1 alleles among a Hellenic POMS cohort and any possible associations with clinical and imaging disease features.

MATERIALS AND METHODS

100 POMS patients fulfilling the IPMSSG criteria, 168 Adult-Onset MS (AOMS) patients, and 246 Healthy Controls (HCs) have been enrolled. HLA genotyping was performed with a standard low-resolution sequence-specific oligonucleotide (SSO) technique.

RESULTS

POMS patients display a significantly increased HLA-DRB1*03 frequency compared to both HCs [24% vs. 12.6%, OR [95%CI]: 2.19 (1.21-3.97), p=0.016) and AOMS (24% vs. 13.1%, OR [95%CI]: 2.1 (1.1-3.98), p=0.034] respectively. HLA-DRB1*03-carriers display reduced risk for brainstem lesion development (OR [CI 95%]:0.19 (0.06-0.65), p=0.011). A significantly lower frequency of HLA-DRB1*07 (4% vs 13.4%, OR (95% CI): 0.27 (0.09-0.78), p= 0.017) and HLA-DRB1*11 (37% vs 52%, OR [95% CI]: 0.54 (0.34-0.87), p= 0.016) was observed in POMS compared to HCs.

CONCLUSION

The HLA-DRB1*03 allele was associated with a higher risk for POMS, replicating our previous findings, and with a lower risk for brainstem lesion development, a common clinical and neuroimaging feature in POMS, while HLA-DRB1*07 and HLA-DRB1*11 display a protective role. These findings expand the existing knowledge of HLA associations and POMS.

Tumefactive demyelinating lesions: A literature review of recent findings

Tumefactive demyelinating lesion is a variant of multiple sclerosis that is a diagnostic challenge. Tumefactive demyelinating lesion requires extensive work-up as its clinical and radiological features are often indistinguishable from other central nervous system lesions, such as tumors. Diagnosis is further complicated by the increasing recognition that tumefactive demyelinating lesions can occur alongside, evolve into, or develop from numerous conditions other than multiple sclerosis, pointing to a possible overlapping etiology. We review herein relevant studies from 2017 onwards to provide a current view on the pathogenesis, clinical and imaging findings, novel diagnostic techniques for differential diagnoses, and management of tumefactive demyelinating lesions.

The effect of type 1 diabetes protection and susceptibility associated HLA class II genotypes on DNA methylation in immune cells

The HLA region, especially HLA class I and II genes, which encode molecules for antigen presentation to T cells, plays a major role in the predisposition to autoimmune disorders. To clarify the mechanisms behind this association, we examined genome-wide DNA methylation by microarrays to cover over 850,000 CpG sites in the CD4+ T cells and CD19+ B cells of healthy subjects homozygous either for DRB1*15-DQA1*01-DQB1*06:02 (DR2-DQ6, n = 14), associated with a strongly decreased T1D risk, DRB1*03-DQA1*05-DQB1*02 (DR3-DQ2, n = 19), or DRB1*04:01-DQA1*03-DQB1*03:02 (DR4-DQ8, n = 17), associated with a moderately increased T1D risk. In total, we discovered 14 differentially methylated CpG probes, of which 10 were located in the HLA region and six in the HLA-DRB1 locus. The main differences were between the protective genotype DR2-DQ6 and the risk genotypes DR3-DQ2 and DR4-DQ8, where the DR2-DQ6 group was hypomethylated compared to the other groups in all but four of the differentially methylated probes. The differences between the risk genotypes DR3-DQ2 and DR4-DQ8 were small. Our results indicate that HLA variants have few systemic effects on methylation and that their effect on autoimmunity is conveyed directly by HLA molecules, possibly by differences in expression levels or function.

Validation of tag SNPs for multiple sclerosis HLA risk alleles across the 1000 genomes panel

Currently, the genetic variants strongly associated with risk for Multiple Sclerosis (MS) are located in the Major Histocompatibility Complex. This includes DRB1*15:01 and DRB1*15:03 alleles at the HLA-DRB1 locus, the latter restricted to African populations; the DQB1*06:02 allele at the HLA-DQB1 locus which is in high linkage disequilibrium (LD) with DRB1*15:01; and protective allele A*02:01 at the HLA-A locus. HLA allele identification is facilitated by co-inherited ('tag') single nucleotide polymorphisms (SNPs); however, SNP validation is not typically done outside of the discovery population. We examined 19 SNPs reported to be in high LD with these alleles in 2,502 healthy subjects included in the 1000 Genomes panel having typed HLA data. Examination of 3 indices (LD R2 values, sensitivity and specificity, minor allele frequency) revealed few SNPs with high tagging performance. All SNPs examined that tag DRB1*15:01 were in perfect LD in the British population; three showed high tagging performance in 4 of the 5 European, and 2 of the 4 American populations. For DQB1*06:02, with no previously validated tag SNPs, we show that rs3135388 has high tagging performance in one South Asian, one American, and one European population. We identify for the first time that rs2844821 has high tagging performance for A*02:01 in 5 of 7 African populations including African Americans, and 4 of the 5 European populations. These results provide a basis for selecting SNPs with high tagging performance to assess HLA alleles across diverse populations, for MS risk as well as for other diseases and conditions.

Genetic susceptibility and causal pathway analysis of eye disorders coexisting in multiple sclerosis

Introduction

The comorbidity of optic neuritis with multiple sclerosis has been well recognized. However, the causal association between multiple sclerosis and optic neuritis, as well as other eye disorders, remains incompletely understood. To address these gaps, we investigated the genetically relationship between multiple sclerosis and eye disorders, and explored potential drugs.

Methods

In order to elucidate the genetic susceptibility and causal links between multiple sclerosis and eye disorders, we performed two-sample Mendelian randomization analyses to examine the causality between multiple sclerosis and eye disorders. Additionally, causal single-nucleotide polymorphisms were annotated and searched for expression quantitative trait loci data. Pathway enrichment analysis was performed to identify the possible mechanisms responsible for the eye disorders coexisting with multiple sclerosis. Potential therapeutic chemicals were also explored using the Cytoscape.

Results

Mendelian randomization analysis revealed that multiple sclerosis increased the incidence of optic neuritis while reducing the likelihood of concurrent of cataract and macular degeneration. Gene Ontology enrichment analysis implicated that lymphocyte proliferation, activation and antigen processing as potential contributors to the pathogenesis of eye disorders coexisting with multiple sclerosis. Furthermore, pharmaceutical agents traditionally employed for allograft rejection exhibited promising therapeutic potential for the eye disorders coexisting with multiple sclerosis.

Discussion

Multiple sclerosis genetically contributes to the development of optic neuritis while mitigating the concurrent occurrence of cataract and macular degeneration. Further research is needed to validate these findings and explore additional mechanisms underlying the comorbidity of multiple sclerosis and eye disorders.

Investigation of molecular interaction and conformational stability of disease concomitant to HLA-DRβ3

Human leucocyte antigen DRβ3 is associated with specific autoimmune thyroid disease and plays a vital role in the progression of Grave's disease. The available crystallographic structure of the HLA DRA, DRβ3*0101, was selected and used to generate mutation at position 57 from valine amino acid to Aspartic acid (D), Glutamic acid (E), Alanine (A), and Serine (S) amino acids by computational modeling approach. Mutant models were minimized, and stable conformation was chosen based on the lowest root mean square deviation value. Molecular docking assessed the best binding affinity of ligands C1, C2, C3, and C4 with wild-type and mutant HLA-DRβ3 models. Molecular dynamics simulation studies were executed to evaluate the stability of selected hits with wild-type and mutant dock complexes. The C3 has shown good binding affinity with wild-type and selected mutants; V57A, V57E, and V57D. Structural and molecular dynamics insights reveal the differences between wild-type and mutant-type HLA-DRβ3, which could help design novel antagonist molecules against autoimmune thyroid disorder.Communicated by Ramaswamy H. Sarma.

Decision trees to evaluate the risk of developing multiple sclerosis

Introduction

Multiple sclerosis (MS) is a persistent neurological condition impacting the central nervous system (CNS). The precise cause of multiple sclerosis is still uncertain; however, it is thought to arise from a blend of genetic and environmental factors. MS diagnosis includes assessing medical history, conducting neurological exams, performing magnetic resonance imaging (MRI) scans, and analyzing cerebrospinal fluid. While there is currently no cure for MS, numerous treatments exist to address symptoms, decelerate disease progression, and enhance the quality of life for individuals with MS.

Methods

This paper introduces a novel machine learning (ML) algorithm utilizing decision trees to address a key objective: creating a predictive tool for assessing the likelihood of MS development. It achieves this by combining prevalent demographic risk factors, specifically gender, with crucial immunogenetic risk markers, such as the alleles responsible for human leukocyte antigen (HLA) class I molecules and the killer immunoglobulin-like receptors (KIR) genes responsible for natural killer lymphocyte receptors.

Results

The study included 619 healthy controls and 299 patients affected by MS, all of whom originated from Sardinia. The gender feature has been disregarded due to its substantial bias in influencing the classification outcomes. By solely considering immunogenetic risk markers, the algorithm demonstrates an ability to accurately identify 73.24% of MS patients and 66.07% of individuals without the disease.

Discussion

Given its notable performance, this system has the potential to support clinicians in monitoring the relatives of MS patients and identifying individuals who are at an increased risk of developing the disease.

The prevalence and incidence of multiple sclerosis over the past 20 years in northern Japan

OBJECTIVES

The prevalence of multiple sclerosis (MS) in East Asia is thought to be lower than in Western countries. Globally, there is a trend of increasing MS prevalence. We investigated the changes in the prevalence and clinical phenotype of MS in the Tokachi province of Hokkaido in northern Japan, from 2001 to 2021.

METHODS

Data processing sheets were sent to all related institutions inside and outside the Tokachi area of Hokkaido island in Japan and were collected from April to May 2021. The prevalence according to the Poser's diagnostic criteria for MS was determined on March 31, 2021.

RESULTS

In 2021, the crude MS prevalence in northern Japan was 22.4/100,000 (95% confidence interval, 17.6-28.0). The prevalences of MS standardized by the Japanese national population in 2001, 2006, 2011, 2016, and 2021 were 6.9, 11.5, 15.3, 18.5, and 23.3, respectively. The female/male ratio was 4.0 in 2021, increased from 2.6 in 2001. We checked the prevalence using the 2017 revised McDonald criteria, and found only additional male patient who had not fulfilled Poser's criteria. The age- and sex-adjusted incidence of MS per 100,000 individuals increased from 0.09 in 1980-1984 to 0.99 in 2005-2009; since then, it has remained stable. The proportions of primary-progressive, relapsing-remitting, and secondary-progressive MS types in 2021 were 3%, 82%, and 15%, respectively.

CONCLUSION

Our results demonstrated a consistent increase in the prevalence of MS among the northern Japanese over 20 years, particularly in females, and consistently lower rates of progressive MS in northern Japan than elsewhere in the world.

First-line disease modifying treatments in pediatric-onset multiple sclerosis in Greece: therapy initiation at more advanced age is the main cause of treatment failure, in a retrospective observational study, with a cohort from a single Multiple Sclerosis Center

OBJECTIVES

Long-term immunomodulatory therapy of pediatric onset-multiple sclerosis (POMS) is based mainly on published case series and internationally agreed guidelines. Relevant studies in the Greek population are absent from the literature. The purpose of this study is to present data on the efficacy and safety of the 1st line immunomodulatory drugs in the treatment of POMS patients.

MATERIALS AND METHODS

The present study included 27 patients meeting the IPMSSG criteria for POMS and who are monitored at the outpatient clinic of the Multiple Sclerosis and Demyelinating Diseases Unit (MSDDU), of the 1st Neurological Department, University Hospital of Aeginition. All patients received 1st line immunomodulatory drugs as initial therapy. Clinical, laboratory, and imaging parameters of the disease were recorded before and after treatment.

RESULTS

Post-treatment, a significant reduction of the relapse number (mean ± SD: 2.0 ± 1.0 vs 1.2 ± 1.6, p = 0.002), EDSS progression (mean ± SD: 1.5 ± 0.8 vs 0.9 ± 0.7, p = 0.005) and ARR (mean ± SD: 1.5 ± 0.7 vs 0.4 ± 0.5, p = 0.0001) was observed, while no changes were observed in the EDSS score, (mean ± SD: 1.8 ± 0.6 vs 1.9. 0.6, p = 0.60). Advanced age at treatment initiation increased the risk for drug discontinuation before 24 months of therapy (HR = 0.6, 95% CI (0.35-0.99), p = 0.04).

CONCLUSIONS

Most pediatric patients are forced to switch to either more efficacious 1st line or 2nd line drugs. Additionally, our study suggests that older age at the time of the 1st line treatment initiation, contributes to earlier drug discontinuation.

Saliva microbiome, dietary, and genetic markers are associated with suicidal ideation in university students

Here, salivary microbiota and major histocompatibility complex (MHC) human leukocyte antigen (HLA) alleles were compared between 47 (12.6%) young adults with recent suicidal ideation (SI) and 325 (87.4%) controls without recent SI. Several bacterial taxa were correlated with SI after controlling for sleep issues, diet, and genetics. Four MHC class II alleles were protective for SI including DRB1*04, which was absent in every subject with SI while present in 21.7% of controls. Increased incidence of SI was observed with four other MHC class II alleles and two MHC class I alleles. Associations between these HLA alleles and salivary bacteria were also identified. Furthermore, rs10437629, previously associated with attempted suicide, was correlated here with SI and the absence of Alloprevotella rava, a producer of an organic acid known to promote brain energy homeostasis. Hence, microbial-genetic associations may be important players in the diathesis-stress model for suicidal behaviors.

B-Cell NHL Subtype Risk Associated with Autoimmune Conditions and PRS

BACKGROUND

A previous International Lymphoma Epidemiology (InterLymph) Consortium evaluation of joint associations between five immune gene variants and autoimmune conditions reported interactions between B-cell response-mediated autoimmune conditions and the rs1800629 genotype on risk of B-cell non-Hodgkin lymphoma (NHL) subtypes. Here, we extend that evaluation using NHL subtype-specific polygenic risk scores (PRS) constructed from loci identified in genome-wide association studies of three common B-cell NHL subtypes.

METHODS

In a pooled analysis of NHL cases and controls of Caucasian descent from 14 participating InterLymph studies, we evaluated joint associations between B-cell-mediated autoimmune conditions and tertile (T) of PRS for risk of diffuse large B-cell lymphoma (DLBCL; n = 1,914), follicular lymphoma (n = 1,733), and marginal zone lymphoma (MZL; n = 407), using unconditional logistic regression.

RESULTS

We demonstrated a positive association of DLBCL PRS with DLBCL risk [T2 vs. T1: OR = 1.24; 95% confidence interval (CI), 1.08-1.43; T3 vs. T1: OR = 1.81; 95% CI, 1.59-2.07; P-trend (Ptrend) < 0.0001]. DLBCL risk also increased with increasing PRS tertile among those with an autoimmune condition, being highest for those with a B-cell-mediated autoimmune condition and a T3 PRS [OR = 6.46 vs. no autoimmune condition and a T1 PRS, Ptrend < 0.0001, P-interaction (Pinteraction) = 0.49]. Follicular lymphoma and MZL risk demonstrated no evidence of joint associations or significant Pinteraction.

CONCLUSIONS

Our results suggest that PRS constructed from currently known subtype-specific loci may not necessarily capture biological pathways shared with autoimmune conditions.

IMPACT

Targeted genetic (PRS) screening among population subsets with autoimmune conditions may offer opportunities for identifying those at highest risk for (and early detection from) DLBCL.

Natalizumab therapy in patients with pediatric-onset multiple sclerosis in Greece: clinical and immunological insights of time-long administration and future directions-a single-center retrospective observational study

Pediatric-onset multiple sclerosis (MS, POMS) accounts for 3-5% of all MS cases and is characterized by a highly inflammatory profile, often warranting treatment with high-efficacy agents. Our aim is to present real-world data of a series of 18 Hellenic POMS patients treated with natalizumab (NTZ) either as adolescents or as adults, after high disease activity has efficiently subsided. Clinical and imaging/laboratory data from 18 POMS patients who have received at least one NTZ infusion were selected in this single-center retrospective observational study. Human leukocyte antigen (HLA) genotyping was performed with standard low-resolution sequence-specific oligonucleotide techniques. Eighteen patients with a mean age of disease onset of 15.3 ± 2.4 years were treated with NTZ with a mean of 51.7 ± 46.4 infusions, 6 as adolescents and 12 as adults. 22.2% were treatment naïve. At the end of the observational period, patients of both groups remained relapse-free, with no radiological activity and significantly reduced disability accumulation. No evidence of disease activity (NEDA)-3 status was achieved in 66.7% of all patients, 58.3% in the adult-treated, and 83.3% in the adolescent-treated POMS patients. NTZ was generally well tolerated. Only 5 adverse events were observed, in 3 patients who were carriers of the HLA-DRB1*15 (HLA-DRB1*15/HLA-DRB1*11 and HLA-DRB1*15/HLA-DRB1*13 genotypes), 1 homozygous for the HLA-DRB1*03 allele and 1 heterozygous for HLA-DRB1*04 and HLA-DRB1*16 alleles. NTZ is highly efficacious and mostly safe for POMS patients with high disease activity in all age groups. The role of immunogenetics in personalized patient evaluation and treatment needs to be further investigated.

HLA-G and the MHC Cusp Theory

Human leukocyte antigens (HLA) are significant genetic risk factors in a long list of diseases. However, the mechanisms underlying these associations remain elusive in many cases. The best-characterized function of classical major histocompatibility complex (MHC) antigens is to allow safe presentation of antigenic peptides via a self/non-self-discrimination process. Therefore, most hypotheses to date have posited that the observed associations between certain HLA molecules and human diseases involve antigen presentation (AP). However, these hypotheses often represent inconsistencies with current knowledge. To offer answers to the inconsistencies, a decade ago we have invoked the MHC Cusp theory, postulating that in addition to its main role in AP, the MHC codes for allele-specific molecules that act as ligands in a conformationally-conserved cusp-like fold, which upon interaction with cognate receptors can trigger MHC-associated diseases. In the ensuing years, we have provided empirical evidence that substantiates the theory in several HLA-Class II-associated autoimmune diseases. Notably, in a recent study we have demonstrated that HLA-DRB1 alleles known to protect against several autoimmune diseases encode a protective epitope at the cusp region, which activates anti-inflammatory signaling leading to transcriptional and functional modulatory effects. Relevant to the topic of this session, cusp ligands demonstrate several similarities to the functional effects of HLA-G. The overall goal of this opinion article is to delineate the parallels and distinctive features of the MHC Cusp theory with structural and functional aspects of HLA-G molecules.

Fingolimod as a first- or second-line treatment in a mini-series of young Hellenic patients with adolescent-onset multiple sclerosis: focus on immunological data

BACKGROUND

Pediatric onset multiple sclerosis(POMS) is characterized by a highly active profile, often warranting treatment with high efficacy disease-modulating therapies (DMTs). Fingolimod, an oral sphingosine-1-phosphate receptor modulator, is the first Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved DMT for the treatment of POMS.

OBJECT

Our aim is to present real-world data of seven fingolimod-treated POMS-patients, recruited in a single MS center in Greece.

METHODS

Clinical and imaging/laboratory data from 7 Hellenic patients fulfilling the International Pediatric Multiple Sclerosis Study Group (IPMSSG) criteria for POMS diagnosis, who have received fingolimod treatment, were selected. Human leukocyte antigen (HLA) genotyping was performed with standard low-resolution sequence-specific oligonucleotide techniques.

RESULTS

Three patients were treatment-naïve adolescents who received fingolimod as first-line treatment. Two experienced ongoing clinical and radiological disease activity and have been switched to natalizumab. The remaining cases were post-adolescent adults with POMS, where the vast majority experienced total/near-total disease remission. Fingolimod was generally well-tolerated. Two patients with high disease activity carried the HLA-DRB1*03 allele, while five patients were carriers of at least one of the HLA-DRB1*04, HLA-DRB1*13, and HLA-DRB1*14 alleles, which when not combined with HLA-DRB1*03 showed a trend towards a more favorable clinical course. Fingolimod responders showed a trend towards increased CD(16-56)⁺NK cell counts in immunophenotyping assays.

CONCLUSIONS

Our preliminary results support that response of POMS patients to fingolimod may be partially dependent on age and previous DMT, with younger and treatment-naïve patients presenting worse outcomes. The role of immunogenetics and immunophenotyping in personalized treatment warrants investigation in larger and more diverse populations.

The Role of Distinct Subsets of Macrophages in the Pathogenesis of MS and the Impact of Different Therapeutic Agents on These Populations

Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS). Besides the vital role of T cells, other immune cells, including B cells, innate immune cells, and macrophages (MФs), also play a critical role in MS pathogenesis. Tissue-resident MФs in the brain’s parenchyma, known as microglia and monocyte-derived MФs, enter into the CNS following alterations in CNS homeostasis that induce inflammatory responses in MS. Although the neuroprotective and anti-inflammatory actions of monocyte-derived MФs and resident MФs are required to maintain CNS tolerance, they can release inflammatory cytokines and reactivate primed T cells during neuroinflammation. In the CNS of MS patients, elevated myeloid cells and activated MФs have been found and associated with demyelination and axonal loss. Thus, according to the role of MФs in neuroinflammation, they have attracted attention as a therapeutic target. Also, due to their different origin, location, and turnover, other strategies may require to target the various myeloid cell populations. Here we review the role of distinct subsets of MФs in the pathogenesis of MS and different therapeutic agents that target these cells.

Whole-exome sequencing reveals the major genetic factors contributing to neuromyelitis optica spectrum disorder in Chinese patients with aquaporin 4-IgG seropositivity

BACKGROUND AND OBJECTIVE

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease. Although genetic factors are involved in its pathogenesis, limited evidence is available in this area. The aim of the present study was to identify the major genetic factors contributing to NMOSD in Chinese patients with aquaporin 4 (AQP4)-IgG seropositivity.

METHODS

Whole-exome sequencing (WES) was performed on 228 Chinese NMOSD patients seropositive for AQP4-IgG and 1400 healthy controls in Guangzhou, South China. Human leukocyte antigen (HLA) sequencing was also utilized. Genotype model and haplotype, gene burden, and enrichment analyses were conducted.

RESULTS

A significant region of the HLA composition is on chromosome 6, and great variation was observed in DQB1, DQA2 and DQA1. HLA sequencing confirmed that the most significant allele was HLA-DQB1*05:02 (p < 0.01, odds ratio [OR] 3.73). The genotype model analysis revealed that HLA-DQB1*05:02 was significantly associated with NMOSD in the additive effect model and dominant effect model (p < 0.05). The proportion of haplotype "HLA-DQB1*05:02-DRB1*15:01" was significantly greater in the NMOSD patients than the controls, at 8.42% and 1.23%, respectively (p < 0.001, OR 7.39). The gene burden analysis demonstrated that loss-of-function mutations in NOP16 were more common in the NMOSD patients (11.84%) than the controls (5.71%; p < 0.001, OR 2.22). The IgG1-G390R variant was significantly more common in NMOSD, and the rate of the T allele was 0.605 in patients and 0.345 in the controls (p < 0.01, OR 2.92). The enrichment analysis indicated that most of the genetic factors were mainly correlated with nervous and immune processes.

CONCLUSIONS

Human leukocyte antigen is highly correlated with NMOSD. NOP16 and IgG1-G390R play important roles in disease susceptibility.

Epstein-Barr Virus and Multiple Sclerosis

Multiple sclerosis (MS) is a neurologic disease affecting myelinated nerves in the central nervous system (CNS). The disease often debuts as a clinically isolated syndrome, e.g., optic neuritis (ON), which later develops into relapsing-remitting (RR) MS, with temporal attacks or primary progressive (PP) MS. Characteristic features of MS are inflammatory foci in the CNS and intrathecal synthesis of immunoglobulins (Igs), measured as an IgG index, oligoclonal bands (OCBs), or specific antibody indexes. Major predisposing factors for MS are certain tissue types (e.g., HLA DRB1*15:01), vitamin D deficiency, smoking, obesity, and infection with Epstein-Barr virus (EBV). Many of the clinical signs of MS described above can be explained by chronic/recurrent EBV infection and current models of EBV involvement suggest that RRMS may be caused by repeated entry of EBV-transformed B cells to the CNS in connection with attacks, while PPMS may be caused by more chronic activity of EBV-transformed B cells in the CNS. In line with the model of EBV's role in MS, new treatments based on monoclonal antibodies (MAbs) targeting B cells have shown good efficacy in clinical trials both for RRMS and PPMS, while MAbs inhibiting B cell mobilization and entry to the CNS have shown efficacy in RRMS. Thus, these agents, which are now first line therapy in many patients, may be hypothesized to function by counteracting a chronic EBV infection.

Ozanimod to Treat Relapsing Forms of Multiple Sclerosis: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple sclerosis (MS) is a prevalent and debilitating neurologic condition characterized by widespread neurodegeneration and the formation of focal demyelinating plaques in the central nervous system. Current therapeutic options are complex and attempt to manage acute relapse, modify disease, and manage symptoms. Such therapies often prove insufficient alone and highlight the need for more targeted MS treatments with reduced systemic side effect profiles. Ozanimod is a novel S1P (sphingosine-1-phosphate) receptor modulator used for the treatment of clinically isolated syndrome, relapsing–remitting, and secondary progressive forms of multiple sclerosis. It selectively modulates S1P1 and S1P5 receptors to prevent autoreactive lymphocytes from entering the CNS where they can promote nerve damage and inflammation. Ozanimod was approved by the US Food and Drug Administration (US FDA) for the management of multiple sclerosis in March 2020 and has been proved to be both effective and well tolerated. Of note, ozanimod is associated with the following complications: increased risk of infections, liver injury, fetal risk, increased blood pressure, respiratory effects, macular edema, and posterior reversible encephalopathy syndrome, among others. Further investigation including head-to-head clinical trials is warranted to evaluate the efficacy of ozanimod compared with other S1P1 receptor modulators.

Sinomenine Alleviates Murine Experimental Autoimmune Encephalomyelitis Model of Multiple Sclerosis through Inhibiting NLRP3 Inflammasome

Multiple sclerosis (MS) is known as a chronic neuroinflammatory disorder typified by an immune-mediated demyelination process with ensuing axonal damage and loss. Sinomenine is a natural alkaloid with different therapeutic benefits, including anti-inflammatory and immunosuppressive activities. In this study, possible beneficial effects of sinomenine in an MOG-induced model of MS were determined. Sinomenine was given to MOG_35-55-immunized C57BL/6 mice at doses of 25 or 100 mg/kg/day after onset of MS clinical signs till day 30 post-immunization. Analyzed data showed that sinomenine reduces severity of the clinical signs and to some extent decreases tissue level of pro-inflammatory cytokines IL-1β, IL-6, IL-18, TNFα, IL-17A, and increases level of anti-inflammatory IL-10. In addition, sinomenine successfully attenuated tissue levels of inflammasome NLRP3, ASC, and caspase 1 besides its reduction of intensity of neuroinflammation, demyelination, and axonal damage and loss in lumbar spinal cord specimens. Furthermore, immunoreactivity for MBP decreased and increased for GFAP and Iba1 after MOG-immunization, which was in part reversed upon sinomenine administration. Overall, sinomenine decreases EAE severity, which is attributed to its alleviation of microglial and astrocytic mobilization, demyelination, and axonal damage along with its suppression of neuroinflammation, and its beneficial effect is also associated with its inhibitory effects on inflammasome and pyroptotic pathways; this may be of potential benefit for the primary progressive phenotype of MS.