Association of CTLA-4 gene polymorphism with Graves' disease and ophthalmopathy in Iranian patients

Genetics, Epigenetics, Cellular Immunology, and Gut Microbiota: Emerging Links With Graves' Disease

Graves’ disease (GD) is a well-known organ-specific autoimmune disease characterized by hyperthyroidism, goiter, and exophthalmos. The incidence of GD is approximately 2.0–3.0% in China and 0.5–2.0% in Western countries. Due to the complex pathogenesis and etiology of GD, current treatment methods have great side effects that seriously endanger human health. Therefore, it is particularly important to understand the pathogenesis of GD. Various studies have shown that genetics, epigenetics, cellular immunology, and gut microbiota are all involved in the development of GD. Genetically, CD25 gene and VDR gene polymorphisms are involved in the development of GD by increasing the ratio of Th17/Treg cells. Epigenetically, miR-23a-3p and lncRNA-MEG3 lead to Th17/Treg imbalance and participate in the progression of GD. Moreover, commensal microbe deletion can disrupt Th17/Treg balance and participate in the occurrence of GD. The imbalance of Th17/Treg cells induced by genetics, epigenetics, and gut microbiota plays a vital role in the pathogenesis of GD. Therefore, this article reviews the role of genetics, epigenetics, cellular immunology, and gut microbiota in the pathogenic mechanism of GD. This may lead to the development of novel therapeutic strategies and providing promising therapeutic targets.

The VDR gene confers a genetic predisposition to Graves' disease and Graves' ophthalmopathy in the Southwest Chinese Han population

OBJECTIVE

Graves' disease (GD) is a common autoimmune disease manifesting with diffuse symmetric thyroid gland enlargement, pretibial myxedema, and Graves' ophthalmopathy (GO). Recently, the vitamin D receptor (VDR) gene has been linked to various autoimmune diseases. This study aimed to investigate the association of VDR gene polymorphisms with susceptibility to GD and GO in the Southwest Chinese Han population.

METHODS

A two-stage association study was performed in 1,209 controls and 650 GD patients by PCR-RFLP assay. Real-time PCR and ELISA were carried out to quantify gene expression and cytokine production.

RESULTS

The first-stage study showed that the frequency of VDR/Apa I AA genotype was significantly increased in GD (Pc = 1.67 × 10^-2, OR = 1.98). The second-stage and combined studies confirmed the association of VDR/Apa I with GD (AA genotype: Pc = 3.45 × 10^-4, OR = 1.87; A allele: Pc = 2.62 × 10^-2, OR = 1.20). The stratification analysis showed that GO patients had a higher frequency of the VDR/Apa I AA genotype (Pc = 8.69 × 10^-5, OR = 2.84). Functional experiments showed a decreased VDR expression and TGF-β1 production as well as an increased IL-17 production in VDR/Apa I AA genotype carriers.

CONCLUSION

The VDR/Apa I polymorphism is significantly associated with GD and GO, and it may be involved in the development of GD and GO by influencing VDR mRNA expression levels and the secretion levels of cytokines.

Investigation of the Correlation between Graves' Ophthalmopathy and CTLA4 Gene Polymorphism

Graves’ disease (GD) is an autoimmune inflammatory disease, and Graves’ ophthalmopathy (GO) occurs in 25–50% of patients with GD. Several susceptible genes were identified to be associated with GO in some genetic analysis studies, including the immune regulatory gene CTLA4. We aimed to find out the correlation of CTLA4 gene polymorphism and GO. A total of 42 participants were enrolled in this study, consisting of 22 patients with GO and 20 healthy controls. Chi-square or Fisher’s exact test were used to appraise the association between Graves’ ophthalmopathy and CTLA4 single nucleotide polymorphisms (SNPs). All regions of CTLA4 including promoter, exon and 3’UTR were investigated. There was no nucleotide substitution in exon 2 and exon 3 of CTLA4 region, and the allele frequencies of CTLA4 polymorphisms had no significant difference between patients with GO and controls. However, the genotype frequency of “TT” genotype in rs733618 significantly differed between patients with GO and healthy controls (OR = 0.421, 95%CI: 0.290–0.611, p = 0.043), and the “CC” and “CT” genotype in rs16840252 were nearly significantly differed in genotype frequency (p = 0.052). Haplotype analysis showed that CTLA4 Crs733618Crs16840252 might increase the risk of GO (OR = 2.375, 95%CI: 1.636–3.448, p = 0.043). In conclusion, CTLA4 Crs733618Crs16840252 was found to be a potential marker for GO, and these haplotypes would be ethnicity-specific. Clinical application of CTLA4 Crs733618Crs16840252 in predicting GO in GD patients may be beneficial.

Association of Cytotoxic T Lymphocyte Antigen-4 Gene Polymorphisms with Psoriasis Vulgaris: A Case-Control Study in Turkish Population

Psoriasis is a common, chronic, and autoimmune skin disease in which dysregulation of immune cells, particularly T cells, is thought to play an important role in the pathogenesis. Cytotoxic T lymphocyte antigen-4 (CTLA-4) expressed only on activated T cells is an immunoregulatory molecule and plays a role in the pathogenesis of autoimmune disorders. We aimed to determine whether CTLA-4 gene polymorphisms are associated with development and/or clinical features of psoriasis vulgaris (Pv). Genotyping of SNPs (−318C>T, +49A>G, and CT60A>G) in CTLA-4 gene was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 103 Pv patients and 102 controls. No statistically significant associations were detected in any of the investigated genetic models for the −318C>T polymorphism. The genotype distributions of +49A>G and CT60A>G were associated with Pv development. In haplotype analysis, while frequency of CAA haplotype was significantly higher in the control group, frequencies of CGG and CAG haplotype were significantly higher among the patients. However, all of CTLA-4 polymorphisms and haplotypes do not have an effect on severity and onset age of Pv. In conclusion, the +49A>G and CT60A>G polymorphisms may be risk factors for Pv development. Furthermore, CGG and CAG haplotypes may contribute to Pv development, while CAA haplotype may be protective against Pv.

Thyroid-Associated Orbitopathy and Biomarkers: Where We Are and What We Can Hope for the Future

Background

Thyroid-associated orbitopathy (TAO) is the most common autoimmune disease of the orbit. It occurs more often in patients presenting with hyperthyroidism, characteristic of Graves' disease, but may be associated with hypothyroidism or euthyroidism. The diagnosis of TAO is based on clinical orbital features, radiological criteria, and the potential association with thyroid disease. To date, there is no specific marker of the orbital disease, making the early diagnosis difficult, especially if the orbital involvement precedes the thyroid dysfunction.

Summary

The goal of this review is to present the disease and combine the available data in the literature concerning investigation of TAO biomarkers.

Conclusions

Despite the progress done in the understanding of TAO disease, some important pieces are still missing. Typically, for the future, major efforts have to be done in the discovery of new biomarkers, validation of the suspected candidates on multicenter cohorts with standardized methodologies, and establishment of their clinical performances on the specific clinical application fields in order to improve not only the management of the TAO patients but also the therapeutic options and follow-up.

Association between rs3087243 and rs231775 polymorphism within the cytotoxic T-lymphocyte antigen 4 gene and Graves' disease: a case/control study combined with meta-analyses

We conducted a case/control study to assess the impact of SNP rs3087243 and rs231775 within the CTLA4 gene, on the susceptibility to Graves' disease (GD) in a Chinese Han dataset (271 cases and 298 controls). The frequency of G allele for rs3087243 and rs231775 was observed to be significantly higher in subjects with GD than in control subjects (p = 0.005 and p = 0.000, respectively). After logistic regression analysis, a significant association was detected between SNP rs3087243 and GD in the additive and recessive models. Similarly, association for the SNP rs231775 could also be detected in the additive model, dominant model and recessive model. A meta-analysis, including 27 published datasets along with the current dataset, was performed to further confirm the association. Consistent with our case/control results, rs3087243 and rs231775 showed a significant association with GD in all genetic models. Of note, ethnic stratification revealed that these two SNPs were associated with susceptibility to GD in populations of both Asian and European descent. In conclusion, our data support that the rs3087243 and rs231775 polymorphisms within the CTLA4 gene confer genetic susceptibility to GD.

[Association between CTLA-4 gene polymorphism and Henoch-Schönlein purpura in children]

OBJECTIVE

To investigate the association between CTLA-4 gene polymorphism and Henoch-Schönlein purpura (HSP) in children.

METHODS

Sixty children who were diagnosed with HSP were enrolled as the case group, consisting of 33 males and 27 females. Thirty healthy children were enrolled as the control group. The patients were further divided into HSP nephritis (HSPN) and non-HSPN groups (n=30 each) according to the presence or absence of nephritis. Polymerase chain reaction-restriction fragment length polymorphism was used to analyze the genotype and allele frequencies at +49 and -1722 loci.

RESULTS

AA, AG, and GG genotypes were detected at +49; neither genotype nor allele frequencies showed significant differences between the case and control groups, between the HSPN and non-HSPN groups, and between male and female patients (P>0.05). TT, TC, and CC genotypes were detected at -1722; neither genotype nor allele frequencies showed significant differences between the case and control groups and between male and female patients (P>0.05). There were significant differences in CC genotype frequency and T and C allele frequencies between the HSPN and non-HSPN groups (P<0.05). Combinational analysis of +49 A/G and -1722 T/C showed no significant differences in the genotype frequency between the case and control groups and between male and female patients (P>0.05). GG-CC combination showed a significant difference between the HSPN and non-HSPN groups (P<0.05).

CONCLUSIONS

CTLA-4 +49 A/G polymorphism is not associated with HSP. CC genotype and C allele of CTLA-4 -1722 and the combination of GG at +49 A/G and CC at -1722 T/C may be risk factors for HSPN.

Pooled genome wide association detects association upstream of FCRL3 with Graves' disease

Background

Graves’ disease is an autoimmune thyroid disease of complex inheritance. Multiple genetic susceptibility loci are thought to be involved in Graves’ disease and it is therefore likely that these can be identified by genome wide association studies. This study aimed to determine if a genome wide association study, using a pooling methodology, could detect genomic loci associated with Graves’ disease.

Results

Nineteen of the top ranking single nucleotide polymorphisms including HLA-DQA1 and C6orf10, were clustered within the Major Histo-compatibility Complex region on chromosome 6p21, with rs1613056 reaching genome wide significance (p = 5 × 10⁻⁸). Technical validation of top ranking non-Major Histo-compatablity complex single nucleotide polymorphisms with individual genotyping in the discovery cohort revealed four single nucleotide polymorphisms with p ≤ 10⁻⁴. Rs17676303 on chromosome 1q23.1, located upstream of FCRL3, showed evidence of association with Graves’ disease across the discovery, replication and combined cohorts. A second single nucleotide polymorphism rs9644119 downstream of DPYSL2 showed some evidence of association supported by finding in the replication cohort that warrants further study.

Conclusions

Pooled genome wide association study identified a genetic variant upstream of FCRL3 as a susceptibility locus for Graves’ disease in addition to those identified in the Major Histo-compatibility Complex. A second locus downstream of DPYSL2 is potentially a novel genetic variant in Graves’ disease that requires further confirmation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3276-z) contains supplementary material, which is available to authorized users.

Genetic variations in the SOCS3 gene in patients with Graves' ophthalmopathy

AIMS

To explore the role of the suppressor of cytokine signalling 3 (SOCS3) gene in Graves' ophthalmopathy (GO) patients.

METHODS

A case-control study was conducted in a Chinese Han population by recruiting 114 Graves' disease (GD) patients with GO and 156 GD patients without GO. We determined SOCS3 mRNA and protein levels in Epstein-Barr virus-transformed lymphoblastoid cell lines (EBV-LCLs) from peripheral blood mononuclear cells (PBMCs) by quantitative real-time (QRT)-PCR analysis and western blot analysis. We also genotyped five single nucleotide polymorphisms (SNPs) in the SOCS3 locus (SOCS3 rs12952093, rs4969170, rs4969168, rs4969169 and rs2280148) in all 270 GD patients using ligase detection reaction and multiplex PCR analyses. QRT-PCR and western blot assays were then performed to compare SOCS3 mRNA and protein levels between the rs4969170 AA and GG genotype groups from 20 GO patients.

RESULTS

Basal SOCS3 mRNA and protein expression levels were significantly increased in patients with GO (p<0.05). The SOCS3 rs4969170 AA genotype was strongly associated with GO (OR=3.5, 95% CI 1.6 to 7.5, p=0.001). The AA genotype carriers had significantly higher SOCS3 mRNA and protein levels than those with the GG genotype (p<0.05).

CONCLUSIONS

Patients with GD who carry the AA genotype of the rs4969170 SNP in SOCS3 are more susceptible to the development of GO.

[Association of CTLA4 and TNF gene polymorphisms with endocrine ophthalmopathy in ethnic Russian patients with Graves' disease]

AIM

To analyze the associations of the rs3087243 CTLA4 polymorphism and the rs1800629 TNF polymorphism with endocrine ophthalmopathy (EOP) in ethnic Russian patients with Graves' disease (GD).

MATERIAL AND METHODS

The case-control study enrolled 205 patients with GD. The distribution of alleles and genotypes of the rs3087243 CTLA4 and rs1800629 TNF polymorphisms was studied in 141 patients with GD and EOP (a GD+EOP group) and 64 patients with GD without EOP (a GD-EOP group). The polymorphic alleles were identified by polymerase chain reaction-restriction fragment length analysis.

RESULTS

The patients with GD in their history and EOP had significantly higher frequencies of A allele and AA genotype and a lower proportion of G allele and GG genotype of the rs3087243 CTLA4 polymorphism. Comparative analysis revealed no significant differences in the frequency of the alleles and genotypes of the rs1800629 TNF polymorphism.

CONCLUSION

The rs3087243 CTLA4 polymorphism is associated with the risk of EOP in ethnic Russian patients with GD.

Associations of CTLA4 Gene Polymorphisms with Graves' Ophthalmopathy: A Meta-Analysis

Many studies have established that T-lymphocyte antigen-4 (CTLA4) is a susceptible gene for Graves' disease (GD). Also many studies showed the association between the CTLA4 exon-1 49A/G polymorphism and the risk of developing Graves' ophthalmopathy (GO) in GD patients. But those results were inconsistent. In recent years many new studies were published which helped to shed light on the relationship of CTLA4 SNP49 with GO. So we performed the meta-analysis to explore the association between the SNP49 and GO susceptibility in GD patients. Studies up to February 29, 2012, were searched by using PubMed. The odds ratio was used to evaluate the strength of the association. Altogether 12 case-control studies involving 2,505 participants were included in the meta-analysis. Results showed that the G allele was related to the increased risk of GO compared with the A allele under allelic genetic model (OR = 1.14, 95% CI: 1.14–1.72, P = 0.001) in European subgroup. No publication bias was detected. Our results showed that the SNP49 polymorphism of CTLA4 gene was related to increased risk of GO.

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.

Graves' ophthalmopathy: a review of immunogenetics

Graves’ disease (GD) is the most common cause of thyrotoxicosis and often involves the orbits. Graves’ ophthalmopathy (GO), also known as Thyroid Eye Disease (TED), can be clinically significant and advance to sight-threatening stages. Our knowledge of the immunogenetic pathophysiology of GO is rapidly expanding. The present review is an attempt to summarize the current state of knowledge on the immunogenetics of GO. First we briefly review the epidemiology and clinical importance of GO, and then we describe in detail the macromolecular pathogenesis and finally immunogenetics of GO. Discrepancies between the results from various reports and the limitations of the available data are discussed. In particular, there is a scarcity of data from non-Asian populations. While several studies have demonstrated significant associations between polymorphisms in certain genes (especially CTLA-4, HLA-DRB-1, and TNF-α), there is a need for studies that investigate the relationship between polymorphisms and both serum and local concentrations of the resulting proteins. A complete understanding of GO susceptibility and pathogenesis has not been yet possible due to a number of important knowledge gaps that need to be filled by future research.

Association between the CTLA-4 +49A/G polymorphism and Graves' disease: A meta-analysis

The +49A/G polymorphism of the cytotoxic T-lymphocyte-associated antigen-4 gene (CTLA-4) has been associated with Graves’ disease (GD). However, results have been inconsistent. The aim of this study was to quantitatively summarize the evidence for CTLA-4 +49A/G polymorphism and GD. Electronic search of PubMed was conducted to select studies. Case-control studies containing available genotype frequencies of CTLA-4 +49 were chosen, and Odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of this association. Forty-two case-control studies including 8,288 cases and 9,372 controls were identified. Three studies were eliminated from the total 42 studies due to a p-value <0.05 (p-value for Hardy-Weinberg equilibrium in control group) in these studies which induced significant publication bias. The overall results suggested that the variant genotypes were highly associated (p<0.01) with GD risk in all genetic models (additive model: OR, 1.443; 95% CI, 1.319–1.578; p<0.001; recessive model: OR, 1.589; 95% CI, 1.396–1.808; p<0.001; dominant model: OR, 1.621; 95% CI, 1.430–1.837; p<0.001). Similarly, in the subgroup analyses for ethnicity (Caucasian, Asian), the results were positive. This meta-analysis suggests that the CTLA-4 +49A/G polymorphism is highly associated (p<0.01) with increased risk of GD, especially in Caucasians and Asians. To validate this association, further studies with larger participants worldwide are needed to examine associations between this polymorphism and GD.

The association between polymorphisms of B7 molecules (CD80 and CD86) and Graves' ophthalmopathy in a Taiwanese population

OBJECTIVE

This study evaluates whether B7 molecules (CD80 and CD86) could be used as genetic markers for the development of Graves' ophthalmopathy (GO).

DESIGN

Cross-sectional study.

PARTICIPANTS

We included 471 patients with Graves' disease (GD; 200 patients with GO and 271 patients without GO) in a Chinese population in Taiwan.

METHODS

An endocrinologist with substantial experience in thyroid diseases identified GO. Blood samples were taken for DNA extraction from GD subjects. The gene polymorphism of CD80 and CD86 was genotyped by polymerase chain reaction in each patient.

MAIN OUTCOME MEASURES

Genotypes of CD80 and CD86 polymorphism.

RESULTS

We found that the frequency of C allele at position rs_9831894 of the CD86 gene is different in patients with GD (with and without GO; chi-square test, P = 0.0017). In addition, the multifactor dimensionality reduction method was used to identify the best gene-gene interaction to predict the risk of GO. We identified an interaction between CD80_rs9289131 and CD86_rs9872483 (sign test, P = 0.0010). Moreover, the G-A haplotype was shown to have a protective effect in the development of ophthalmopathy among patients with GD (odds ratio, 0.63; 95% confidence interval, 0.44-0.90). Moreover, among patients with GO, the patients carrying the G-A haplotype had a lower level of free thyroxine T(4) than those not carrying the G-A haplotype (P = 0.0001).

CONCLUSIONS

These results suggest that the polymorphisms of the CD86 gene may be used as genetic markers for making the diagnosis and prognosis of GO. Therefore, GO could be a disease with complex genetic factors, resulting from the existing gene-gene interaction found in the present study.

Disease association of the CD103 polymorphisms in Taiwan Chinese Graves' ophthalmopathy patients

OBJECTIVE

To evaluate whether variations in the CD103 gene could be associated with Graves' ophthalmopathy (GO) in patients with Graves' disease.

DESIGN

Case-control study.

PARTICIPANTS

A total of 484 Chinese patients with Graves' disease in Taiwan, including 203 patients with GO and 281 patients without GO, were enrolled.

METHODS

Five single nucleotide polymorphisms (SNPs) in CD103 were genotyped using an assay-on-demand allelic discrimination assay and detection system according to the manufacturer's instructions.

MAIN OUTCOME MEASURES

Association of SNPs in CD103 with the development of GO.

RESULTS

The CD103 SNP rs11652878 was associated with GO, which may decrease the risk of GO by 1.57-fold (P = 0.029). The Ht5-GCGCG haplotype, composed of 5 SNPs in the CD103 gene (rs1716, rs3744679, rs11652878, rs16953477, and rs9905739), were protective haplotypes (P = 0.010). Moreover, the heterozygous genotype (Ht5/non-Ht5) was correlated with a reduced risk of GO and high grades of goiter as compared with the non-Ht5/non-Ht5 genotype (P = 0.006 and P = 0.048, respectively). Logistic analysis confirmed the contribution of CD103 rs11652878 to the protection of GO.

CONCLUSIONS

These data suggest that patients with Graves' disease in the presence of the G allele of SNP rs11652878, especially Ht5-GCGCG, in CD103 are less susceptible toward the development of GO.

The interleukin-1 family gene polymorphisms and Graves' disease

Genetic factors, including cytokine gene polymorphisms, are potential contributors to the pathogenesis of the Graves' disease (GD). We attempted in this study to determine the association between GD and the following polymorphisms in the interleukin-1 (IL-1) family genes: IL-1alpha (-889C/T), IL-1ss (-511C/T), IL-1ss (+3962C/T), IL-1R (Pst-1 1970C/T) and IL-1RA (Mspa-I 11100C/T). We studied 107 patients with an established diagnosis of GD and 140 healthy controls. Cytokine typing was performed by the polymerase chain reaction with sequence-specific primers assay. Genotype distributions among patients were in Hardy-Weinberg equilibrium for all polymorphisms. The frequency of the IL-1alpha -889T allele was significantly higher in patients than in controls (51.9% vs. 31.6%, OR=2.33, 95% CI=1.61-3.38; p<0.0001). The IL-1RA Msp-I 11100C allele was significantly more frequent in patients than in controls (50.0% vs. 22.9%, OR=3.38, 95% CI=2.29-4.97, p<0.0001). No significant associations were found for other polymorphisms. Although the IL-1 family has well-known roles in GD pathogenesis, the contributions of their genetic variations to the disease are unclear. In this study, we documented a highly significant association between GD and polymorphism in IL-1alpha and IL-1RA genes. Further studies in other populations are necessary to confirm our results.

Graves' disease and gene polymorphism of TNF-α, IL-2, IL-6, IL-12, and IFN-γ

The role of genetic factors in the pathogenesis of Graves' disease (GD) is not clear. The purpose of this study was to investigate the association between single nucleotide polymorphisms in pro-inflammatory cytokine genes and GD in Iranian patients. A case-control hospital-based study was carried out on 107 GD patients and 140 healthy controls. Cytokine typing was performed by polymerase chain reaction with sequence-specific primers (PCR-SSP) assay. The allele and genotype frequencies of the following cytokine genes were determined: TNF-α (-308A/G, -238A/G), IL-2 (-330T/G, +166G/T), IL-6 (-174C/G, A/G nt565), IL-12 (-1188A/C), and IFN-γ (UTR 5644A/T). The following alleles and genotypes were significantly overrepresented in patients: TNF-α -308A allele (P < 0.01) and AA genotype (P < 0.05), IL-2 -330G allele (P < 0.01) and GG genotype (P < 0.01), IL-6 -174C allele (P < 0.01) and CC genotype (P < 0.01), IL-12 -1188C allele (P < 0.01) and CC genotype (P < 0.01), IFN-γ UTR5644T allele (P < 0.01) and TT genotype (P < 0.01). In conclusion, this is the first study to show a significant association between GD and IL-2 -330G, IL-12 -1188C, and IFN-γ UTR 5644T alleles. Our results support the hypothesis that polymorphism in pro-inflammatory cytokines might be involved in predisposition to GD.

Graves' ophthalmopathy and gene polymorphisms in interleukin-1alpha, interleukin-1beta, interleukin-1 receptor and interleukin-1 receptor antagonist

PURPOSE

Interleukin-1 (IL-1) is known to have an important role in pathogenesis of Graves' ophthalmopathy (GO). Polymorphisms in IL-1 gene have been associated with autoimmune reactions. This study aimed to investigate the association of GO with single-nucleotide polymorphisms (SNPs) in the IL-1 family (IL-1alpha, IL-1beta, IL-1 receptor [IL-1R] and IL-1 receptor antagonist [IL-1RA]).

METHODS

A total of 57 patients of Graves' disease without GO, 50 patients with GO and 140 healthy controls were enrolled. Patients were recruited consecutively from the outpatient endocrine clinic of a large university general hospital. Cytokine typing was performed by the polymerase chain reaction with sequence-specific primers assay. The allele and genotype frequencies of the following polymorphisms were determined: IL-1alpha (-889C/T), IL-1beta (-511C/T), IL-1beta (+3962C/T), IL-1R (Pst-1 1970C/T) and IL-1RA (Mspa-1 11100C/T). Genotype distributions among patients were in Hardy-Weinberg equilibrium for all polymorphisms.

RESULTS

Among the five SNPs studied, the frequencies of the T allele and the TT genotype of IL-1alpha (-889C/T) were significantly higher among patients with GO than those without GO (odds ratio [OR] = 2.16, 95% confidence interval [CI] = 1.25-3.74; P = 0.006 and 5.67, 95% CI = 1.66-49.34; P = 0.005, respectively). For IL-1RA (Mspa-1 11100C/T), the frequencies of the C allele and the CC genotype were significantly higher among patients with GO (OR = 2.31, 95% CI = 1.34-4.00; P = 0.004 and 6.73 95% CI = 1.94-23.36; P = 0.004, respectively; P < 0.01). No significant association was found for other SNPs.

CONCLUSION

This is the first study to show a positive correlation between polymorphisms in the IL-1alpha and IL-1RA genes and susceptibility to GO. These findings promote further research into genetic correlates of GO.