TNF-alpha, TNF-beta and IL-4 gene polymorphisms in Iranian patients with multiple sclerosis

Anthropometric indices, nutrient intakes and health-related characteristics of patients with multiple sclerosis: a cross-sectional study

BACKGROUND

Multiple sclerosis (MS) is accompanied by many health-related issues. This study aimed to evaluate the anthropometric indices, nutrient intakes and health-related characteristics of MS patients as well as their possible correlations.

METHODS

This cross-sectional study was performed on 283 MS patients in Shiraz, Iran, during 2018-2019. Body mass index (BMI) and body composition were measured for each participant. A food frequency questionnaire was used to determine the patients' nutrient intakes. The level of fatigue, disability and quality of life of the individuals were assessed by the modified fatigue impact scale (MFIS), the expanded disability status scale and the multiple sclerosis quality of life-54 questionnaires, respectively.

RESULTS

The results revealed that 43.11% of the patients were overweight or obese, and their %body fat (%BF) was 35.65 ± 7.63. Besides, intakes of vitamins A, E, D, folic acid, calcium, zinc and magnesium were significantly lower than recommendations in both genders, and sodium intake was significantly higher than the tolerable upper intake level in females. A significant positive linear correlation was observed between MFIS and BMI (r = 0.12, P = 0.045). Significant positive correlations were also found between psychosocial subscale of MFIS and both of %BF (r = 0.12, P = 0.049) and visceral fat area (r = 0.14, P = 0.02). Unexpectedly, the patients' quality of life showed significant negative correlations with fat free mass and skeletal muscle mass.

CONCLUSION

Being overweight, having a high %BF and poor nutrient intakes are common among MS patients. Improving the patients' lifestyle and dietary intake is recommended to reduce fatigue and increase their life quality.

Effect of Carvacrol on histological analysis and expression of genes involved in an animal model of multiple sclerosis

BACKGROUND

The most common non-traumatic neurological disease in young- and middle-aged adults is multiple sclerosis (MS), leading to central nervous system (CNS) atrophy and neurological disorders with loss of myelin and axonal degeneration. Due to the inadequate efficiency of common treatments, some natural products with antioxidant properties such as Carvacrol have been considered.

OBJECTIVE

the present study aimed to investigate carvacrol's anti-inflammatory and therapeutic effects on MS symptoms in healthy and experimental autoimmune encephalomyelitis (EAE) induced female Lewis rats.

METHODS

The study was performed in three groups of Lewis rats: control group, EAE model, and EAE treated with carvacrol (carvacrol-treated group). The treatment group received 25 mg/kg of carvacrol intraperitoneally daily. Histologic examination and expression analysis of pro-inflammatory genes (Interleukin-1 and 17 (IL-1 and IL-17), Nuclear Factor Kappa B Cells (NF-κB) and Tumor Necrosis Factor-α (TNF-α)), myelin repair, and also regeneration genes (Myelin basic protein (MBP), Oligodendrocyte Transcription Factor 2 (OLIG2) and Platelet-Derived Growth Factor Receptor α (PDGFR-α)) were carried out. Gene studies, Hematoxylin and Eosin (H&E), and Luxol fast blue stain were performed in the lumbar region of the spinal cord.

RESULTS

The EAE clinical scores in the carvacrol-treated group were lower than in untreated rats (P < 0.001). The expression of two genes, IL-17 and MBP, was confirmed using fluorescence immunohistochemistry (FIHC). A significant decrease was observed in NF-κB and IL-17, and IL-1 gene expression. The MBP and OLIG2 gene expression was increased in the carvacrol-treated group (p < 0.001). In EAE, PDGFR-α expression increased about four times. However, carvacrol administration did not affect PDGFR-α and TNF-α gene expression. In this treatment, H&E staining of spinal cord regions showed a significant decrease in inflammatory cell infiltration. Moreover, immunostaining analysis demonstrated a considerable increase in MBP and a reduction in IL-17 secretion.

CONCLUSION

The results showed that carvacrol administration reduces the entry of inflammatory cells into the CNS by stimulating myelination-related processes employing increasing the expression of genes involved in myelin repair and reducing the expression of inflammatory genes. Our findings confirm that carvacrol improves the clinical and pathological symptoms of EAE through its therapeutic and modification properties as a potential adjunctive therapy and needs to be studied more.

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.

Reduced Expression of PD-1 in Circulating CD4+ and CD8+ Tregs Is an Early Feature of RRMS

Altered regulatory T cell (Treg) function could contribute to MS. The expression of activating and inhibitory receptors influences the activity of Tregs. Our aim was to investigate T cell phenotypes in relapsing-remitting MS (RRMS) patients at an early phase of the disease. We examined the influence of demographic parameters on the distribution of CD4+ and CD8+ T cell subclasses by generalized linear modeling. We also studied the expression of the following markers-CTLA-4, GITR, PD-1, FoxP3, Helios, CD28, CD62L, CD103-on T cell subsets from peripheral blood with a 14-color flow cytometry panel. We used an antibody array to define the profiles of 34 Th1/Th2/Th17 cytokines in the serum. Expression of PD-1 and GITR on CD4+ and CD8+ Tregs was decreased in RRMS patients. The proinflammatory factors IFN-γ, IL-17, IL-17F, TGFβ-1, TGFβ-3, IL-1SRII, IL-12 p40, sgp130, IL-6sR were significantly increased in RRMS patients. Therefore, a deficiency of PD-1 and GITR immune checkpoints on CD4+ and CD8+ Tregs is a feature of RRMS and might underlie impaired T cell control.

Association of polymorphism -308G/A in tumor necrosis factor-alpha gene (TNF-α) and TNF-α serum levels in patients with relapsing-remitting multiple sclerosis

TNF-α is an important cytokine of the inflammatory response involved in the pathogenesis of relapsing-remitting multiple sclerosis (RRMS). The aim of this study is to explore the association between the promoter polymorphism -308G/A in the TNF-α gene (rs1800629) with genetic susceptibility to RRMS.Methods: A group of 183 RRMS patients and 169 age and gender-matched healthy controls were enrolled in the study. Genotyping of the polymorphism was performed by PCR-restriction fragment length polymorphism and quantification of TNF-α serum levels was conducted by ELISA.Results: The genotype distribution in female patients showed a significantly elevated frequency of heterozygotes (AG) (23.5% vs. 12.8%, OR = 2.072, p = 0.029) in comparison with the healthy women. Substantially higher TNF-α serum levels were observed in females compared to males, in both patients and healthy controls (p < 0.05). According to the genotype, TNF-α levels in the RRMS group were calculated in the following order: for GA/AA genotypes (5.67pg/ml vs. 3.48pg/ml, p = 0.0031) and for GG genotypes (4.58pg/ml vs. 3.52pg/ml, p = 0.00043). Moreover, the carriers of at least one A-allele of -308G/A TNF-α polymorphism (GA+AA) are significantly associated with two fold increased risk for RRMS development (OR = 1.950; p = 0.042) in women in contrast to men as well as associated with early onset of the disease (OR = 2.400; p = 0.021).Conclusion: Our study showed that the level of TNF-α in the serum of patients with RRMS showed a significant association with the -308G/A TNF-α polymorphism and gender dependency.

Necrostatin-1 ameliorates the pathogenesis of experimental autoimmune encephalomyelitis by suppressing apoptosis and necroptosis of oligodendrocyte precursor cells

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system characterized by neuronal demyelination. MS pathogenesis occurs via multiple mechanisms, and is mediated in part by oligodendrocyte apoptosis and a robust inflammatory response. In the present study, Necrostatin-1 (Nec-1), a specific inhibitor of the receptor-interacting protein 1 kinase domain, was revealed to effectively alleviate the severity and pathological damage associated with experimental autoimmune encephalomyelitis (EAE), a commonly used mouse model of MS. In addition, treatment with Nec-1 significantly decreased the number of lesions and inflammatory cell infiltrates in spinal cord tissues, as well as the production of associated pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), interferon-γ and interleukin-1β. Nec-1 also suppressed TNFα + zVAD-fmk-induced apoptosis and necroptosis in primary oligodendrocyte precursor cells. The present study revealed that Nec-1 effectively attenuated the progression of EAE by suppressing apoptosis and necroptosis in oligodendrocytes, and represents a potential novel therapeutic agent for the treatment of MS.

Interleukin-4 -590 T>C and interleukin-4 receptor Q551R A>G gene polymorphisms in Saudi cases with alopecia areata

OBJECTIVES

Immunogenetic factors are known to play a role in the pathogenesis of alopecia areata (AA). This study aimed at investigating the association between AA with the polymorphisms of interleukin-4 (IL-4) promoter and receptor (IL-4R) genes.

PATIENTS AND METHODS

This work is a case-control study that was conducted on 76 AA patients from Qassim region, Saudi Arabia. Patients were compared with 93 normal healthy controls from the same locality. Genomic DNA was extracted and processed using real-time PCR amplification for characterization of IL-4 -590 T>C and IL-4R Q551R A>G gene polymorphisms.

RESULTS

Cases of AA showed a higher frequency of the IL-4 -590 CC homozygous genotype compared with controls (63.2 vs. 53.8%, P>0.05) with a lower frequency of the TT genotype (5.3 vs. 10.8%); yet, both were statistically nonsignificant (P>0.05). Regarding the IL-4R Q551R A>G polymorphism, cases and controls showed nearly equal frequencies of all variants, that is, with no significant difference. Although the frequency of the IL-4 C and the IL-4R A alleles was higher among cases than among controls (78.9 vs. 71.5% and 78.8 vs. 72.6%, respectively), this was also statistically nonsignificant (P>0.05). Comparing case subgroups in terms of their age of onset, sex, disease severity, consanguinity, and family history showed no statistically significant difference regarding the studied genetic variant.

CONCLUSION

IL-4 -590 and IL-4R Q551R gene polymorphisms are not associated with the susceptibility and the clinical pattern of AA in Saudi patients. We recommend further research studies involving the estimation of cytokines both in the serum and in the local skin lesions or in cultured skin cells to figure out whether Th1 or Th2 pathways play a specific role in the pathogenesis of AA.

Association of IL4 and IL4R polymorphisms with multiple sclerosis susceptibility in Caucasian population: A meta-analysis

BACKGROUND

Previous studies have suggested a role for interleukin-4 (IL4) and its receptor (IL4R) gene in susceptibility to multiple sclerosis (MS), but the results remain controversial and under-powered.

OBJECTIVES

To investigate the contradictory results, we performed a meta-analysis to assess the possible association between polymorphisms of the IL4 rs2243250 (C/T), variable number of tandem repeat (VNTR) polymorphism in intron-3 (I3(709)VNTR), IL4R rs1801275 (T/C) and MS in Caucasian populations.

METHODS

A comprehensive search was conducted to identify all case-control or cohort design studies. The fixed or random effect pooled measure was selected based on the homogeneity test among studies that was evaluated with I(2). Publication bias was estimated using the Begg's and Egger's test.

RESULTS

A total of ten studies were included in the meta-analysis. The crude odds ratios (ORs) with 95% confidence intervals (95% CI) were calculated to evaluate the association. Overall, after excluding articles deviating from Hardy-Weinberg equilibrium in controls and sensitive analysis, the meta-analysis showed a significant association between polymorphism of IL4 rs2243250 and MS susceptibility in allele model (OR=1.209, 95% CI=1.022-1.429, P=0.026) and dominant model (OR =1.225, 95% CI=1.013-1.480, P=0.036). However, no significant association was found between polymorphisms of IL4 I3(709)*VNTR, IL4R rs1801275 and MS susceptibility, respectively.

CONCLUSIONS

The meta-analysis indicates that the T allele, CT and TT genotype of polymorphism of IL4 rs2243250 (C/T) may reduce the risk of MS in Caucasian populations, while polymorphisms of IL4 I3(709)*VNTR and IL4R rs1801275 may not associated with risk of MS in Caucasian populations.

Genetic, Immune-Inflammatory, and Oxidative Stress Biomarkers as Predictors for Disability and Disease Progression in Multiple Sclerosis

The aim of this study was to evaluate the TNFβ NcoI polymorphism (rs909253) and immune-inflammatory, oxidative, and nitrosative stress (IO&NS) biomarkers as predictors of disease progression in multiple sclerosis (MS). We included 212 MS patients (150 female, 62 male, mean (±standard deviation (SD)) age = 42.7 ± 13.8 years) and 249 healthy controls (177 female, 72 male, 36.8 ± 11 years). The disability was measured the Expanded Disability Status Scale (EDSS) in 2006 and 2011. We determined the TNFβ NcoI polymorphism and serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-4, IL-10, and IL-17, albumin, ferritin, and plasma levels of lipid hydroperoxides (CL-LOOH), carbonyl protein, advanced oxidation protein products (AOPPs), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter (TRAP). The mean EDSS (±SD) in 2006 was 1.62 ± 2.01 and in 2011 3.16 ± 2.29, and disease duration was 7.34 ± 7.0 years. IL-10, TNF-α, IFN-γ, AOPP, and NOx levels were significantly higher and IL-4 lower in MS patients with a higher 2011 EDSS scores (≥3) as compared with those with EDSS < 3. The actual increases in EDSS from 2006 to 2011 were positively associated with TNF-α and IFN-γ. Increased IFN-γ values were associated with higher pyramidal symptoms and increased IL-6 with sensitive symptoms. Increased carbonyl protein and IL-10 but lowered albumin levels predicted cerebellar symptoms. The TNFB1/B2 genotype decreased risk towards progression of pyramidal symptoms. Treatments with IFN-β and glatiramer acetate significantly reduced TNF-α but did not affect the other IO&NS biomarkers or disease progression. Taken together, IO&NS biomarkers and NcoI TNFβ genotypes predict high disability in MS and are associated with different aspects of disease progression. New drugs to treat MS should also target oxidative stress pathways.

The Impact of IFN-γ Gene Polymorphisms on Spontaneous Clearance of HCV Infection in Fars Province, Southern of Iran

BACKGROUND

Certain polymorphisms in cytokine genes such as IFN-γ may influence the outcome of hepatitis C virus (HCV) infection. Here the frequency of the genotype, allele, and haplotype of IFN-γ gene at some loci is investigated in HCV-infected patients.

METHODS

Totally 255 patients with chronic HCV infection and 44 spontaneously cleared individuals were included. The chronic or clearance states were confirmed using enzyme-linked immunosorbent assay (ELISA) and two different qualitative reverse transcriptase polymerase chain reaction (RT-PCR) techniques. IFN-γ gene polymorphisms were performed by PCR using sequence-specific primers and PCR-RLFP on extracted genomic DNA.

RESULTS

The frequency of GG genotype (P = 0.0001, OR: 5.69 and CI: 2.21-14.62) and allele (P = 0.0003, OR: 2.73 and CI: 1.54-4.83) of IFN-γ gene at +2109 locus was significantly higher in cases that spontaneously cleared the infection. Haplotype analysis showed the association of AG haplotype (P = 0.0046, OR = 6.14 and CI = 1.56-25) with spontaneous clearance of the infection.

CONCLUSION

Our finding indicated that individuals with GG genotype at +2109 loci of IFN-γ gene and also AG haplotype (A allele at +874 loci and G allele at +2109 loci) may clear HCV infection more frequently than those with AA and AG genotype at +2109 loci and AA, TA, and TG haplotype.

Tumor necrosis factor beta NcoI polymorphism is associated with inflammatory and metabolic markers in multiple sclerosis patients

To evaluate the association between the tumor necrosis factor beta (TNF-β) NcoI polymorphism and inflammatory and metabolic markers in patients with multiple sclerosis (MS) patients and the association of these markers with disease disability, a 782 base-pair fragment of the TNF-β gene was amplified from genomic DNA and digested with the NcoI restriction enzyme. The serum levels of numerous cytokines (IL-1β, IL-12, IL-6, TNF-α, IFN-γ, IL-4, IL-10, and IL-17) serum lipid levels, plasma insulin levels, and the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) levels were evaluated in 123 female and 43 male patients with MS. Females carrying the TNFB2/B2 genotype presented with decreased IL-4 and IL-10 levels and increased TNF-α, glucose, insulin, and HOMA-IR levels; moreover, there were positive correlations between EDSS and glucose and between EDSS and HOMA-IR in these females. Males carrying the TNFB2/B2 genotype exhibited increased levels of TNF-α, IFN-γ, and IL-17 (p=0.0326) and decreased levels of IL-4, IL-10, insulin, and HOMA-IR; there was a positive correlation between EDSS and TNF-α levels. The TNFB2/B2 genotype of TNF-β NcoI polymorphism was associated with increased inflammatory and metabolic markers and this association was different according to sex of MS patients.

Relationship between the IL-4 gene promoter -590C/T (rs2243250) polymorphism and susceptibility to autoimmune diseases: a meta-analysis

OBJECTIVE

Studies investigating the association between interleukin (IL)-4 gene promoter -590C/T (rs2243250) polymorphism and autoimmune diseases report conflicting results. To derive a more precise estimation of the relationship, a meta-analysis was performed.

METHODS

A systematic literature search was conducted to identify relevant studies. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to estimate the strength of association.

RESULTS

A total of 6001 cases and 6788 controls from 24 studies were analysed. Significant association of the C allele of IL-4 rs2243250 polymorphism with rheumatoid arthritis (RA) was detected (odds ratio (OR) = 0.696, 95% confidence interval (CI) = 0.601-0.807). Stratification by ethnicity indicated an association between the IL-4 rs2243250 polymorphism and RA in Caucasians. Furthermore, the overall ORs of the associations between the C allele and multiple scleorosis (MS) were 1.340 (95% CI = 1.102-1.630). However, we failed to reveal any association between IL-4 rs2243250 polymorphism and systemic lupus erythematosus (SLE), type 1 diabetes (T1D) or Graves' disease (GD).

CONCLUSIONS

The present study suggests that the IL-4 rs2243250 polymorphism might be associated with genetic susceptibility to autoimmune diseases, including RA and MS.

The Role of Interferon Gamma Gene Polymorphism (+874A/T, +2109A/G, and -183G/T) in Response to Treatment Among Hepatitis C Infected Patients in Fars Province, Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection as a worldwide health problem is associated with cirrhosis and hepatocellular carcinoma. With current treatment regimen, pegylated interferon (PEG-IFN) plus ribavirin, sustain virological response (SVR) is achieved in only 50% of infected individuals. In HCV infection, an inappropriate ratio of cytokines may affect the benefit of antiviral therapy. Given the polymorphisms in regulatory regions of cytokines genes may influence cytokines production.

OBJECTIVES

We aimed to investigate both the frequency of genotypes and alleles of interferon gamma (IFN-γ) gene at +874A/T, +2109A/G, and -183G/T loci in HCV-infected patients and their associations with response to therapy.

PATIENTS AND METHODS

A total of 158 patients were included and treated with PEG-IFN plus ribavirin. The presence of HCV infection in patients was confirmed by reverse transcription polymerase chain reaction, and genomic DNA was extracted from peripheral leukocytes using salting out method. IFN-γ gene polymorphisms were identified by polymerase chain reaction using sequence specific primers and restriction fragment length polymorphism analysis on genomic DNA.

RESULTS

Of 158 patients, 110 (69.5%) subjects achieved SVR and 48 (30.5%) subjects did not respond to therapy. The frequency of AA genotype (P = 0.001; OR: 11.2; CI: 2.26-63.21) and A allele (P = 0.01; OR: 3.23; CI: 1.23 8.56) of IFN-γ gene at +2109 locus were significantly different between the responder and non-responder subjects infected with genotype 1. Regardless of HCV genotype, the frequency of AG genotype was also higher in responder group than those who did not respond to therapy (P = 0.041; OR: 05.05; CI: 1.05-33.25)). In case of IFN-γ gene at +874 locus, there was no difference in genotypes and alleles frequencies between the responder and non-responder subjects infected with HCV genotypes 1 and 3. Haplotype analysis showed no association between haplotypes and response to therapy. All participants had G/T genotype at -183 locus.

CONCLUSIONS

Our findings indicate that heterogeneity at +2109 locus of IFN-γ gene but not at +874 locus could interfere with successful therapy in patients infected with HCV genotype 1.

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.

Cytokine profile in relapsing‑remitting multiple sclerosis patients and the association between progression and activity of the disease

Multiple sclerosis (MS) is a progressive immune‑ mediated disease caused by demyelination of the central nervous system. Cytokines and their receptors have an important role in the evolution of MS lesions, and pro‑ and anti‑inflammatory cytokine levels have been found to correlate with changes in MS disease activity. The aims of the present study were to evaluate the pro‑inflammatory [tumor necrosis factor (TNF)‑α and interleukin (IL) ‑1β, ‑6 and ‑12], T helper (Th) 1 [interferon (IFN)‑γ], Th17 (IL‑17) and Th2 (IL‑4 and ‑10) cytokine serum levels in relapsing‑remitting (RR)‑MS patients and to evaluate the association between the cytokine profile and the progression and activity of the disease. Serum cytokine levels were assessed using enzyme linked‑immunosorbent assays in 169 RR‑MS patients in the remission clinical phase and 132 healthy individuals who were age‑, gender‑, ethnicity‑ and body mass index‑matched. Disability and activity of the disease were evaluated using the Expanded Disability Status Scale and magnetic resonance imaging with gadolinium, respectively. IFN‑γ and IL‑6, ‑12 and ‑4 levels were higher in RR‑MS patients compared to controls (P=0.0009, 0.0114, 0.0297 and 0.0004, respectively). IL‑1 levels were higher in controls compared with RR‑MS patients. IL‑4 levels were higher in RR‑MS patients with mild disability compared to those with moderate and severe disability (P=0.0375). TNF‑α and IL‑10 levels were higher in RR‑MS patients with inactive disease compared with those with active disease. IL‑17 levels showed a trend towards being higher in RR‑MS patients with inactive disease compared to those with active disease (P=0.0631). Low TNF‑α and high IFN‑γ levels were independently associated with RR‑MS (P=0.0078 and 0.0056, respectively) and also with the activity of the disease (P=0.0348 and 0.0133, respectively). Results indicated that RR‑MS patients, even in the remission clinical phase, exhibit a complex system of inflammatory and anti‑inflammatory cytokines that may interact to modulate the progression and activity of the disease.

Fractalkine gene receptor polymorphism in patients with multiple sclerosis

BACKGROUND

Although the immunopathogenesis of multiple sclerosis (MS) has been intensely investigated in recent years, some associated molecules still have not been examined. For instance, no study has been conducted to investigate a possible polymorphism in the fractalkine receptor gene.

METHODS

In order to examine fractalkine gene receptor polymorphisms, 3 mL of serum from 92 MS patients and 91 controls were stored at -20°C. DNA was extracted from the serum samples that were purified, and the gene regions in CX3CR1 (i.e., the fractalkine regions) containing the T280M and V294I fractalkine receptor haplotypes were amplified via the polymerase chain reaction (PCR) technique. The obtained fragments were then cut using restriction enzymes, and agarose gel electrophoresis was performed.

RESULTS

In a comparison of the patients and controls, we found that the median values of the Expanded Disability Status Scale (EDSS) scores among genotypes of the V294I polymorphism in the fractalkine gene receptor were statistically higher in genotype II than genotype VI. Also, relapsing/remitting MS (RRMS) was statistically higher in genotype VI than in genotype II, whereas the frequency of secondary progressive MS (SPMS) was statistically higher in genotype VV than in the genotype VI for the same polymorphism.

CONCLUSIONS

Although many polymorphism studies have focused on patients with MS, there is no polymorphism study about the fractalkine receptor which is a chemokine and plays an important role in neuroinflammation and neurodegeneration. Our results provide information about disease progression and may also be beneficial in developing new strategies for the treatment of the disease.

Association of interleukin 4 (-590 T/C) and interleukin 4 receptor (Q551R A/G) gene polymorphisms with acne vulgaris

BACKGROUND AND OBJECTIVES

Acne vulgaris is a common skin disorder. The complete etiology of this disease remains to be identified; however, it seems that aberrant expression of cytokine genes might be a contributing factor. This study aimed to investigate the association of genetic polymorphisms related to interleukin 4 (IL-4) promotor and receptor (IL-4R) genes as inflammatory modulators with acne vulgaris.

DESIGN AND SETTING

A case-control study 95 acne patients recruited from outpatient dermatology clinics affiliated with Qassim University, Qassim, Saudi Arabia.

PATIENTS AND METHODS

Acne patient data were compared with 87 normal healthy unrelated controls from the same locality. The genomic DNA was extracted and processed using the real-time polymerase chain reaction amplification for characterization of polymorphisms related to IL-4 (-590 T/C) and IL-4R (Q551R A/G) genes.

RESULTS

Acne patients compared to controls showed no significant difference in the frequencies of IL-4 (-590 T/C) polymorphic genotypes (P=.8), yet had a highly significant difference in IL-4R (Q551R A/G) genotypes (P<.001). The frequencies of the mutant genotype IL-4R GG as well as the allele IL-4R G were significantly higher in cases of acne than in controls. Furthermore, acne cases showed higher frequencies of combined genotypes IL4R_GG with IL-4_CC, CT, or TT. However, no significant difference was noted on comparing subgroups related to disease severity or response to treatment (P>.05).

CONCLUSIONS

This study provides evidence for a significant association of IL-4R (Q551R A/G) genetic polymorphisms with the susceptibility rather than the severity of acne vulgaris.

Association of interleukin-4 polymorphisms with multiple sclerosis in southeastern Iranian patients

BACKGROUND AND OBJECTIVES

Immune system-related factors are important in the pathogenesis of multiple sclerosis (MS). Interleukin 4 (IL-4) as a helper T cell (2TH) cytokine is involved in the regulation of immune responses. Hence, this study was designed to explore the association between MS and polymorphisms in the -590 region of IL-4.

DESIGN AND SETTING

A descriptive study at Rafsanjan University of Medical Sciences, Rafsnajan from September 2009 to August 2010.

PATIENTS AND METHODS

Blood samples were collected from 100 MS patients and 150 healthy controls on EDTA precoated tubes. DNA was extracted and analyzed for IL-4 polymorphisms using restricted fragment length polymorphism in patients and controls. Demographic data were also collected by a questionnaire that was designed specifically for this study.

RESULTS

We observed a significant difference in the C/C, T/C, and T/T genotypes of the -590 region of IL-4 between patients with MS and healthy controls (P<.001).

CONCLUSIONS

We conclude that functional polymorphisms of IL-4 possibly play a crucial role in the pathogenesis of MS.

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

Multiple sclerosis is a multifactorial disorder with complex genetic basis. It is believed that genes encoding HLA molecule and cytokines are involved in the pathogenesis of MS. In this study, we have evaluated the impact of HLA-DRB1*1501 allele and TNF-alpha -308 G/A single nucleotide polymorphism, and their interaction, in the susceptibility to MS in Iranian population. Genomic DNA samples were prepared from whole blood of 366 MS Patients and 414 control subjects. The genotypes were determined by SSP-PCR method. Frequency of alleles and genotypes were compared between the two groups by using Fisher's exact test. HLA-DRB1*1501 allele was more frequent among patients (OR=1.57, P=0.0026). TNF-α -308 G allele and G/G genotype had higher frequency among MS patients than control subjects (G vs. A: OR=1.26, P<0.05); G/G vs. A/A: OR=4.59, P=0.0003). The odds ratio was higher among HLA-DRB1*1501 positive individuals. Co-existence of TNF G and HLA-DRB1*1501 alleles showed higher prevalence among MS patients (OR=7.07, P=0.0007). Our results have shown that HLA-DRB1*1501 allele and TNF-α -308 G/A polymorphism are associated with the risk of multiple sclerosis in Iranian population. We also observed an interaction between these two loci that support the role of HLA alleles and cytokine genes and gene-gene interaction in the development and pathogenesis of MS.

-308 G > A of TNF-α gene promoter decreases the risk of multiple sclerosis: a meta-analysis

BACKGROUND

Environmental and genetic factors are thought to be involved in the pathogenesis of multiple sclerosis (MS). Polymorphisms of tumor necrosis factor (TNF)-α -308 were implicated in MS risk in several case-control association studies. However, the studies have shown inconsistent results.

OBJECTIVES

To address the association of G/A polymorphisms of TNF-α -308 with MS risk by meta-analysis.

METHODS

Thirteen studies were included. Pooled odds ratios (ORs) together with 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 1870 cases and 2769 controls were included in the meta-analysis. The pooled result indicated that -308 A allele is significantly associated with reduced risk of MS compared with -308 G allele (A vs. G, p=0.022). The same pattern of the result was also obtained in the contrasts of AA+ GA vs. GG (p=0.008) and GA vs. GG (p=0.007). For AA vs. GG or AA vs. GA + GG, no significant association was detected most likely caused by very low frequency or non-availability of homozygote genotype AA for all of the studies.

CONCLUSIONS

TNF-α -308 A allele is associated with reduced risk of MS.

TNF-alpha promoter polymorphisms in multiple sclerosis: no association with -308 and -238 alleles, but the -857 alleles in associated with the disease in Turkish patients

Dysregulation in the expression of pro- and anti-inflammatory cytokines is one of the milestones in multiple sclerosis (MS) development and progression. Tumour necrosis factor (TNF-alpha), a proinflammatory cytokine is believed to play an important role in MS pathogenesis. The objective of this study is to investigate the association between TNF-alpha promoter region (TNF-alpha-238, -308 and -857) and susceptibility to MS and clinical course of the disease. Eighty-six relapsing remitting MS patients and 150 sex-, age- and ethnic-matched controls were enrolled in the study. Genotyping was performed by PCR-RFLP method. We observed a statistically significant increase in TNF-alpha 857 CC genotype in MS patients than controls (P < 0.001) while TNF-alpha 857 CT genotype showed a significant negative correlation with MS patients (P = 0.033). No differences in the distribution of the TNF-alpha-238 and -308 alleles were observed. None of the three polymorphisms (-238, -308 and -857) did not show relation with disease duration, Expanded Disability Status Scale or age of onset. On the other hand, significant difference of TNF -857 CC genotype was identified with the low disease index (P = 0.025). Although the study group is small, the results indicate that TNF-alpha 857 CC genotype may cause susceptibility to MS in the Turkish population.

CTLA4 exon 1 and promoter polymorphisms in patients with multiple sclerosis

OBJECTIVE

The polymorphisms of exon 1 (+49 A/G) and promoter regions (-1722 T/C, -1661 A/G and -318 C/T)of cytotoxic T lymphocyte antigen 4 (CTLA4) and also haplotypes constructed from mentioned loci were investigated amongst 153 Iranian patients with definite multiple sclerosis (MS) and 190 healthy controls.

METHODS

The polymorphisms were genotyped by PCR-restriction fragment length polymorphisms and PCR-amplification refractory mutation system. The 4-locus haplotypes were estimated by Arlequin software (University of Berne, Berne, Switzerland).

RESULTS

Preliminary results showed significant increase of +49 G allele and -1661 AG genotype, as well as TGCA haplotype among patients than controls (P < 0.036, P = 0.009 and P < 0.010, respectively). The distribution of -1722 T/C, -1661 A/G, -318 C/T and +49 A/G (TACA) haplotype, from the contrary, was observed to be significantly increased among controls (P < 0.001).

CONCLUSIONS

After Bonferroni correction, the results provide preliminary evidence that CTLA4 genetic variation at -1661 locus may render Iranian individuals to be more susceptible to MS, whereas harboring TACA haplotype might be protective.

Tumour necrosis factor alpha gene (TNF-alpha) -376 polymorphism in Hungarian patients with primary progressive multiple sclerosis

Tumour necrosis factor alpha (TNF-alpha) is associated with clinical activity in relapsing-remitting multiple sclerosis (RRMS) and the development of progressive disease. Our aim was to investigate the TNF-alpha -376 polymorphism in primary progressive MS (PPMS) patients. Polymerase chain reaction and restriction fragment length polymorphism were carried out on 45 PPMS patients, 45 age and sex-matched RRMS patients and 45 healthy controls (HC). The GG genotype and the guanine allele (G) were detected significantly more often in the PPMS group as compared with the HC group (p=0.027; p=0.032). The G allele may be one of the factors responsible for progression in PPMS.

The genetics of clinical outcome in multiple sclerosis

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system (CNS), the clinical course of which varies considerably between patients. Genetic complexity and interactions with as yet unknown environmental factors have hindered researchers from fully elucidating the aetiology of the disease. In addition to influencing disease susceptibility, epidemiological evidence suggests that genetic factors may affect phenotypic expression of the disease. Genes that affect clinical outcome may be more effective therapeutic targets than those which determine susceptibility. We present in this review a comprehensive survey of the genes (both MHC- and non-MHC-related) that have been investigated for their role in disease outcome in MS. Recent studies implicating the role of the genotype and epistatic interactions in the MHC in determining outcome are highlighted.

Recent advances in genetic analysis of multiple sclerosis: genetic associations and therapeutic implications

Epidemiological studies have confirmed that genetic factors are a key component in the pathogenesis of multiple sclerosis (MS) and that those determining MS susceptibility have been extensively studied. Many papers have been published regarding the heritable differences useful in genetic studies; these include variations in DNA, such as single-nucleotide polymorphisms, microsatellites and insertion/deletion polymorphisms. However, to date, among other regions, HLA is the only region confirmed to possess genes that determine MS susceptibility. In this article, we review the progress during the last 5 years in the studies on the susceptibility genes and the pharmacogenetics of MS. Newer techniques and methods of analysis will hopefully result in better screening of individuals who are at highest risk and novel treatments.