HLA-DRB1 polymorphism and susceptibility to multiple sclerosis in the Middle East North Africa region: A systematic review and meta-analysis

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.

Multiple sclerosis and human leukocyte antigen genotypes: Focus on the Middle East and North Africa region

Recent reports have demonstrated that the prevalence of multiple sclerosis (MS) is increasing in the Middle East and North Africa region. There is also emerging evidence regarding the genetic components of MS risk. This review provides an overview of the role of genetic factors in MS susceptibility by examining human leukocyte antigen loci in patients within the Middle East and North Africa region. Most of the genetic studies conducted in the Middle East and North Africa region have been based on case–control designs, which cannot confirm direct causality of genetic variants on MS susceptibility. Moreover, there are very limited and inconsistent studies on human leukocyte antigen class I and II (DQA and DQB) in MS patients of the Middle East and North Africa region. To identify common risk haplotypes in the Middle East and North Africa region or its sub-populations, further longitudinal studies will be required.

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

Multiple Sclerosis (MS) displays a heterogeneous clinical onset and progression, which are mostly unpredictable, but demyelination of the central nervous system (CNS) leads to substantial deficits of sensory, motor, autonomic, and neurocognitive functions. Considering all genetic studies on MS, including the advanced genome-wide association studies, the risk linked to HLA alleles remains the highest among other susceptibility genetic variants. However, given the genetic variability of HLA alleles in different ethnic groups, we conducted a systematic review of reviews and meta-analyses aiming at summarizing all the results on the association between MS and HLA class II genes. We systematically searched meta-analyses and systematic reviews dealing with MS and HLA in all ethnicities. From 154 records, we included 5 articles collecting HLA data from 15,232 MS patients and 24,194 ethnically matched controls. DRB1∗15 (OR ranging from 1.39 in Chinese Han to 2.59 in Caucasians) and DQB1∗06:02 (OR ranging from 1.91 in Caucasians to 2.49 in Colombian) alleles confer an increased risk for MS transethnically (Caucasians, Chinese, South Americans, Carribeans, Middle Easterners, Japanese, and North Africans). DRB1∗01, DRB1∗09, DRB1∗11, DRB1∗12, and DRB1∗16 alleles were protective, in agreement with the type of amino-acidic (aa) residues (ranging from position 9 to 90) included in pockets 1, 4, 6, 7, and 9, which are most involved in peptide presentation. Changes in aa residues affect the capability of HLA molecules in binding myelin peptides. DQB1∗06:02 risk allele seems to be the most interesting target as humanized mice expressing only DQB1∗06:02 develop MS-like disease mediated by autoimmune reactions against myelin oligodendrocytic basic protein that stabilizes the myelin. Our summary of results from a high number of patients and controls suggests that allelic variants from both DQB1 and DRB1 genes are equally involved in MS susceptibility/protection transethnically.

Meta-analysis of FOXP3 gene rs3761548 and rs2232365 polymorphism and multiple sclerosis susceptibility

BACKGROUND

Multiple sclerosis (MS) is a common autoimmune disease of the central nervous system (CNS), and is associated with genetic factors. FOXP3 gene polymorphism has been reported as the risk factor for MS, however, previous studies have showed conflicting results. The purpose of this study is to investigate the association between FOXP3 gene polymorphism and the susceptibility to MS.

METHODS

Pubmed, Embase, library of Cochrane, and Web of Science were used to search the eligible articles from January 1980 up to October 2018. The odds ratio (ORs) and its 95% confidence intervals (CI) were used to evaluate the strength of association. Allele model, homozygote model, heterozygote model, dominant model, and recessive model were used to evaluate the association between FOXP3 gene polymorphism and MS.

RESULTS

A total of 5 studies contained 1276 MS patients and 1447 controls (for rs3761548) and 600 MS patients and 640 controls (for rs2232365) were enrolled in this meta-analysis. The association showed significant differences in allele and dominant model for rs3761548 polymorphism. In addition, a clear tendency to significance was detected in homozygote and recessive model for rs3761548 (P = .052). Subgroup analysis indicated a significant risk of MS in all genotype models but heterozygotes in Asians.

CONCLUSION

FOXP3 gene polymorphism rs3761548 was associated with a higher MS risk, especially in Asians. This conclusion needs to be validated in more large samples and multiracial studies.

LEVEL OF EVIDENCE

Level III diagnostic study.