Risk Of Graves' Disease Research Articles

Association of TSHR gene intron 1 and 4p14 single-nucleotide polymorphisms and gene-gene interactions with Graves'disease

Objective To identify the association of thyroid stimulating hormone receptor(TSHR)gene intron 1 susceptible loci and 4p14 susceptible locus rs6832151 polymorphisms with Graves' disease(GD)in Han Chinese population in Bengbu, Anhui, China. The gene-gene interaction among TSHR intron 1 susceptible loci and 4p14 susceptible locus rs6832151 was also investigated. Methods The genotypes of the single-nucleotide polymorphisms(SNPs)were analyzed by Taqman probe technique on Fluidigm EP1 platform in 611 patients with GD and 555 control subjects, and linkage analysis, correlation analysis, haplotype analysis, and epistasis analysis with them were performed. Results Six SNPs in two candidate genes(rs12101261, rs4903964, rs179247, rs2284722 and rs17111394 in TSHR, rs6832151 in 4p14)were associated with GD(all P<0.05). The frequency distributions of haplotypes of SNPs in TSHR intron 1(AGTA, GGCG, AATA, and CC)were significantly different between GD and control groups(all P<0.01). There existed the interactions between rs179247 and rs12101261 in TSHR(P=0.001)and among rs179247(TSHR), rs4903964(TSHR)and rs6832151(4p14)(P=0.001). Conclusions rs683215 in 14p14 and rs12101261, rs4903964, rs179247, rs2284722 and rs17111394 in TSHR intron 1 were susceptible loci of GD in the Chinese Han population from Bengbu. The haplotypes in TSHR intron 1 were associated with GD. There exists the interaction between the SNPs in TSHR and 4p14, which may change the risk of GD. (Chin J Endocrinol Metab, 2016, 32: 292-297) Key words: Graves disease; TSHR gene intron 1; 4p14; Polymorphism, single nucleotide

Association of Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4) Gene Polymorphisms with Autoimmune Thyroid Disease in Children and Adults: Case-Control Study.

Autoimmune thyroid disease (AITD), including Graves disease (GD) and Hashimoto disease (HD), is an organ-specific autoimmune disease with a strong genetic component. Although the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) polymorphism has been reported to be associated with AITD in adults, few studies have focused on children. The aim of our study was to investigate whether the CTLA4 polymorphisms, including -318C/T (rs5742909), +49A/G (rs231775), and CT60 (rs3087243), were associated with GD and HD in Han Chinese adults and children. We studied 289 adult GD, 265 pediatric GD, 229 pediatric HD patients, and 1058 healthy controls and then compared genotype, allele, carrier, and haplotype frequencies between patients and controls. We found that CTLA4 SNPs +49A/G and CT60 were associated with GD in adults and children. Allele G of +49A/G was significantly associated with GD in adults (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.21–1.84; corrected P value [Pc] < 0.001) and children (OR, 1.42; 95% CI, 1.15–1.77; Pc = 0.002). Allele G of CT60 also significantly increased risk of GD in adults (OR, 1.63; 95% CI, 1.27–2.09; Pc < 0.001) and GD in children (OR, 1.58; 95% CI, 1.22–2.04; Pc < 0.001). Significant linkage disequilibrium was found between +49A/G and CT60 in GD and control subjects (D’ = 0.92). Our results showed that CTLA4 was associated with both GD and HD and played an equivalent role in both adult and pediatric GD in Han Chinese population.

Plasma VEGF-related polymorphisms are implied in autoimmune thyroid diseases

Autoimmune thyroid diseases (AITD), including Graves’ disease (GD) and Hashimoto thyroiditis (HT), are complex multifactorial diseases. Vascular endothelial growth factor (VEGF) is implicated in various inflammatory diseases, especially autoimmune diseases. Our aim was to elucidate the relationships between plasma VEGF levels and four genome-wide association study-identified single nucleotide polymorphisms (SNPs) related to VEGF with AITD in Tunisian patients. A total of 364 healthy controls and 389 patients with AITD were genotyped for the SNPs rs6921438, rs4416670, rs6993770 and rs10738760. Levels of thyroid hormones and antibodies were quantified simultaneously with plasma VEGF after a period of six months of treatment. We found that the minor alleles of rs10738760 and rs6921438 are associated with the presence of GD. A allele of rs10738760 polymorphism is associated with increased plasma levels of free tri-iodothyronin (FT3) while no relationship was found with circulating VEGF plasma levels after six months of treatment. We also showed that the T allele of rs4416670 polymorphism was associated with increased risk of hyperthyroidism in patients treated for six months, independently of their initial diagnosis. There was no significant association between the SNPs and the risk for HT compared with controls. This study shows that AITD are influenced by 3 SNPs linked to VEGF circulating levels. Whereas rs10738760 appeared specific to GD and FT3 production after six months of treatment, rs6921438 and rs4416670 were implicated in the risk for GD. This study opens new ways to test pharmacogenomics concepts in the future especially in GD in which recurrence prognosis is still challenging.

Genetic susceptibility to autoimmune thyroid diseases in a Chinese Han population: Role of vitamin D receptor gene polymorphisms

PurposePrevious studies have found that some immune-related genes were associated with autoimmune thyroid diseases (AITDs). A couple of studies have explored the association between vitamin D (1,25-dihydroxyvitamin D3) receptor (VDR) gene polymorphisms and susceptibility to AITDs in different populations and found conflicting results. This case-control study was designed to evaluate the role of polymorphisms of VDR gene in the predisposition of AITDs in a Chinese Han population. MethodsA total of 417 patients with Graves’ disease (GD), 250 patients with Hashimoto's thyroiditis (HT) and 301 healthy subjects were enrolled. The Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometer (MALDI-TOF-MS) Platform was applied to detect four SNPs (rs1544410, rs2228570, rs731236 and rs7975232) in the VDR gene. ResultsIn the rs7975232 allele A frequency showed a significant increase in GD patients (30.34% vs. 25.42% in controls; P=0.041, OR=1.278, 95%CI=1.010–1.617). However, no relationship was found between clinical phenotypes and the four SNPs. ConclusionsThis result suggests that the VDR gene may be one susceptibility gene which contributes to the risk of GD.

Polymorphism of IL37 gene as a protective factor for autoimmune thyroid disease.

Autoimmune thyroid disease (AITD) comprises Graves' disease (GD) and Hashimoto's thyroiditis (HT). IL37 has been recently proved to be a natural suppressor for innate immunity and acquired immunity. Therefore, this study was conducted to identify the association of IL37 genetic polymorphisms with AITD in Chinese Han population. Polymorphisms of rs3811046/rs3811047/rs2723176/rs272186 in the IL37 gene were assessed in a case-control study comprising 701 GD patients, 301 HT patients and 939 controls. Genetic variants were genotyped by multiplex polymerase chain reaction and ligase detection reaction. The frequencies of the minor allele A of rs2723176 and A of rs2723186 were significantly lower in the GD patients than in the controls (P=0.014, OR=0.774; P=0.014, OR=0.777). After gender stratification, the rs3811046 G allele and the rs3811047/rs2723186 A allele were both significantly associated with a decreased risk of GD in female patients (P=0.030, OR=0.777; P=0.023, OR=0.774; P=0.029, OR=0.761). However, none of the four single nucleotide polymorphisms of IL37 gene showed any significant association with HT. Moreover, haplotype analysis revealed the GCG haplotype conferred increased risk for GD as a whole and in female GD patients (OR=1.213; OR=1.320). The ACG haplotype was associated with an increased risk of HT as a whole (OR=1.567) and in male GD patients (OR=1.820). In contrast, the AAA haplotype showed a protective role for GD as a whole (OR=0.760) and in female GD patients (OR=0.765). Our study strongly supports that the IL37 gene variants are associated with the susceptibility to AITD.

Association between TSHR gene polymorphism and the risk of Graves' disease: a meta-analysis.

Thyroid stimulating hormone receptor (TSHR) is thought to be a significant candidate for genetic susceptibility to Graves' disease (GD). However, the association between TSHR gene polymorphism and the risk of GD remains controversial. In this study, we investigated the relationship between the two conditions by meta-analysis. We searched all relevant case-control studies in PubMed, Web of Science, CNKI and Wanfang for literature available until May 2015, and chose studies on two single nucleotide polymorphisms (SNPs): rs179247 and rs12101255, within TSHR intron-1. Bias of heterogeneity test among studies was determined by the fixed or random effect pooled measure, and publication bias was examined by modified Begg's and Egger's test. Eight eligible studies with 15 outcomes were involved in this meta-analysis, including 6,976 GD cases and 7,089 controls from China, Japan, Poland, UK and Brazil. Pooled odds ratios (ORs) for allelic comparisons showed that both TSHR rs179247A/G and rs12101255T/C polymorphism had significant association with GD (OR=1.422, 95%CI=1.353–1.495, P<0.001, Pheterogeneity=0.448; OR=1.502, 95%CI: 1.410–1.600, P<0.001, Pheterogeneity=0.642), and the associations were the same under dominant, recessive and co-dominant models. In subgroup analyses, the conclusions are also consistent with all those in Asian, European and South America subgroups (P<0.001). Our meta-analysis revealed a significant association between TSHR rs179247A/G and rs12101255T/C polymorphism with GD in five different populations from Asia, Europe and South America. Further studies are needed in other ethnic backgrounds to independently confirm our findings.

Lower Serum 25-Hydroxyvitamin D Level is Associated With 3 Types of Autoimmune Thyroid Diseases.

Autoimmune thyroid diseases (AITD) are common autoimmune disorders. A few studies have analyzed the association between serum vitamin D levels and AITD, and available data remain inconclusive. The aim of this study was to evaluate the association between serum vitamin D levels and 3 types of AITD, that is Graves' disease (GD), Hashimoto's thyroiditis (HT), and postpartum thyroiditis (PPT). Two independent case-control studies were designed. The first is a cross-sectional case-control study in which we examined the levels of 25(OH)D in patients with newly diagnosed GD or HT and in controls; the second is a nested case-control study in which we compared 25(OH)D levels in 610 women who developed PPT during the follow-up after delivery and those who did not. Compared with the controls, GD patients and HT patients had significantly lower 25(OH)D levels. PPT cases also had a lower serum 25(OH)D concentration than controls. Serum 25(OH)D levels were associated with neither antithyroid peroxidase antibody nor antithyroglobulin antibody in GD and HT. There was no significant relationship between thyroid-stimulating hormone and 25(OH)D levels. Every 5 nmol/L increase in serum 25(OH)D concentrations was associated with a 1.55-, 1.62-, and 1.51-fold reduction in GD, HT, and PPT risk, respectively. We observed a lower serum vitamin D levels in AITD patients compared with controls. The lower the vitamin D level is, not vitamin D deficiency per se, the higher the risk for developing AITD will be. However, vitamin D does not have strong association with the titers of thyroid antibodies or the levels of thyroid hormones.

Association of the CTLA4 gene CT60/rs3087243 single-nucleotide polymorphisms with Graves' disease.

It has been widely reported that the CT60 single-nucleotide polymorphism (SNP), which is in the 3'-untranslated region of the cytotoxic T lymphocyte associated 4 (CTLA4) gene, is strongly correlated with certain immune-mediated diseases. The present case-control study aimed to investigate the genetic association between the CT60 SNP within the CTLA4 gene and Graves' disease (GD). A total of 288 patients with GD and 290 control subjects were recruited for the study. The CT60 SNP of the CTLA4 gene was detected by direct DNA sequencing. The results indicated that the frequencies of the GG genotype and G allele in the case group were evidently higher than that in the control group (P=4×10-6 and P=2.9×10-5, respectively). Furthermore, the G/G genotype of the CT60 SNP was associated with an increased risk for GD (odds ratio=2.223). In conclusion, these results suggested that the CT60 SNP is associated with susceptibility to GD. The frequency of the disease-susceptible G allele of CT60 was significantly associated with an increased risk of GD development.

Association of Deoxyribonuclease I Gene Polymorphisms with Graves’ Disease in the Chinese Han Population

Background: This study aimed to investigate the association between the single nucleotide polymorphism (SNP) rs1053874 in the deoxyribonuclease I (DNASE1) gene and Graves’ disease (GD) in the Han Chinese population. Methods: Polymerase chain reaction-restriction fragment length polymorphism analysis and direct sequencing were used to identify the distribution of the SNP rs1053874 in the DNASE1 genes from 284 GD patients and 203 healthy controls, and associations between clinical manifestations of GD and the observed genotype and allele frequencies at the DNASE1 gene were analyzed. Results: In the Han Chinese population, there were significant differences between the GD groups and the controls with respect to genotype and allele frequencies associated with theSNPrs1053874. The risk of GD was greater among carriers of the G allele than non-carriers (OR=0.65, 95% CI: 0.49- 0.86). There were significant differences in genotype and allele frequencies between the GD patients with a history of relapse and the GD patients without history of relapse; furthermore, the G allele of the SNP rs1053874 was associated with relapse in GD patients. Conclusion: This study confirmed that the DNASE1 gene may be a GD susceptibility gene in the in the Southern Chinese Han population. The G allele at the rs1053874 SNP would be a direct genetic risk factor for GD in this population. Furthermore, this allele may be associated with disease relapse.

Heat shock protein 70 polymorphisms in Chinese patients with Graves' disease.

Graves' disease (GD) is a common autoimmune disease mainly affecting the thyroid. However, the correlation between the development of GD and HSP70 alleles has not been reported in the Chinese population. Therefore, the aim of this study was to investigate the association between HSP70 polymorphisms and GD in the Chinese population. A total of 153 patients with GD treated at the Yan'an Affiliated Hospital of Kunming Medical University between October 2010 and August 2013 were enrolled in this study; one hundred and twenty healthy volunteers were included in the control group. HSP70 polymorphisms at positions HSP70-1 +190, HSP70-2 +1267, and HSP70-hom +2437 were genotyped by polymerase chain reaction-restriction fragment length polymorphism. The distribution of the HSP70-2 +1267 GG genotype allele frequencies among GD and control subjects differed significantly (χ(2) = 20.40, P < 0.001; χ(2) = 18.18, P < 0.001). The G allele of HSP70-2 +1267 (Odds ratio = 0.455, 95% confidence interval: 0.315-0.655) conferred a higher risk of developing GD than the A allele. We observed no significant differences in the allelic frequencies of HSP70-1 +190 and HSP70-hom +2437. Therefore, the HSP70-2 +1267 GG genotype and the G allele may increase the risk of GD in Chinese subjects. The results of this study may be useful in identifying patients with increased risk of GD, and offer useful reference data for targeted gene therapy of GD in the future.

Association of Toll-like receptor 7 and 8 gene polymorphisms with Graves' disease in Chinese Cantonese population.

Graves' disease (GD) is a common polygenic multifactorial autoimmune disease. Toll-like receptors (TLRs) play critical roles in the activation of innate and adaptive immune responses. This study investigated the association of TLR7 and TLR8 gene polymorphisms with susceptibility of GD. Five single nucleotide polymorphisms (SNPs), namely, rs179019, rs179010 and rs3853839 in TLR7 and rs3764880 and rs5744088 in TLR8, were evaluated in 332 GD patients and 351 controls using High-Resolution Melting analysis. After adjusting for age, SNP rs179010 was found to decrease the risk of GD in females (OR(T vs C) = 0.64, P = 0.004). In the additive model, the risk of GD decreased significantly as the number of T alleles increased in females [odds ratio (OR) = 0.67 (0.50-0.90), P = 0.007]. The multivariate logistic regression analysis confirmed the independent contribution of rs179010 to the protective effect against GD. This study indicates that rs179010 in TLR7 may be associated with the decreased susceptibility to GD in Chinese Cantonese.

Polymorphisms in TLR1, TLR6 and TLR10 genes and the risk of Graves’ disease

Graves’ disease (GD) is postulated to be caused by the combined effects of susceptibility genes and environmental triggers. Toll-like receptors (TLRs) play a role in the activation of innate and adaptive immune responses in mammalians. The aim of this study was to evaluate the potential association of polymorphisms in TLR1, TLR6 and TLR10 genes with GD in Chinese Cantonese population. Seven single nucleotide polymorphisms (i.e. rs4833095 and rs5743565 in TLR1; rs5743808 in TLR6; and rs4504265, rs11466655, rs11096957 and rs10856839 in TLR10) were evaluated in 332 GD patients and 351 unrelated controls from Chinese Cantonese population. SNP rs5743565 in TLR1 conferred a protective effect against GD. The minor allele G of rs5743565 decreased the risk of GD in all cases (odds ratio; ORG vs. A = 0.72 (0.58–0.91); p = 0.005; ptrend = 0.004) and early onset patients (ORG vs. A = 0.72 (0.56–0.91); p = 0.007; ptrend = 0.006). This study provided evidence that genetic variation rs5743565 in TLR1 might be associated with the decreased susceptibility of GD.

Association of TLR4 and TLR5 gene polymorphisms with Graves’ disease in Chinese Cantonese population

Graves’ disease (GD) is postulated to be caused by the combined effects of susceptibility genes and environmental triggers. Toll like receptors (TLRs) play a role in the activation of innate and adaptive immune responses in mammalians. The aim of this study was to evaluate the potential association of TLR4 and TLR5 gene polymorphisms with GD in Chinese Cantonese population. Four single nucleotide polymorphisms (SNPs), rs11536889 and rs7873784 in TLR4, rs2072493 and rs5744174 in TLR5, were evaluated in 332 GD patients and 351 unrelated controls from Chinese Cantonese population. The minor allele C of TLR5 rs5744174 decreased the risk to GD in females (ORC vs. T=0.63; p=0.003; ptrend=0.003). Under a dominant model, rs5744174 conferred a protective effect in all cases (ORCC/CT vs. TT=0.65; p=0.009) or female subset (ORCC/CT vs. TT=0.57; p=0.002). Under a co-dominant model, rs5744174 also conferred a protective effect in all cases (ORTC vs. TT=0.64; p=0.008) and females (ORTC vs. TT=0.57; p=0.002). The haplotype A-C of TLR5 (rs2072493–rs5744174) decreased the risk of GD in females (OR=0.62; p=0.002). The other three SNPs were not found associated with GD. This study provided evidence that polymorphisms in TLR5 might be associated with decreased susceptibility of GD in females.

Polymorphisms of the TNFAIP3 region and Graves' disease

Autoimmune thyroid disease (AITD) is a multifactorial organ-specific autoimmune disorder, and both genetic susceptibility and environmental factors are involved in its etiology. TNFAIP3 encodes the ubiquitin-modifying enzyme (A20), a key regulator of inflammatory signaling pathways. The aim of the present study was to evaluate the association between TNFAIP3 gene polymorphisms and AITD in Chinese Han population. Three single nucleotide polymorphisms (SNPs) in TNFAIP3 gene locus (rs598493, rs610604 and rs661561) were detected in a set of 667 patients with AITD and 301 controls in Han Chinese population using the Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometer (MALDI-TOF-MS) Platform. Compared with those of the controls, the frequencies of GG genotype of rs598493, the AA genotype of rs610604, the allele G and GG genotype of rs661561 were significantly increased in Graves' disease (GD) patients. However, the frequencies of AG genotype of rs598493 and AC genotype of rs610604 were significantly decreased in GD patients. The ATC haplotype (rs598493, rs661561 and rs610604) was associated with a decreased risk of GD. No significant differences in the three SNPs were observed between HT patients and controls. Our study shows a clear association between the polymorphisms of TNFAIP3 gene and GD, not HT, suggesting that TNFAIP3 gene is likely to be a genetic susceptibility factor to GD.

Lack of Association between the IL-13 C-1112T, G2044A Polymorphisms and Graves’ Disease Risk: Evidence from a Meta-analysis

Background: Previous studies have provided conflicting evidence implicating the IL-13 C-1112T and G2044A polymorphisms in Graves’ disease (GD) risk. We undertook a meta-analysis to address this issue.Methods: The Medline, Pubmed and Web of Science databases were searched for published case-control studies investigating the relation of the IL-13 C-1112T and G2044A polymorphisms with GD risk. Data were extracted using standardized forms and odds ratios (OR) with 95% confidence intervals (CI) were calculated.Results: Available data did not suggest an association between any of the two IL-13 polymorphisms and GD risk. For the C-1112T polymorphism, the combined OR was 0.96 (95% CI: 0.77–1.19) for dominant model (TT + CT vs CC), 0.97 (95% CI: 0.69–1.38) for recessive model (TT vs CT + CC), and 0.97 (95% CI: 0.68–1.39) for homozygote model (TT vs CC). ORs for the G2044A polymorphism were similar. In subgroup analyses stratified by ethnicity, we also did not find associations between these two variants and GD risk in Asians or Caucasians. Sensitivity analyses by excluding each of the involved study in turn did not change the pooled results.Conclusion: The IL-13 C-1112T and G2044A polymorphisms are not associated with GD risk.

Increased TRAb and/or Low Anti-TPO Titers at Diagnosis of Graves’ Disease are Associated with an Increased Risk of Developing Ophthalmopathy after Onset

Patients with low thyroid peroxidase antibodies (anti-TPO) and increased TSH-receptor antibodies (TRAb) at diagnosis of Graves' disease (GD) have been suggested to have an increased risk to develop Graves' ophthalmopathy (GO). The aim was to evaluate if GO development can be predicted.This is an observational study with registration of possible GD and GO risk factors.399 patients with GD were registered 2003-2008 in Malmö, Sweden and out of these 310 were retrospectively followed up to 6 years. The main outcome measures were anti-TPO titer, TRAb titer, smoking habits, radioiodine treatment and GO development.TRAb was assessed with a third generation assay at GD diagnosis in 231 patients. The proportion of patients with GO increased above the median 6.3 IU/L both at diagnosis of GD (p=0.001) and at follow-up (p=0.0001).The distribution of GO patients anti-TPO above or below 20 kIU/L at diagnosis of GD was similar between groups (p=0.239). However at follow-up anti-TPO<20 kIU/L was associated with an increased proportion of newly developed GO as compared to the cohort with anti-TPO>20 kIU/L (p=0.018).87% of patients who developed GO after GD diagnosis had TRAb above 6.3 IU/L and/or anti-TPO below 20 kIU/L. The proportion of GO was doubled in GD patients treated with radioiodine but could not explain the described findingsAnti-TPO<20 kIU/L and/or TRAb>6.3 IE/L at the time of GD diagnosis were associated with an increased risk to develop GO after diagnosis of GD.

Association between the IL1B (-511), IL1B (+3954), IL1RN (VNTR) Polymorphisms and Graves' Disease Risk: A Meta-Analysis of 11 Case-Control Studies

BackgroundData on the association between the interleukin-1 (IL-1) gene polymorphisms and Graves' disease (GD) risk were conflicting. A meta-analysis was undertaken to assess this association.MethodsWe searched for case-control studies investigating the association between the IL1B (-511), IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk. We extracted data using standardized forms and calculated odds ratios (OR) with 95% confidence intervals (CI).ResultsA total of 11 case-control studies were included in this meta-analysis. Available data indicated that the IL1B (-511) polymorphism was associated with GD risk in the overall populations (Caucasians and Asians) in homozygote model (TT vs. CC, OR = 0.86, 95% CI: 0.76–0.97, Pz = 0.015), but not in dominant and recessive models (TT+TC vs. CC: OR = 0.95, 95% CI: 0.81–1.12, Pz = 0.553 and TT vs. TC+CC: OR = 0.82, 95% CI: 0.60–1.12, Pz = 0.205, respectively). No association between the IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk was found in the overall populations in any of the genetic models. In subgroup analyses according to ethnicity, the IL1B (-511) polymorphism was associated with GD risk in Asians in recessive and homozygote models (TT vs. TC+CC: OR = 0.68, 95% CI: 0.55–0.84, Pz<0.001 and TT vs. CC: OR = 0.81, 95% CI: 0.70–0.93, Pz = 0.003, respectively), but not in dominant model (TT+TC vs. CC: OR = 0.92, 95% CI: 0.77–1.11, Pz = 0.389). No association between the IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk was indicated in Asians, and we found no association between the IL1B (-511), IL1B (+3954), IL1RN (VNTR) polymorphisms and GD risk in Caucasians in any of the genetic models.ConclusionThe IL1B (-511) polymorphism, but not the IL1B (+3954) and IL1RN (VNTR) polymorphisms was associated with GD risk in Asians. There was no association between these polymorphisms and GD risk in Caucasians.

Distribution of IgG subclasses of TgAb and TPOAb in sera from patients with Graves' disease, Graves' disease plus Hashimoto's thyroiditis and Hashimoto's thyrotoxicosis

To evaluate the distribution of IgG subclasses of TgAb and TPOAb in sera from patients with Graves' disease (GD), Graves' disease plus Hashimoto's thyroiditis (GH) and Hashimoto's thyrotoxicosis. Patients with GD (n = 33), GH (n = 31) or Hashimoto's thyrotoxicosis (n = 18) diagnosed by fine needle aspiration cytology at Department of Endocrinology of Peking University First Hospital, Beijing Haidian Hospital, China-Japan Friendship Hospital and Civil Aviation General Hospital during the period from January 2010 to May 2013 were enrolled. All of them had TgAb and TPOAb. The total serum IgG and IgG subclasses of TgAb and TPOAb were detected by antigen-specific enzyme-linked immunosorbent assay (ELISA). The prevalence and relative amount of IgG subclasses were calculated and compared among three groups. The levels of TRAb in GD group (21.80(7.53, 40) U/L) were significantly higher than those in GH (7.30(3.10, 25.40) U/L) (P = 0.000) and Hashimoto's thyrotoxicosis groups (4.90(1.69, 16.43) U/L) (P = 0.003). And no significant differences were found in the levels of TgAb and TPOAb. The prevalence of TgAb IgG3 subclass in Hashimoto's thyrotoxicosis group (66.7%) was higher than GD group (35.5%) and GH group (36.4%) and the difference was close to significance (P = 0.066). There were significant differences of relative amount of TgAb IgG2 and TgAb IgG4 among three groups (P = 0.039 and 0.013), and GD patients had higher relative amounts of TgAb IgG2 (0.59(0.34, 0.94)) and TgAb IgG4 (0.57(0.28, 0.97)) than GH patients (TgAb IgG2, 0.31(0.23, 0.34); TgAb IgG4, 0.26(0.09, 0.48)) or patients with Hashimoto's thyrotoxicosis (TgAb IgG2, 0.32(0.24, 0.83); TgAb IgG4, 0.33(0.10, 0.65)) (for TgAb IgG2, P = 0.009 and 0.167; for TgAb IgG4, P = 0.005 and 0.041 respectively). No significant difference was found in the prevalence of each TPOAb IgG subclass. The difference of relative amount of TPOAb IgG2 among three groups was close to significance (P = 0.069). And the relative amount was higher in sera from GD patients (0.39 ± 0.04) than that in GH patients (0.29 ± 0.13) or patients with Hashimoto's thyrotoxicosis (0.26 ± 0.02) (P = 0.104 and 0.002 respectively). The patients with high levels of TgAb IgG2, TgAb IgG4 and TPOAb IgG2 subclasses have a greater risk of GD. The IgG subclass distribution of TgAb and TPOAb might help to differentiate the causes of thyrotoxicosis in autoimmune thyroid diseases.

CTLA-4 polymorphisms (+49 A/G and -318 C/T) are important genetic determinants of AITD susceptibility and predisposition to high levels of thyroid autoantibodies in Polish children - preliminary study.

Autoimmune thyroid diseases (AITDs), including Hashimoto' s thyroiditis (HT) and Graves' disease (GD), are related to environmental and genetic factors. We analyzed the association of cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) gene two polymorphisms (+49 A/G, -318 C/T) with HT and GD development in Polish children, and correlated both polymorphisms with the production of thyroid autoantibodies (TPOAb and TgAb). The study involved 49 AITD patients (age 10-19) with HT (n=25) or GD (n=24) and 69 healthy controls. SNP genotyping was performed using genomic DNA and TaqMan® probes. The obtained results indicated that CTLA-4 +49 GG genotype was significantly more frequent in both HT and GD patients, whereas the AA genotype was more common in controls. CTLA-4-318 CT genotype was significantly more frequent in AITD, and the CC genotype more often occurred in controls. Significantly higher median TPOAb and TgAb values were associated with G allele in HT, and with T allele in GD patients. Concluding, both studied polymorphisms seem to be important genetic determinants of the risk of HT and GD, and appear to be associated with a predisposition to high levels of TAbs and clinical AITD. The obtained results give more information on the distribution of the CTLA-4 polymorphism in Polish AITD children, and further support the proposal that the CTLA-4 gene plays an important role in a TAb production.

Identification of BACH2 as a susceptibility gene for Graves’ disease in the Chinese Han population based on a three-stage genome-wide association study

The BACH2 gene regulates B cell differentiation and function and has been reported to be a shared susceptibility gene for several autoimmune diseases. Our previous genome-wide association study (GWAS) indicated that several single nucleotide polymorphisms (SNPs) in the BACH2 gene are associated with Graves' disease (GD) in the Chinese Han population; however, the association did not achieve genome-wide significance levels. Recently, this association of BACH2 with GD was confirmed in Caucasians in the UK population, but fine mapping in this region has not yet been reported. Here, we provide a refined analysis of a 331-kb region in the BACH2 gene, which harbors 359 SNPs, using GWAS data from 1,442 GD patients and 1,468 controls. The SNPs rs2474619 and rs9344996 were implied as the independent variants associated with GD by forward and two-locus logistic regression analysis. We genotyped eight out of 10 tagSNPs with P<1×10(-3) in 3,508 GD patients and 3,209 controls, the results also showed that rs2474619 was independently associated with GD in the combined population from GWAS and the second stage (P=1.81×10(-5)). The rs2474619 and rs9344996 were further genotyped in the third stage cohorts, and rs2474619 showed evidence of association with GD at genome-wide significance levels in the combined population (P=3.28×10(-8), odds ratio=1.13). The association of rs9344996 with GD can be explained by its linkage to rs2474619 in the combined population. Our study clearly demonstrated that BACH2 is a susceptibility gene for GD in the Chinese Han population and further supported rs2474619, in intron 2 of BACH2, is the best association signal with GD. However, the mechanism by which BACH2 confers increased risk of GD requires further study.