An association of interleukin-10 gene polymorphisms with Graves' disease in two Chinese populations

Molecular analysis of interleukin-10 gene polymorphisms in patients with Behçet's disease

BACKGROUND

Interleukin 10 (IL-10) is a cytokine with potent anti-inflammatory properties that play a fundamental role in restrictive host immune response to pathogens, by means of that is a crucial importance for chronic inflammatory disease studies. Therefore, the goal of this study was to measure the correlation of the IL-10 gene polymorphisms with the susceptibility to Behçet's disease compared with the control group in the Azeri population and to determine the expression of this gene in the two groups. Also, real-time PCR was performed for evaluate the IL-10 mRNA expression of the associated polymorphisms.

METHODS

In this study, blood samples from 47 (1 missed) patients and 58 (3 missed) healthy control were taken, and then mononuclear cells isolated with ficoll protocol. The DNA and RNA were subsequently extracted. They were examined for -592A/C (rs1800872) of IL-10 gene single nucleotide polymorphism (SNP) using RFLP-PCR. Allele and genotype distributions were evaluated among groups using chi-square or Fisher's test. Following this, the extracted RNA was converted to cDNA using the RT-PCR method, after that expression of IL-10 evaluated by Real-time PCR. Serum levels of IL-10 were measured using Enzyme-linked immunosorbent assay (ELISA).

RESULTS

Rates of the rs1800872 A allele was statistically lower in the control group compared with BD patients (p = 0.0315 and OR = 1.90 (1.05-3.42)). Also, as we expected, the expression level of the IL-10 gene was seen to significantly decrease in the patient group compared to the control.

CONCLUSIONS

Our study showed that the rs1800872 A allele of the IL-10 gene may contribute to the genetic susceptibility of BD by regulating the expression of IL-10. Also as we expected, the expression level of this gene was seen to significantly decrease in the patient group compared to the control.

Association between polymorphism within interleukin related genes and Graves' disease: a meta-analysis of 22 case-control studies

Graves' disease (GD) is a common autoimmune disorder with a genetic predisposition. There is strong evidence to suggest that both Th1 and Th2 circulating cytokines are involved in the development of GD. In this study, we conducted a meta-analysis to assess the impact of seven variations of five IL-related genes on the susceptibility to GD. A total of 22 case-control studies involving 5338 GD patients and 6446 healthy controls were included. The results showed that only one SNP rs1800795 in IL-6 was significantly associated with GD in homozygous model (CC vs. GG: OR = 2.714, 95% CI = 1.047-7.039, p = 0.04), heterozygous model (CG vs. GG: OR = 1.295, 95% CI = 1.013-1.655, p = 0.039), dominant model (CC+CG vs. GG: OR = 1.418, 95% CI = 1.122-1.793, p = 0.003) and additive model (C vs. G: OR = 1.432, 95% CI = 1.087-1.886, p = 0.011).To explain the heterogeneity, we performed the subgroup analysis by ethnicity. The ethnicity stratification revealed that the association between rs1800795 and GD tended to be much stronger for Asian than European population in homozygous, dominant, recessive, and additive models. The remaining 6 SNPs in 4 genes did not show any significant association with GD in any genetic models. Together, our data support that rs1800795 within the IL-6 gene confers genetic susceptibility for GD. Future large-scale studies are required to validate the associations between IL-6 and others IL-related genes and GD.

Association of Interleukin 10 Gene Polymorphisms with Autoimmune Thyroid Disease: Meta-Analysis

The aim of this study was to perform a meta-analysis of eligible studies and to derive a precise estimate of the association between interleukin 10 (IL10) polymorphisms and susceptibility to autoimmune thyroid disease (AITD). Meta-analyses were conducted on the associations between AITD and the -1082 G/A (rs1800896), -819 C/T (rs1800871) and -592 C/A (rs1800872) polymorphisms in IL10, and the haplotype of these polymorphisms and AITD. A total of 2903 AITD patients and 3060 controls in 10 eligible studies were included in the meta-analysis. This meta-analysis showed significant associations between IL10 at the -1082 G allele and overall AITD (OR: 1.44, 95% CI 1.13-1.82, P = 0.003), but no association between the IL10 -592 C allele and the -819 C allele and AITD. Subgroup studies demonstrated significant associations between the -1082 G allele and susceptibility to Graves' disease. Ethnicity-specific meta-analysis revealed significant associations between the -1082 G allele and AITD susceptibility in Asian populations; however, in Middle Eastern populations, no association was evident. Meta-analysis of the IL10 haplotype revealed an association between the ATA haplotype and AITD (OR: 1.17, 95% CI 1.00-1.36, P = 0.04). Meta-analysis demonstrates that the IL10 polymorphisms are associated with susceptibility to AITD.

Comprehensive analysis of cytokine gene polymorphisms defines the association of IL-12 gene with ophthalmopthy in Korean children with autoimmune thyroid disease

In early onset autoimmune thyroid disease (AITD) showing a strong genetic tendency, cytokines have been suggested to play a critical role in the development of AITD. To directly compare the influences of several cytokine gene polymorphisms, 25 single nucleotide polymorphisms (SNPs) in 17 cytokine genes were analyzed on 104 Korean children with AITD [Hashimoto's disease (HD) = 44, Graves' disease (GD) = 60 (thyroid-associated ophthalmopathy (TAO) = 29, non-TAO = 31)] and 192 controls. Compared with healthy controls, any significant association with polymorphisms of cytokine genes was not found in HD and GD. Among GD patients, non-TAO group only showed significant associations with IL-12 C allele (rs3212227: A > C) (76.6% vs. 51.6%, OR = 0.3 [0.15-0.71], Pc = 0.007). Particularly, the frequency of IL-12C allele was significantly lower in the non-TAO group than in the TAO group (82.8% vs. 51.6%, Pc = 0.018). Our comprehensive analysis of cytokine gene polymorphisms suggests that IL-12 gene may play impact on specific pathogenesis of ophthalmopathy in Korean children with AITD.

The association of SCGB3A2 polymorphisms with the risk of Graves' disease: a meta-analysis

The aim of this study is to assess the association of the SCGB3A2 -112G>A promoter polymorphism with Graves' disease(GD) using a meta-analysis. Relevant studies were identified using PubMed and EMBASE electronic databases. A meta-analysis of relevant studies was performed. This meta-analysis included four case-control studies, containing 6,913 GD cases (Caucasian 3904, Han 3009) and 7,185 controls(Caucasian 4155, Han 3030). The combined results showed a significant difference in genotype distribution (-112A/G) between GD and control populations (A vs. G P = 1.53 × 10(-7); GG vs. AA+AG P = 6.78 × 10(-9)). Meta-analysis was performed using a fixed-effects model. Under the dominant model (GG/AA + GA), the AA and GA genotypes were significantly associated with GD (pooled OR = 1.24, 95 % CI 1.12-1.37). When the two European studies are combined, the AA and GA genotypes were also significantly associated with GD (pooled OR = 1.29, 95 % CI 1.20-1.39). This meta-analysis suggests that SCGB3A2 polymorphism at positions -112G>A was associated with GD both in Chinese and Caucasian population.

The new perspectives on genetic studies of type 2 diabetes and thyroid diseases

Recently, genome-wide association studies (GWAS) have led to the discovery of hundreds of susceptibility loci that are associated with complex metabolic diseases, such as type 2 diabetes and hyperthyroidism. The majority of the susceptibility loci are common across different races or populations; while some of them show ethnicity-specific distribution. Though the abundant novel susceptibility loci identified by GWAS have provided insight into biology through the discovery of new genes or pathways that were previously not known, most of them are in introns and the associated variants cumulatively explain only a small fraction of total heritability. Here we reviewed the genetic studies on the metabolic disorders, mainly type 2 diabetes and hyperthyroidism, including candidate genes-based findings and more recently the GWAS discovery; we also included the clinical relevance of these novel loci and the gene-environmental interactions. Finally, we discussed the future direction about the genetic study on the exploring of the pathogenesis of the metabolic diseases.

The associations between the polymorphisms in the CTLA-4 gene and the risk of Graves' disease in the Chinese population

Background

The associations between the polymorphisms in Cytotoxic T lymphocyte-associated molecule-4 (CTLA-4) gene and Graves’ disease (GD) have been extensively investigated in Chinese population. However, the results were inconsistent. The objective of this study is to investigate the associations between the polymorphisms in CTLA-4 gene and the risk of GD by meta-analysis.

Methods

We searched Pubmed database, Medline (Ovid) database, CNKI database and Wanfang database, covering all studies until August 11, 2012. Statistical analysis was performed by using the Revman4.2 software and the Stata10.0 software.

Results

A total of 28 case–control studies concerning the most widely studied three polymorphisms [+49A/G(rs231775), -318C/T(rs5742909) and CT60(rs3087243)] for Chinese population in 21 publications were included. The results suggested that the G allele carriers (GG+GA) might have an increased risk of GD when compared with the AA homozygote carriers for the +49A/G polymorphism (GG+GA vs. AA: OR = 2.57, 95%CI = 1.87-3.52). However, as to the -318C/T polymorphism and CT60 polymorphism, the results indicated that the variant allele carriers might have decreased risks of GD when compared with the homozygote carriers (−318C/T: TT+TC vs. CC: OR = 0.78, 95%CI = 0.62-0.97; CT60: AA+AG vs. GG: OR = 0.64, 95%CI = 0.52-0.78).

Conclusions

The current meta-analysis indicated that the polymorphisms in the CLTA-4 gene might be risk factors for GD in the Chinese population. In future, more large-scale case–control studies are needed to validate these results.

Cytokine gene polymorphisms and Alzheimer's disease in Brazil

BACKGROUND

Single-nucleotide polymorphisms in genes encoding immunological mediators can affect the biological activity of these molecules by regulating transcription, translation, or secretion, modulating the genetic risk of inflammatory damage in Alzheimer's disease (AD). Nonetheless, the Brazilian contingent is highly admixed, and few association trials performed herein with AD patients have considered genetic ancestry estimates as co-variables when investigating markers for this complex trait.

METHODS

We analyzed polymorphisms in 10 inflammatory genes and compared the genotype distribution across outpatients with late-onset AD and noncognitively impaired subjects from Midwest Brazil under a strict criterion, and controlling for ancestry heritage and ApoE genotype.

RESULTS

Our findings show an almost 40% lower chance of AD (p = 0.004) among homozygotes of the IL10 -1082A allele (rs1800896). Dichotomization to ApoE and mean ancestry levels did not affect protection, except among those with greater European or minor African heritage.

CONCLUSION

The IL10 locus seems to affect the onset of AD in a context sensitive to the genetic ancestry of Brazilian older adults.

Association of the IL-10 polymorphisms and periodontitis: a meta-analysis

No clear consensus has been reached regarding the association of IL-10 polymorphisms and periodontitis. Therefore, we performed a meta-analysis of case-control studies and a systemic review in an effort to systematically summarize the existing knowledge. Studies were identified by searching PubMed database until December 2011. IL-10 -1082 (-1087) A>G, -819 (-824) C>T and -592 (-597) C>A polymorphisms were included in the present meta-analysis. We calculated the specific odds ratios along with their 95 % confidence intervals to compare the distribution of alleles and genotypes between cases and controls. An additive "per-allele" model (major allele vs. minor allele) was performed, and dominant and recessive models were also considered. The random-effects model was applied for the analysis. Cumulative analysis was also performed. Heterogeneity and publication bias were assessed. Nine case-control studies involving 841 periodontitis cases (644 chronic periodontitis and 197 aggressive periodontitis cases) and 748 controls were included. We found statistically significant association of IL-10 -819 (-824) C>T and IL-10 -592 (-597) C>A polymorphisms in Caucasians. The IL-10 -819 (-824) T and -592 (-597) A alleles may confer a relative increase in the risk for chronic periodontitis in Caucasians. Future studies may be important to reinforce these findings.