Interaction of HLA-DRB1*1501 allele and TNF-alpha -308 G/A single nucleotide polymorphism in the susceptibility to multiple sclerosis

Prevalence and disease disability in immigrants with multiple sclerosis in Malmö, southern Sweden

BACKGROUND

Multiple sclerosis (MS) is the most common chronic demyelinating disease of the central nervous system and the major non-traumatic cause of permanent disability in young adults. Several migration studies have been performed over the years suggesting a pattern of higher disease disability in certain ethnic groups. To our knowledge, differences in disease progression in immigrants have not been studied in Sweden before. Thus, the aims of our study were to estimate the prevalence of multiple sclerosis among first-generation immigrants in the City of Malmö and to compare differences in disease severity with the native population.

METHODS

All persons with multiple sclerosis living in Malmö on prevalence day 31 Dec 2010 were included. Cases were classified according to the country of birth into Scandinavians, Western and non-Western.

RESULTS

The crude prevalence was 100/100,000 (95% CI, 80-124) among first-generation immigrants, 154/100,000 (95% CI, 137-173) among individuals with Scandinavian background, 123/100,000 (95% CI, 94-162) in the Western group and 76/100,000 (95% CI, 53-108) in the non-Western group. The mean Multiple Sclerosis Severity Score (MSSS) value among Scandinavians was 4.2 (SD 3.5), whereas the figures in the immigrant group were 4.6 (SD 3.3) and 5.2 (SD 3.7) among Westerns respectively non-Westerns, which differences were not statistically significant. When adjusting for gender, age at onset and initial disease course, the mean MSSS difference between the non-Western and the Scandinavian individuals was 1.7 (95% CI 0.18-3.3, p = 0.030). There were no differences on time to diagnosis or the time from diagnosis to treatment initiation between the three groups.

CONCLUSIONS

We found a lower prevalence among Western and non-Western first-generation immigrants compared to the Scandinavian population and a more severe disease in non-Western immigrants than in Scandinavians.

Lack of association between TNFA and TNFB polymorphisms and the risk of multiple sclerosis: a meta-analysis from 37 studies

BACKGROUND

Epidemiological studies about the association between genetic polymorphisms in TNFA, TNFB, and IFNG and the risk for multiple sclerosis (MS) have been performed extensively. However, the results are inconclusive. The purpose of this meta-analysis was to evaluate the contribution of the polymorphisms in TNFA, TNFB, and IFNG to the susceptibility of MS.

METHODS

The PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched to identify relevant studies up to October 2021. A meta-analysis was performed and pooled odds ratios (OR) and confidence intervals (CI) were computed using fixed or random effects models.

RESULTS

A marginally significant association of the IFNG +874AT genotype with high risk of MS was observed in a heterozygous comparison (OR = 1.51, 95% CI, 1.02-2.23). However, no significant association between the TNFA (-308G/A, -238G/A, and -376G/A) and TNFB +252A/G polymorphisms and MS risk was observed both in overall analysis and in subgroup analysis.

CONCLUSION

This meta-analysis provides evidence that the TNFA (-308G/A, -238G/A, and -376G/A) and TNFB +252A/G polymorphisms were not risk factors for the occurrence of MS. Further studies with larger samples are necessary to reach the concise results about the contribution of other polymorphisms to the risk of MS.

Genetic and Molecular Biology of Multiple Sclerosis Among Iranian Patients: An Overview

Multiple sclerosis (MS) is one if the common types of autoimmune disorders in developed countries. Various environmental and genetic factors are associated with initiation and progression of MS. It is believed that the life style changes can be one of the main environmental risk factors. The environmental factors are widely studied and reported, whereas minority of reports have considered the role of genetic factors in biology of MS. Although Iran is a low-risk country in the case of MS prevalence, it has been shown that there was a dramatically rising trend of MS prevalence among Iranian population during recent decades. Therefore, it is required to assess the probable MS risk factors in Iran. In the present study, we summarized all of the reported genes until now which have been associated with MS susceptibility among Iranian patients. To clarify the probable molecular biology of MS progression, we categorized these reported genes based on their cellular functions. This review paves the way of introducing a specific population-based diagnostic panel of genetic markers among the Iranian population for the first time in the world.

Changing epidemiology of immune-mediated inflammatory diseases in immigrants: A systematic review of population-based studies

BACKGROUND

Immune-mediated inflammatory diseases (IMIDs) are systemic diseases of multifactorial etiology that share aberrant immune responses as the common final pathway. With rising globalization, their incidence is increasing in developing countries and among immigrants. Our primary objective was to systematically review the epidemiology of IMIDs in immigrants and conduct a meta-analysis to estimate the risk of IMIDs in immigrant populations according to their origin and destination countries.

METHODS

We systematically searched five biomedical databases and reviewed population-based studies, from inception through August 2018, that reported incidence or prevalence data of inflammatory bowel disease (IBD), multiple sclerosis (MS), type 1 diabetes (T1D), systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ankylosing spondylitis (AS) or psoriasis and psoriatic arthritis (PPA) among immigrants and the host population.

RESULTS

The incidence and prevalence of IMIDs among immigrants differ from host populations, and evolve over subsequent generations. The risk of IBD among immigrants approximates that in hosts, especially among South Asians, with ulcerative colitis incidence changing prior to Crohn's disease incidence. MS risk is highest in Iranian immigrants, T1D in African immigrants and SLE in African and Iraqi immigrants. Data on other IMIDs are sparse. Significant heterogeneity between the studies precluded meta-analysis.

CONCLUSION

Based on our systematic review, the epidemiology of IMIDs among immigrants varies according to native and host countries, immigrant generation, and IMID type. The rapid evolution suggests a role for non-genetic factors and gene-environment interactions. Future studies should focus on these pattern shifts, given implications of rising global burden of IMIDs and immigration.

Combination of interleukin-10 gene promoter polymorphisms with HLA-DRB1*15 allele is associated with multiple sclerosis

BACKGROUND & OBJECTIVES

Multiple sclerosis (MS) is common in some ethnic groups. Interleukin-10 (IL-10) is a potent anti-inflammatory and immunosuppressive cytokine that may be an important regulator in MS disease pathogenesis. IL-10 promoter includes several single nucleotide polymorphisms and the level of IL-10 expression is related to these polymorphisms. Furthermore, loci within the histocompatibility regions are responsible for susceptibility to MS. The aim of this study was to investigate the association of IL-10 gene promoter polymorphisms and HLA-DRB1*15 allele frequencies with MS susceptibility in an Iranian population.

METHODS

In this study 336 MS patients and 454 healthy controls were included. Genomic DNA was purified from peripheral blood samples by a standard protocol. Genotyping was performed by the sequence-specific primer polymerase chain reaction method.

RESULTS

IL-10 -1082 G/G and IL-10 -819 C/C genotypes were more frequent in MS patients than healthy individuals. DRB1*15 allele showed a higher frequency among MS patients compared to controls.

INTERPRETATION & CONCLUSIONS

The IL-10 and HLA-DRB1*15 polymorphisms were associated with the susceptibility to MS in Iranian patients. Our results suggest that gene-gene interaction of IL-10 polymorphisms and HLA-DRB1*15 alleles may be important factors in the development of MS.

Human Epistatic Interaction Controls IL7R Splicing and Increases Multiple Sclerosis Risk

Multiple sclerosis (MS) is an autoimmune disorder where T cells attack neurons in the central nervous system (CNS) leading to demyelination and neurological deficits. A driver of increased MS risk is the soluble form of the interleukin-7 receptor alpha chain gene (sIL7R) produced by alternative splicing of IL7R exon 6. Here, we identified the RNA helicase DDX39B as a potent activator of this exon and consequently a repressor of sIL7R, and we found strong genetic association of DDX39B with MS risk. Indeed, we showed that a genetic variant in the 5' UTR of DDX39B reduces translation of DDX39B mRNAs and increases MS risk. Importantly, this DDX39B variant showed strong genetic and functional epistasis with allelic variants in IL7R exon 6. This study establishes the occurrence of biological epistasis in humans and provides mechanistic insight into the regulation of IL7R exon 6 splicing and its impact on MS risk.

Association of EVI5 rs11808092, CD58 rs2300747, and CIITA rs3087456 polymorphisms with multiple sclerosis risk: A meta-analysis

Purpose

Multiple sclerosis (MS) is a major demyelinating disease of the central nervous system with a strong genetic component. Previous studies have reported that the association of EVI5 rs11808092, CD58 rs2300747, and CIITA rs3087456 polymorphisms with the susceptibility to MS. However, the results were inconsistent. Thus, we conducted this meta-analysis to provide a more accurate estimation of the association between any of these polymorphisms and MS risk.

Methods

The PubMed, Embase, Chinese National Knowledge Infrastructure, Wan Fang databases and MSGene were used to search all potentially relevant studies. The odds ratio (OR) with 95% confidence interval (CI) was used to investigate the associations between these three polymorphisms and MS risk.

Results

16 independent case–control studies from 12 publications were finally included into this meta-analysis. The results showed that EVI5 rs11808092 polymorphism was related with increasing the development of MS under five genetic models (allelic: OR = 1.17, 95% CI = 1.10–1.24, P < 0.01; homozygous: OR = 1.37, 95% CI = 1.18–1.59, P < 0.01; heterozygous: OR = 1.16, 95% CI = 1.07–1.26, P < 0.01; recessive: OR = 1.28, 95% CI = 1.11–1.48, P < 0.01; and dominant: OR = 1.19, 95% CI = 1.11–1.48, P < 0.01). CD58 rs2300747 polymorphism was found to be associated with decreasing MS risk in three genetic models (allelic: OR = 0.86, 95% CI = 0.78–0.94, P < 0.01; heterozygous: OR = 0.85, 95% CI = 0.76–0.94, P < 0.01, and dominant: OR = 0.84, 95% CI = 0.76–0.93, P < 0.01). However, this meta-analysis indicated that CIITA rs3087456 polymorphism was not related to multiple sclerosis.

Conclusions

The mutant alleles of EVI5 rs11808092 polymorphism may increase the susceptibility to MS while those of CD58 rs2300747 polymorphism may decrease MS risk. In addition, CIITA rs3087456 polymorphism might not be associated with MS.

Multiple sclerosis in the Iranian immigrant population of BC, Canada: prevalence and risk factors

Background:

There is a well-documented increase in the risk of multiple sclerosis (MS) when migrating from a region of low prevalence to one of high prevalence.

Objective:

We present here an investigation of MS prevalence and candidate environmental and genetic risk factors among Iranian immigrants to British Columbia (BC), Canada.

Methods:

MS cases of Iranian ancestry were ascertained from a population-based Canadian study. We collected blood samples for genetic and serological analyses, and administered a personal history questionnaire to the cases.

Results:

The crude prevalence of MS in this population of Iranian ancestry was 287/100,000 (95% CI: 229 – 356/100,000). MS cases were more likely to have a history of infectious mononucleosis (odds ratio (OR) = 7.5; p = 0.005) and smoking (OR = 17.0; p < 0.0001), as compared to healthy controls from previous studies in Iran. Cases were also more likely than controls to have been born between April and September (OR = 2.1; p = 0.019).

Conclusion:

The prevalence of MS among Iranian immigrants to Canada is greater than the overall prevalence of MS in Iran by a factor of at least four, and is similar to that recently observed among Iranian immigrants in other western nations. No major genetic susceptibility variants were identified, suggesting the environment in Canada may be what is increasing the risk of MS in this population.

Interaction of HLA-DRB1*1501 and TNF-Alpha in a Population-based Case-control Study of Multiple Sclerosis

This study was conducted to determine whether single nucleotide polymorphisms (SNPs) in nine genes (human leukocyte antigen (HLA), T cell receptor beta (TCA receptor β), tumor necrosis factor α (TNF α), tumor necrosis factor β (TNF β), apolipoprotein E (APOE), interleukin 7 receptor alpha chain (IL7RA) interleukin 2 receptor alpha chain (IL2RA) myelin basic protein (MBP) and vitamin D receptor (VDR)) associated with multiple sclerosis (MS) could be replicated in a population-based sample, and to determine if these associations are modified by presence of HLA DRB1*1501. DNA was available from 722 individuals (223 with MS and 499 controls) who participated in a population-based case-control study. Cases and controls were matched on ancestry, age, gender and geographic area. HLA DRB1*1501 risk allele (T) was confirmed in this population using a genotypic test, controlling for multiple comparisons. Examining the effect of each SNP in the presence or absence of the HLA DRB1*1501 risk allele identified significant associations with TNF α -1031 (rs1799964) among those without the HLA risk allele. No additional interactions were significant in a cases-only analysis. Our results indicate that an interaction between SNPs in TNF α and HLA DRB1*1501 may influence the risk of developing MS.

HLA-DQ strikes again: genome-wide association study further confirms HLA-DQ in the diagnosis of asthma among adults

BACKGROUND

Asthma is a common chronic respiratory disease in children and adults. An important genetic component to asthma susceptibility has long been recognized, most recently through the identification of several genes (e.g., ORMDL3, PDE4D, HLA-DQ, and TLE4) via genome-wide association studies.

OBJECTIVE

To identify genetic variants associated with asthma affection status using genome-wide association data.

METHODS

We describe results from a genome-wide association study on asthma performed in 3855 subjects using a panel of 455 089 single nucleotide polymorphisms (SNPs).

RESULT

The genome-wide association study resulted in the prioritization of 33 variants for immediate follow-up in a multi-staged replication effort. Of these, a common polymorphism (rs9272346) localizing to within 1 Kb of HLA-DQA1 (chromosome 6p21.3) was associated with asthma in adults (P-value = 2.2E-08) with consistent evidence in the more heterogeneous group of adults and children (P-value = 1.0E-04). Moreover, some genes identified in prior asthma GWAS were nominally associated with asthma in our populations.

CONCLUSION

Overall, our findings further replicate the HLA-DQ region in the pathogenesis of asthma. HLA-DQA1 is the fourth member of the HLA family found to be associated with asthma, in addition to the previously identified HLA-DRA, HLA-DQB1 and HLA-DQA2.

A nationwide survey of the prevalence of multiple sclerosis in immigrant populations of Sweden

BACKGROUND

In 2008, immigrants constituted 14% of the population of Sweden, a high-risk area for multiple sclerosis (MS). We investigated the largest Swedish immigrant populations for the prevalence of MS.

METHOD

Data on foreign-born MS patients were retrieved from Swedish national health and population registers. We calculated observed versus expected numbers of MS patients and gender- and age-specific prevalence ratios (PR) between immigrant populations and the general population of Sweden and, where possible, of the countries of birth.

RESULTS

The 19 largest immigrant populations included 1327 MS patients. The global variation in MS prevalence was reflected in Sweden. The prevalence in immigrant populations who had moved to Sweden from countries with a lower MS risk was however higher than in their countries of birth. Notably, the MS prevalence in the population born in Iran was at least as high as in the general population of Sweden (men: PR = 1.10, 95% CI 0.81-1.46, p = 0.537, women: PR = 1.18, 95% CI 0.97-1.44, p = 0.855) and more than twice as high as in Isfahan, Iran (men: PR = 3.06 (95% CI 2.26-4.06), p <0.001, women: PR = 2.21 (95% CI 1.81-2.68), p <0.001).

CONCLUSIONS

The MS prevalence increased in migrants who moved to Sweden from countries with a lower MS risk. In the Iranian immigrant population the prevalence exceeded that in the general population of Sweden. This indicates that Iranians carry genetic factors that contribute to a higher MS risk when environmental-lifestyle MS risk factors change.