Role of Different CD40 Polymorphisms in Graves' Disease and Hashimoto's Thyroiditis

A Review of Testing for Distinguishing Hashimoto's Thyroiditis in the Hyperthyroid Stage and Grave's Disease

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are two very common autoimmune thyroid diseases (AITD). In this review, we use "HT in the hyperthyroidism stage" to refer to early HT with clinical manifestations of hyperthyroidism. In clinical practice, it is not easy to distinguish between HT in the hyperthyroidism stage and GD as they exhibit very similar clinical symptoms. The current literature lacks so far studies that systematically compare and summarize hyperthyroidism due to HT and GD from varied aspects. It is necessary to focus on all the clinical indices of HT in the hyperthyroidism stage and GD, for accurate diagnosis. Multiple databases such as PubMed, CNKI, WF Data, and CQVIP Data were used to search the literature concerning HT in the hyperthyroidism stage and GD. The information extracted from the relevant literature was summarized and further analyzed. To differentially diagnose hyperthyroidism as HT or GD, it is recommended to first focus on serological tests, followed by imaging tests, as well as the thyroid I131 uptake index. In pathology, fine needle aspiration cytology (FNAC) is the gold standard for the differential diagnosis of HT and GD. Test results from cellular immunology and genetics could also be used to accurately diagnose between the two diseases, which may be further developed and studied in the future. In this paper, we reviewed and summarized the difference between HT in the hyperthyroidism stage and GD from the following six aspects: blood tests, imaging, thyroid I131 uptake, pathology, cellular immunology, and genetics.

Molecular Mechanisms in Autoimmune Thyroid Disease

The most common cause of acquired thyroid dysfunction is autoimmune thyroid disease, which is an organ-specific autoimmune disease with two presentation phenotypes: hyperthyroidism (Graves-Basedow disease) and hypothyroidism (Hashimoto’s thyroiditis). Hashimoto’s thyroiditis is distinguished by the presence of autoantibodies against thyroid peroxidase and thyroglobulin. Meanwhile, autoantibodies against the TSH receptor have been found in Graves-Basedow disease. Numerous susceptibility genes, as well as epigenetic and environmental factors, contribute to the pathogenesis of both diseases. This review summarizes the most common genetic, epigenetic, and environmental mechanisms involved in autoimmune thyroid disease.

Clinical effect of methimazole combined with selenium in the treatment of toxic diffuse goiter in children

BACKGROUND

The incidence of toxic diffuse goiter (Graves’ disease) is higher in adolescents and preschool-aged children, with an upward trend. The incidence at 6–13 years of age is approximately 11.0%, and the incidences in men and women are 7.8% and 14.3%, respectively.

AIM

To explore the clinical effect of methimazole combined with selenium in the treatment of toxic diffuse goiter (Graves’ disease) in children and its effect on serum anti-thyroglobulin antibody (TRAb) and anti-thyroid peroxidase antibody (TPOAb).

METHODS

A total of 103 children with Graves’ disease treated in our hospital from January 2018 to June 2021 were divided into a traditional group and a combined group (15-20 mg methimazole orally given to children) and a combined group (50 µg selenium added on the basis of traditional treatment) according to different treatment methods to explore the therapeutic effects of the two methods and to observe the changes in thyroid volume and serum TRAb, TPOAb, free thyroxine (FT4) and inflammatory factor levels before and after treatment. The time taken for FT4 to return to normal was compared between the two groups.

RESULTS

Treatment was significantly more effective in the combined group than in the traditional group (P < 0.05). The thyroid volumes of the children in the two groups was measured before and after treatment. Thyroid volume decreased significantly after treatment in both groups, and the thyroid volume was significantly lower in the combined group than in the traditional group (P < 0.05). The serum levels of interleukin-6 (IL-6), IL-8, TRAb, TPOAb and FT4 in the two groups were detected before and after treatment. The levels of IL-6, IL-8, TRAb, TPOAb and FT4 were significantly lower in the combined group than in the traditional group (P < 0.05). Follow-up of the children in the two groups showed that compared with the traditional group, it took less time for children in the combined group to return to the normal level (P < 0.05).

CONCLUSION

Methimazole combined with selenium can effectively treat Graves’ disease in children, reduce the expression of TRAb, TPOAb, FT4 and inflammatory factors, and improve the curative effect. Thus, the combined treatment warrants further clinical research.

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.

Genetic Susceptibility to Joint Occurrence of Polycystic Ovary Syndrome and Hashimoto's Thyroiditis: How Far Is Our Understanding?

Polycystic ovary syndrome (PCOS) and Hashimoto’s thyroiditis (HT) are endocrine disorders that commonly occur among young women. A higher prevalence of HT in women with PCOS, relative to healthy individuals, is observed consistently. Combined occurrence of both diseases is associated with a higher risk of severe metabolic and reproductive complications. Genetic factors strongly impact the pathogenesis of both PCOS and HT and several susceptibility loci associated with a higher risk of both disorders have been identified. Furthermore, some candidate gene polymorphisms are thought to be functionally relevant; however, few genetic variants are proposed to be causally associated with the incidence of both disorders together.

Compelling Evidence Linking CD40 Gene With Graves' Disease in the Chinese Han Population

Mutations in CD40 have been widely reported to be risk factors for Graves' disease (GD). The gene, along with its cognate ligand CD40L, may regulate pro-inflammatory and immune responses. Rs1883832, located at the -1 position of the Kozak sequence, is the most well-studied single nucleotide polymorphism (SNP) of CD40, and has been confirmed to predispose those with the alteration to GD, regardless of ethnicity. Our genome-wide association study (GWAS) indicated that several SNPs, including rs1883832 located within the vicinity of CD40 were associated with GD in the Han Chinese population. Aiming at identifying the most consequential SNP and its underlying pathogenic mechanism, we performed a two-stage refined study on 8,171 patients with GD and 7,906 controls, and found rs1883832 was the most significantly GD-associated SNP in the CD40 gene region (P_Combined = 9.17×10^-11, OR = 1.18). Through searching the cis-expression quantitative trait locus database and using quantitative RT-PCR, we further discovered that the rs1883832 genotype can influence CD40 gene transcription. Furthermore, we demonstrated that rs1883832 is a susceptibility locus for pTRAb+ GD patients. In conclusion, the current study provides robust evidence that rs1883832 can regulate CD40 gene expression and affect serum TRAb levels, which ultimately contributes to the development of GD.

A Novel Anti-CD40 Monoclonal Antibody, Iscalimab, for Control of Graves Hyperthyroidism-A Proof-of-Concept Trial

CONTEXT

The CD40-CD154 co-stimulatory pathway plays an important role in the pathogenesis of Graves disease (GD) by promoting autoreactive B-cell activation.

OBJECTIVE

Evaluate efficacy and safety of a human, blocking, nondepleting anti-CD40 monoclonal antibody, iscalimab, in hyperthyroid patients with GD.

DESIGN

Open-label, phase II proof-of-concept study.

SETTING

Multicenter.

PATIENTS

Fifteen with GD.

INTERVENTION

Patients received 5 doses of iscalimab at 10 mg/kg intravenously over 12 weeks.

MAIN OUTCOME MEASURES

Thyroid-related hormones and autoantibodies, plasma soluble CD40, free CD40 on B cells, soluble CXCL13, pharmacokinetics, and safety were assessed.

RESULTS

The iscalimab intervention resulted in complete CD40 engagement for up to 20 weeks. A clinical response and biochemical euthyroidism was observed in 7 of 15 (47%) patients. Free and total triiodothyronine and thyroxine normalized in 7 patients who did not receive any rescue medication with antithyroid drugs (ATD), and 2/15 (13.3%) showed normal thyrotropin. Six (40%) patients required ATD. Four of 7 responders relapsed after treatment completion. Serum concentrations of thyrotropin receptor autoantibodies (TSH-R-Ab) significantly declined in all patients (mean 15.3 IU/L vs 4.0 IU/L, 66% reduction; P < 0.001) and TSH-R-Ab levels normalized in 4 (27%). Thyroperoxidase and thyroglobulin autoantibodies significantly decreased in responders. Iscalimab rapidly reduced serum CXCL13 concentrations (P < 0.001). Twelve (80.0%) patients reported at least 1 adverse event (AE). All treatment-related AE were mild or moderate and resolved by end of the study.

CONCLUSION

Iscalimab was generally safe and clinically effective in a subgroup of hyperthyroid GD patients. The potential therapeutic benefit of iscalimab should be further tested.

Association of soluble CD40 levels with -1 C > T CD40 polymorphism and chronic kidney disease in systemic lupus erythematosus

Background

CD40 is a transmembrane protein mainly expressed on the antigen‐presenting cells surface. CD40 plays a crucial role in immunoglobulin class switching and antibodies production. Genetic polymorphisms in the CD40 gene have been associated with increased risk of systemic lupus erythematosus (SLE) in several populations. This study aimed to evaluate the association of CD40 polymorphisms (−1 C > T, rs1883832 and 6,048 G > T, rs4810485) with SLE susceptibility, as well as with mRNA expression and soluble CD40 (sCD40) levels.

Methods

The study included 293 patients with SLE and 294 control subjects (CS). Genotyping was performed by PCR‐RFLP method. CD40 mRNA expression was determined by quantitative real‐time PCR, and ELISA quantified sCD40 levels.

Results

The CD40 polymorphisms −1 C > T and 6,048 G > T were associated with SLE susceptibility. There was no difference between CD40 mRNA expression and CD40 polymorphisms. The sCD40 levels were lower in SLE patients with TT haplotype, whereas higher sCD40 levels were associated with damage and impaired renal function according to SLICC and KDIGO. The sCD40 levels were negatively correlated with eGFR.

Conclusion

The CD40 gene polymorphisms increase the risk of SLE in the western Mexican population. The sCD40 levels are associated with −1 C > T polymorphism and chronic kidney disease.

Update on the clinical assessment and management of thyroid eye disease

PURPOSE OF REVIEW

To offer an update on advances and controversies in the assessment, investigation and treatment of thyroid eye disease (TED), a disfiguring orbital autoimmune disease, which can manifest with diplopia and threaten not only sight - but also life.

RECENT FINDINGS

Developments in biomarkers and imaging are helping to tailor the management of patients. Emerging therapies target different pathways in the disease and are informed by studies into TED pathogenesis: the last 2 years has, for example, seen the culmination of a two-decade long bench-to-bedside story in which an original focus on the IGF1 receptor has translated into an effective treatment for proptosis in thyroid eye disease. Whether this will result in a real-world reduction in TED-related morbidity will depend on access; commercial pricing decisions may preclude widespread adoption of novel therapies.

SUMMARY

Thyroid eye disease research is enjoying a renaissance with advances in both monitoring and treatment coupled with a renewed emphasis on a holisitic approach, which includes aesthetic care for patients; this is perhaps the most exciting time to be part of the international thyroid eye disease community in decades - for physicians, surgeons and patients. The commercial window for break-through drugs are narrowing with an array of new therapeutic agents in the pipeline over the coming decade.

Insulin-like Growth Factor-I Receptor and Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a complex disease process presumed to emerge from autoimmunity occurring in the thyroid gland, most frequently in Graves disease (GD). It is disfiguring and potentially blinding, culminating in orbital tissue remodeling and disruption of function of structures adjacent to the eye. There are currently no medical therapies proven capable of altering the clinical outcome of TAO in randomized, placebo-controlled multicenter trials. The orbital fibroblast represents the central target for immune reactivity. Recent identification of fibroblasts that putatively originate in the bone marrow as monocyte progenitors provides a plausible explanation for why antigens, the expressions of which were once considered restricted to the thyroid, are detected in the TAO orbit. These cells, known as fibrocytes, express relatively high levels of functional TSH receptor (TSHR) through which they can be activated by TSH and the GD-specific pathogenic antibodies that underpin thyroid overactivity. Fibrocytes also express insulin-like growth factor I receptor (IGF-IR) with which TSHR forms a physical and functional signaling complex. Notably, inhibition of IGF-IR activity results in the attenuation of signaling initiated at either receptor. Some studies suggest that IGF-IR-activating antibodies are generated in GD, whereas others refute this concept. These observations served as the rationale for implementing a recently completed therapeutic trial of teprotumumab, a monoclonal inhibitory antibody targeting IGF-IR in TAO. Results of that trial in active, moderate to severe disease revealed dramatic and rapid reductions in disease activity and severity. The targeting of IGF-IR with specific biologic agents may represent a paradigm shift in the therapy of TAO.

IRF7 Gene Variations Confer Susceptibility to Autoimmune Thyroid Diseases and Graves' Ophthalmopathy

The objective of this study was to investigate whether IRF7 polymorphisms are associated with autoimmune thyroid diseases (AITDs). We selected three single nucleotide polymorphisms (SNPs) of IRF7, namely, rs1061501, rs1131665, and rs1061502 for genotyping using PCR-based ligase detection reaction (LDR) method in a total of 1659 participants (592 with Graves' disease, 297 with Hashimoto's thyroiditis, and 770 healthy controls). Gene-disease and genotype-clinical phenotype associations were evaluated for the three SNPs. Our results showed that the AG genotype and the minor allele G frequency of rs1131665 and rs1061502 in AITD patients were both higher than those of the controls (rs1131665: AG genotype: P = 0.017, OR = 1.968; allele G: P = 0.018, OR = 1.946; rs1061502: AG genotype: P = 0.029, OR = 1.866; allele G: P = 0.031, OR = 1.847). Subgroup analysis also showed that the AG genotype and the minor allele G frequency of rs1131665 and rs1061502 in Graves' disease patients were both higher than those of the controls (rs1131665: AG genotype: P = 0.015, OR = 2.074; allele G: P = 0.016, OR = 2.048; rs1061502: AG genotype: P = 0.034, OR = 1.919; allele G: P = 0.035, OR = 1.898). Furthermore, the allele G frequency of rs1061501 was associated with Graves' ophthalmopathy (P = 0.035, OR = 1.396). No significant difference in IRF7 polymorphisms was found between Hashimoto's thyroiditis patients and controls. Our study has revealed for the first time that IRF7 is a susceptibility gene for AITD, especially for Graves' disease and Graves' ophthalmopathy.

Correlation of TSHR and CTLA-4 Single Nucleotide Polymorphisms with Graves Disease

This study was designed to explore the association between Graves disease (GD) and thyroid-stimulating hormone receptor (TSHR) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) single nucleotide polymorphisms (SNPs). We studied a total of 1217 subjects from a Han population in northern Anhui province in China. Six SNPs within TSHR (rs179247, rs12101261, rs2284722, rs4903964, rs2300525, and rs17111394) and four SNPs within CTLA-4 (rs10197319, rs231726, rs231804, and rs1024161) were genotyped via a Taqman probe technique using a Fluidigm EP1 platform. The TSHR alleles rs179247-G, rs12101261-C, and rs4903964-G were negatively correlated with GD, whereas the rs2284722-A and rs17111394-C alleles were positively correlated with GD. Analyzing TSHR SNPs at rs179247, rs2284722, rs12101261, and rs4903964 yielded 8 different haplotypes. There were positive correlations between GD risk and the haplotypes AGTA and AATA (OR = 1.27, 95%CI = 1.07-1.50, P = 0.005; OR = 1.45, 95%CI = 1.21-1.75, P < 0.001, respectively). There were negative correlations between GD risk and the haplotype GGCG (OR = 0.56, 95%CI = 0.46-0.67, P < 0.001). With respect to haplotypes based on SNPs at the TSHR rs2300525 and rs17111394 loci, the CC haplotype was positively correlated with GD risk (OR = 1.32, 95%CI = 1.08-1.60, P = 0.006). Analyzing CTLA-4 SNPs at rs231804, rs1024161, and rs231726 yielded four haplotypes, of which AAA was positively correlated with GD risk (OR = 1.21, 95%CI = 1.02-1.43, P = 0.029). Polymorphisms at rs179247, rs12101261, rs2284722, rs4903964, and rs17111394 were associated with GD susceptibility. Haplotypes of both TSHR and CTLA-4 were additionally related to GD risk.

Variations in CD14 Gene Are Associated With Autoimmune Thyroid Diseases in the Chinese Population

Autoimmune thyroid diseases (AITDs) are chronic organ-specific autoimmune diseases and mainly include Graves' disease (GD) and Hashimoto's thyroiditis (HT). CD14 is an important component of the immune system as a receptor for gram-negative lipopolysaccharide (LPS). The genetic polymorphisms of CD14 have been confirmed to be associated with a variety of autoimmune diseases. However, its relationship with AITDs is still unclear. The study was aimed to determine whether four single nucleotide polymorphisms (rs2915863, rs2569190, rs2569192, and rs2563298) of CD14 are associated with AITDs and its subgroups of GD and HT. The results showed significant association of rs2915863 and rs2569190 with GD. The frequencies of rs2915863 genotypes and T allele in patients with GD differed significantly from their controls (P = 0.007 and P = 0.021, respectively). For rs2569190, frequencies of genotypes and G allele in GD patients also showed positive P-values (P = 0.038 and P = 0.027, respectively). The correlations between these two loci and GD are more pronounced in female GD patients and patients with a family history. In genetic model analysis, the allele model, recessive model, and homozygous model of rs2569190 and rs2915863 embodied strong correlations with GD after the adjusting of age and gender (P = 0.014, P = 0.015, P = 0.009, and P = 0.014, P = 0.001, P = 0.006, respectively). However, these four sites are not related to HT. We firstly discovered the relationship between CD14 gene polymorphism and GD, and the results indicate that CD14 is an important risk locus for AITD and its SNPs may contribute to host's genetic predisposition to GD.