Susceptible alleles of the CD40 and CTLA-4 genes are not associated with the relapse after antithyroid withdrawal in Graves' disease

The genetics of Graves' disease

Graves' disease (GD) is the commonest cause of hyperthyroidism and has a strong female preponderance. Everyday clinical practice suggests strong aggregation within families and twin studies demonstrate that genetic factors account for 60-80% of risk of developing GD. In this review, we collate numerous genetic studies and outline the discoveries over the years, starting with historic candidate gene studies and then exploring more recent genome-wide linkage and association studies, which have involved substantial cohorts of East Asian patients as well as those of European descent. Variants in genes including HLA, CTLA4, and PTPN22 have been shown to have substantial individual effects on disease susceptibility. In addition, we examine emerging evidence concerning the possibility that genetic variants may correlate with relevant clinical phenotypes including age of onset of GD, severity of thyrotoxicosis, goitre size and relapse of hyperthyroidism following antithyroid drug therapy, as well as thyroid eye disease. This review supports the inheritance of GD as a complex genetic trait, with a growing number of more than 80 susceptibility loci identified so far. Future implementation of more targeted clinical therapies requires larger studies investigating the influence of these genetic variants on the various phenotypes and different outcomes of conventional treatments.

Genotype-phenotype correlations in Graves' disease

Graves' disease (GD) is a heterogeneous autoimmune disease affecting with varying degrees of severity the thyroid gland, orbital tissues and skin. The pathogenesis of GD involves a complex interplay between multiple genetic, environmental and endogenous factors. Although the genetic predisposition to GD is well established, the significance of genotype-phenotype correlations and the role of epigenetic modifications in the disease pathogenesis remains largely unknown. In this review, we provide an up-to-date overview of genotype-phenotype correlations and summarize possible clinical implications of genetic and epigenetic markers in GD patients. We will specifically discuss the association of genetic markers and epigenetic modifications with age of GD onset, severity of Graves' hyperthyroidism and the development of clinically evident Graves' orbitopathy.

Prediction of Relapse After Antithyroid Drugs Withdrawal: A Narrative Review

Context: Antithyroid drugs (ATD) are the first-line treatment for Graves’ disease (GD); however, relapse following treatment is approximately 30% - 40% in the first year, and 50% - 60% in the long term. Identification of risk factors that predict relapse, after discontinuing ATD, plays an important role in guiding therapeutic options. Evidence Acquisition: PubMed was used to search for studies published in English between 1995 and 2019. The following search terms were used: Graves’ disease, antithyroid drugs, relapse, recurrence, and outcome. The reference lists from review articles were also included in the search in order to find older journals. Results: Factors associated with a high recurrence rate, as reported in most studies, were divided into phenotype and genotype predictors. Phenotype factors included large goiter size, persistence of high TSH receptor antibody (TRAb), severe hyperthyroidism, smoking, younger age, male sex, and prior history of recurrence. Genotype factors included human leukocyte antigen (HLA), CD40, CTLA-4, PTPN22, Tg, and TSHR genes. In a subgroup analysis by age, genetic factors were better predictors in the younger group, while clinical signs were more useful in the older group. The reliability of using individual baseline risk factors to predict subsequent relapse is poor; however, predictive scores calculated by grouping single risk factors might help to predict future outcomes. Conclusions: Longer normalization time of TRAb, the persistence of a palpable goiter, and harboring genetic risk factors in younger patients are associated with high recurrence rate of GD. Multi-marker prediction models have been proposed and validated to improve the predictive value of relapse after ATD withdrawal.

Benign Thyroid Diseases: Are There Gender-Specific Differences for Diagnosis and Treatment of Nontoxic Thyroid Nodules? Results from a 4-Year Retrospective Analysis of an Endocrine Tumor Board

Introduction

Benign nodular goiters are endemic in Germany and diagnostic thyroidectomy is one of the most frequent surgical procedures. Less than 10% result in a malignant finding which is a poor ratio in comparison to other European countries. There is a female preponderance in almost all thyroid pathologies according to the current literature but not much is known concerning gender-specific differences in thyroid nodules.

Objective

We aimed at finding gender-specific differences in diagnosis and treatment of nontoxic thyroid nodules and focused on preoperative workup as well as cytological and histological findings of patients with solitary and multinodular nontoxic goiters.

Methods

We retrospectively analyzed 392 cases out of 693 thyroid cases managed interdisciplinarily by the endocrine board of a university center between January 2015 and December 2018 (4 years).

Results

The combination of fine needle biopsy and interdisciplinary case discussion resulted in a rate of malignancy of 28.9% in patients undergoing surgery for solitary and multinodular nontoxic goiter. Although there was no significant gender-specific difference in the distributions and malignancy rates of Bethesda categories, male patients had a significantly higher malignancy rate of 40% in our collective (p = 0.04).

Conclusions

Surgical treatment for male patients with suspicious hypofunctioning thyroid nodules should be favored. However, well-designed prospective studies are required to investigate gender-specific recommendations for the treatment of benign thyroid diseases in the future.

Genetic predictors of the development and recurrence of Graves' disease

Graves' disease affects approximately 3 % of women and 0.5 % of men. The first-choice therapy is based on the administration of thyrostatic drugs. However, approximately half of patients relapse within two years of discontinuation. These patients must then decide whether to re-initiate thyrostatics, which may have serious side effects, or to undergo surgery or radioiodine treatment. Familial forms of Graves' disease indicate a significant genetic component, with twin studies demonstrating a contribution of genetic factors up to 70-80 %. The autoimmune nature of the disease involves the human leukocyte antigen (HLA) complex, which has a decisive impact on each individual's immune response. Within HLA, some variants of the DRB1, DQA1 and DQB1 genes appear to be possible predictors of the development and recurrence of Graves' disease. Outside the HLA region, many variants of immunocompetent genes have also been identified as potential Graves' disease predictors. Apart from the immune system, some thyroid-specific genes have been described in relation to the disease. Here, we present current knowledge regarding the genetic components involved in the development and recurrence of Graves' disease. Further, we present original pilot results from a cohort of Czech Graves' disease patients regarding the HLA variants.

Correlations of CTLA-4 exon-1 49 A/G and promoter region 318C/T polymorphisms with the therapeutic efficacy of 131 I radionuclide in graves' disease in Chinese Han population

Graves' disease is an autoimmune process in which the thyroid gland is triggered by autoantibodies, resulting in hyperthyroidism. The purpose of the present study is to elucidate whether exon-1 49 A/G and promoter region 318C/T polymorphisms in the CTLA-4 gene. This study consisted of 653 eligible patients with Graves' disease. After receiving 131I radionuclide therapy, these patients were classified into the remission and non-remission groups. A logistic regression-based model was used to analyze independent factors affecting the patient response to 131I radionuclide therapy. The results showed that CTLA-4 49 A/G was closely related to the efficacy of ¹³¹ I treatment for Graves' disease (AG + GG vs. AA: OR = 6.543, 95%CI = 2.611 ∼ 16.40, P < 0.001; G vs. A: OR = 3.482, 95%CI = 2.457 ∼ 4.934, P < 0.001). Moreover, the findings revealed that haplotype A-C (P < 0.001, OR = 3.592, 95%CI: 2.451 ∼ 5.262) and G-C (P < 0.001, OR = 0.282, 95%CI: 0.204 ∼ 0.391) were associated with the efficacy of ¹³¹ I therapy in treating Graves' disease. Logistic regression analysis indicated that thyroid weight (OR = 0.963, 95%CI = 0.944 ∼ 0.982, P < 0.001) and CTLA-4 exon-1 49 A/G polymorphism (OR = 0.334, 95%CI = 0.233 ∼ 0.478, P < 0.001) independently affect the efficacy of ¹³¹ I therapy in Graves' disease. These data indicated that CTLA-4 exon-1 49 A/G polymorphism may be associated with patient response to radionuclide ¹³¹ I therapy in Graves' disease.

Antithyroid Drug Therapy for Graves' Disease and Implications for Recurrence

Graves' disease (GD) is the most common cause of hyperthyroidism worldwide. Current therapeutic options for GD include antithyroid drugs (ATD), radioactive iodine, and thyroidectomy. ATD treatment is generally well accepted by patients and clinicians due to some advantages including normalizing thyroid function in a short time, hardly causing hypothyroidism, and ameliorating immune disorder while avoiding radiation exposure and invasive procedures. However, the relatively high recurrence rate is a major concern for ATD treatment, which is associated with multiple influencing factors like clinical characteristics, treatment strategies, and genetic and environmental factors. Of these influencing factors, some are modifiable but some are nonmodifiable. The recurrence risk can be reduced by adjusting the modifiable factors as much as possible. The titration regimen for 12-18 months is the optimal strategy of ATD. Levothyroxine administration after successful ATD treatment was not recommended. The addition of immunosuppressive drugs might be helpful to decrease the recurrence rate of GD patients after ATD withdrawal, whereas further studies are needed to address the safety and efficacy. This paper reviewed the current knowledge of ATD treatment and mainly focused on influencing factors for recurrence in GD patients with ATD treatment.

Can we predict relapse in Graves' disease? Results from a systematic review and meta-analysis

BACKGROUND

Identification of pretreatment risk factors predicting relapse in patients with hyperthyroidism of Graves' disease after stopping anti-thyroid drugs (ATD) is decisive to guide therapeutic options.

PURPOSE

We performed a systematic search and meta-analysis to study predictors for relapse after stopping ATD in patients with Graves' disease.

METHODS

Based on a pre-specified protocol, we searched PubMed, EMBASE and Cochrane in July 2015 for case-control, controlled and randomized-controlled trials reporting risk factors for relapse after stopping ATD. The primary endpoint was relapse of disease until follow-up. PRISMA and SIGN statements were used for reviewing the data and assessing the quality of included trials.

RESULTS

We included 54 trials with a total of 7595 participants. Most trials were small with moderate-to-high risk for bias. Ten trials were assessed only qualitatively (2227 patients), genomic data were reported in 13 trials (2178 patients) and 31 trials (4346 patients) were assessed quantitatively. In total, there were 3696 relapses in 7595 patients (48.7%). By using random-effects meta-analysis, orbitopathy, smoking, thyroid volume measured by sonography, goiter size, fT4, tT3, TRAb and TBII were significantly associated with relapse, whereas male vs female sex, age and initial tT4 level did not show significant associations.

CONCLUSIONS

This analysis found several risk factors to predict relapse in Graves' disease, which can be combined in a risk score. Prospective studies should evaluate the prognostic accuracy of such a score to guide treatment decisions.

CD28/CTLA-4/ICOS haplotypes confers susceptibility to Graves' disease and modulates clinical phenotype of disease

Graves' disease, an autoimmune disease with heterogeneous symptoms including Graves' orbitopathy, has a combined genetic/environmental background, where variations within CD28/CTLA-4/ICOS genes are considered as disease markers.Association of CD28c.17+3T>C(rs3116496), CTLA-4g.319C>T(rs5742909), CTLA-4c.49A>G(rs231775), CTLA-4g.*642AT(8_33), CT60(rs3087243), Jo31(rs11571302), ICOSc.1554+4GT(8_15) polymorphisms with susceptibility to Graves' disease and clinical outcome was investigated. The study group comprised of 561 Polish Caucasians, including 172 unrelated Graves' disease patients. CTLA-4c.49A>G, CTLA-4g.319C>T, and CT60 were genotyped by PCR-RFLP; Jo31 and CD28c.17+3C>T by minisequencing; CTLA-4g.*642AT(8_33) and ICOSc.1554+4GT(8_15)-PCR and fluorescence-based technique. CD28c.17+3T>C(rs3116496)T/CTLA-4g.319C>T(rs5742909)C/CTLA-4c.49A>G(rs231775)G/CTLA-4g.*642AT(8_33)(AT_16-21)/CT60(rs3087243)G/Jo31(rs11571302)G/ICOSc.1554+4GT(8_15)(m) and TCA(AT_<16)GT(m) haplotypes increased risk of Graves' disease, especially in males, as well as overall Graves' orbitopathy development with severe outcome. TCG(AT_16-21)GG(l) haplotype increased risk of Graves' disease and reduced the chance of successful medical treatment. Although this haplotype was mainly observed in patients without signs of Graves' orbitopathy, if Graves' orbitopathy developed it favored a Graves' orbitopathy outcome. Haplotype TCA(AT_>21)GT(m) increased Graves' disease risk in women and, in all patients, was linked to Graves' disease without Graves' orbitopathy. TCG(AT_<16)GG(m) haplotype was predominantly observed in patients without Graves' orbitopathy, whereas TCA(AT_16-21)GG(m) was absent in those patients. TCA(AT_16-21)GG(m) occurred in patients with a mild Graves' orbitopathy outcome. The marker CTLA-4g.*642AT(8_33) was the only independent Graves' disease risk factor, whereas CT60 was an independent factor for disease progression. Sporadic Graves' disease was related to presence of CTLA-4c.49A>G[A] and the rare CTLA-4g.319C>T[T] allele variant. Familial background of the disease was exclusively associated with CTLA-4g.*642AT(8_33)[AT_>21]/[AT_>21] genotype. CD28/CTLA-4/ICOS loci may confer inherited susceptibility to Graves' disease or may be involved in susceptibility to Graves' disease and play a pathogenetic role.

Genotype and phenotype predictors of relapse of graves' disease after antithyroid drug withdrawal

BACKGROUND

For patients with Graves' disease (GD), the primary goal of antithyroid drug therapy is to temporarily restore the patient to the euthyroid state and wait for a subsequent remission of the disease. This study sought to identify the predictive markers for the relapse of disease.

METHODS

To do this, we studied 262 GD patients with long enough follow-up after drug withdrawal to determine treatment outcome. The patients were divided into three groups by time of relapse: early relapse group (n = 91) had an early relapse within 9 months, late relapse group (n = 65) had a relapse between 10 and 36 months, and long-term remission group (n = 106) were either still in remission after at least 3 years or relapsed after 3 years of drug withdrawal. We assessed the treatment outcome of 23 SNPs of costimulatory genes, phenotype and smoking habits. We used permutation to obtain p values for each SNP as an adjustment for multiple testing. Cox proportional hazards models was performed to assess the strength of association between the treatment outcome and clinical and laboratory variables.

RESULTS

FOUR SNPS WERE SIGNIFICANTLY ASSOCIATED WITH DISEASE RELAPSE: rs231775 (OR 1.96, 95% CI 1.18-3.26) at CTLA-4 and rs745307 (OR 7.97, 95% CI 1.01-62.7), rs11569309 (OR 8.09, 95% CI 1.03-63.7), and rs3765457 (OR 2.60, 95% CI 1.08-6.28) at CD40. Combining risk alleles at CTLA-4 and CD40 improved the predictability of relapse. Using 3 years as the cutoff point for multivariate analysis, we found several independent predictors of disease relapse: number of risk alleles (HR 1.30, 95% CI 1.09-1.56), a large goiter size at the end of the treatment (HR 1.30, 95% CI 1.05-1.61), persistent TSH-binding inhibitory Ig (HR 1.64, 95% CI 1.15-2.35), and smoking habit (HR 1.60, 95% CI 1.05-2.42).

CONCLUSION

Genetic polymorphism of costimulatory genes, smoking status, persistent goiter, and TSH-binding inhibitory Ig predict disease relapse.

The genetic basis of graves' disease

The presented comprehensive review of current knowledge about genetic factors predisposing to Graves’ disease (GD) put emphasis on functional significance of observed associations. In particular, we discuss recent efforts aimed at refining diseases associations found within the HLA complex and implicating HLA class I as well as HLA-DPB1 loci. We summarize data regarding non-HLA genes such as PTPN22, CTLA4, CD40, TSHR and TG which have been extensively studied in respect to their role in GD. We review recent findings implicating variants of FCRL3 (gene for FC receptor-like-3 protein), SCGB3A2 (gene for secretory uteroglobin-related protein 1- UGRP1) as well as other unverified possible candidate genes for GD selected through their documented association with type 1 diabetes mellitus: Tenr–IL2–IL21, CAPSL (encoding calcyphosine-like protein), IFIH1(gene for interferon-induced helicase C domain 1), AFF3, CD226 and PTPN2. We also review reports on association of skewed X chromosome inactivation and fetal microchimerism with GD. Finally we discuss issues of genotype-phenotype correlations in GD.

CD40 C/T-1 polymorphism plays different roles in Graves' disease and Hashimoto's thyroiditis: a meta-analysis

CD40 plays a pathogenic role in various autoimmune diseases. However, studies investigating the association between CD40 C/T-1 polymorphism and autoimmune thyroid diseases risk have reported conflicting results and their relative population effect remains unclear; therefore, a meta-analysis was conducted. The data for this meta-analysis included 14 (4214 cases and 3851 controls) and 4 studies (623 cases and 774 controls) for the association of the CD40 C/T-1 polymorphism with Graves' disease (GD) and Hashimoto's thyroiditis (HT), respectively. Results suggested significant association for CD40 C/T-1 polymorphism (odds ratio 1.267 per C allele, p = 0.000) with GD but without HT. The individuals who carried the C/C or C/T genotype have significantly increased GD risk compared with those who carried T/T genotype (C/C vs. T/T: OR = 1.596, 95% CI, 1.256~2.028; C/T vs. T/T: OR = 1.210, 95% CI, 1.032~1.419; dominant model: OR = 1.366, 95% CI, 1.175~1.587; recessive model: OR = 1.322, 95% CI, 1.147~1.523), while no association was observed in HT. When stratified by ethnicity, the significant association between polymorphism and GD risk of Caucasians was found only in recessive models; but that of Asians was found in all models. In the subgroup analysis of study design, we found thyroid antibody status should be ascertained in controls and euthyroidism subjects with higher levels of thyroid antibody should be excluded from control and included into HT to avoid bias. Our meta-analysis showed that CD40 C/T-1 polymorphism plays different roles in GD and HT. Further studies will be needed to confirm our findings.