The association of CTLA4 polymorphism with type 1 diabetes is concentrated in patients complicated with autoimmune thyroid disease: a multicenter collaborative study in Japan

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.

Combined Hypophysitis and Type 1 Diabetes Mellitus Related to Immune Checkpoint Inhibitors

Context

The occurrence of multiple endocrinopathies due to immune checkpoint inhibitors (ICIs) is a relatively common adverse event. However, the occurrence of a combination of hypophysitis and type 1 diabetes mellitus (T1DM) is extremely rare, and its clinical features are unclear.

Objective

We comparatively analyzed the clinical features of this combination and each individual ICI-induced endocrinopathy.

Methods

We reported 3 cases that we encountered and reviewed previously reported cases of patients with combined hypophysitis and T1DM due to ICIs.

Results

Anti-programmed cell death-1 (anti-PD-1) antibodies were prescribed to all 3 cases. The duration from ICI initiation to the onset of endocrine disease was 12 to 48 weeks. Several human leukocyte antigen (HLA) haplotypes that have disease susceptibility to hypophysitis were detected in all 3 patients. With the 17 previously reported cases, combined endocrinopathies were more common in men (85%). The onset age was in the 60s for both combined and single endocrinopathies. Anti-PD-1 antibodies were used in most of the cases (90%). The time from ICI initiation to the onset of endocrinopathies was 24 (8-76) weeks for hypophysitis and 32 (8-76) weeks for T1DM in patients with combined endocrinopathies, which was not significantly different from that for each single endocrinopathy.

Conclusion

We presented 3 cases of patients with combined endocrinopathies of hypophysitis and T1DM that may have been caused by anti-PD-1 antibodies. There was no difference in the time from ICI initiation to the onset of endocrinopathies between combined and single endocrinopathies. Further case accumulation and pathogenic investigations are required.

Insights Into the Host Contribution of Endocrine Associated Immune-Related Adverse Events to Immune Checkpoint Inhibition Therapy

Blockade of immune checkpoints transformed the paradigm of systemic cancer therapy, enabling substitution of a cytotoxic chemotherapy backbone to one of immunostimulation in many settings. Invigorating host immune cells against tumor neo-antigens, however, can induce severe autoimmune toxicity which in many cases requires ongoing management. Many immune-related adverse events (irAEs) are clinically and pathologically indistinguishable from inborn errors of immunity arising from genetic polymorphisms of immune checkpoint genes, suggesting a possible shared driver for both conditions. Many endocrine irAEs, for example, have analogous primary genetic conditions with varied penetrance and severity despite consistent genetic change. This is akin to onset of irAEs in response to immune checkpoint inhibitors (ICIs), which vary in timing, severity and nature despite a consistent drug target. Host contribution to ICI response and irAEs, particularly those of endocrine origin, such as thyroiditis, hypophysitis, adrenalitis and diabetes mellitus, remains poorly defined. Improved understanding of host factors contributing to ICI outcomes is essential for tailoring care to an individual’s unique genetic predisposition to response and toxicity, and are discussed in detail in this review.

Genetics of fulminant type 1 diabetes

Since fulminant type 1 diabetes was reported as a distinct subtype of type 1 diabetes in 2000, the Committee on Type 1 diabetes, Japan Diabetes Society has continuously recruited patients and conducted genomic research to elucidate the genetic basis of fulminant type 1 diabetes. The contribution of the human leukocyte antigen complex (HLA) to genetic susceptibility to fulminant type 1 diabetes was compared with that of other subtypes in 2009. The alleles and haplotypes associated with fulminant type 1 diabetes were found to be different from acute-onset and slowly progressive type 1 diabetes. DRB1*15:01-DQB1*06:02, a protective haplotype against acute-onset type 1 diabetes, does not provide protection against fulminant type 1 diabetes and DRB1*08:02-DQB1*03:02, a susceptible haplotype to acute-onset type 1 diabetes, does not confer susceptibility to fulminant type 1 diabetes. Recently, the first genome-wide association study (GWAS) of fulminant type 1 diabetes was performed in Japanese individuals. A strong association was observed with multiple single nucleotide polymorphisms (SNPs) in the HLA region, and the strongest association was observed with rs9268853 in the class II DR region. In addition, 11 SNPs outside the HLA region showed some evidence of association with the disease. In particular, rs11170445 in CSAD/lnc-ITGB7-1 on chromosome 12q13.13 showed an association at a genome-wide significance level. Fine mapping revealed that rs3782151 in CSAD/lnc-ITGB7-1 showed the lowest P value. CSAD/lnc-ITGB7-1 was found to be strongly associated with susceptibility to fulminant, but not classical, autoimmune type 1 diabetes, implicating this locus in the distinct phenotype of fulminant type 1 diabetes.

Simultaneous development of Graves' disease and type 1 diabetes during anti-programmed cell death-1 therapy: A case report

We present the first case of simultaneous development of Graves' disease and type 1 diabetes during anti-programmed cell death 1 therapy. A 48-year-old man with parotid gland adenocarcinoma and lung metastasis had received five courses of nivolumab. Fourteen days after administration of the sixth course, his casual plasma glucose and hemoglobin A1c levels were 379 mg/dL and 7.2%, respectively. Furthermore, thyrotoxicosis was detected with a blood test. Serum total ketone body and thyroid-stimulating hormone receptor antibody levels increased, and serum C-peptide level decreased to 0.01 ng/mL thereafter. Thus, we concluded that he simultaneously developed anti-programmed cell death 1 therapy-associated type 1 diabetes and Graves' disease. Among Japanese patients with autoimmune polyglandular syndrome type III, the frequency of human leukocyte antigen-DRB1*04:05 is higher in those with both type 1 diabetes and Graves' disease. Our case had human leukocyte antigen-DRB1*04:05, which might be associated with the simultaneous development of the two diseases.

Autoimmune thyroid disease and type 1 diabetes mellitus: same pathogenesis; new perspective?

Autoimmune thyroid disease (AITD) and type 1 diabetes mellitus (T1DM) are two common autoimmune diseases that can occur concomitantly. In general, patients with diabetes have a high risk of AITD. It has been proposed that a complex genetic basis together with multiple nongenetic factors make a variable contribution to the pathogenesis of T1DM and AITD. In this paper, we summarize current knowledge in the field regarding potential pathogenic factors of T1DM and AITD, including human leukocyte antigen, autoimmune regulator, lymphoid protein tyrosine phosphatase, forkhead box protein P3, cytotoxic T lymphocyte-associated antigen, infection, vitamin D deficiency, and chemokine (C-X-C motif) ligand. These findings offer an insight into future immunotherapy for autoimmune diseases.

Endocrine Toxicity of Cancer Immunotherapy Targeting Immune Checkpoints

Immune checkpoints are small molecules expressed by immune cells that play critical roles in maintaining immune homeostasis. Targeting the immune checkpoints cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD-1) with inhibitory antibodies has demonstrated effective and durable antitumor activity in subgroups of patients with cancer. The US Food and Drug Administration has approved several immune checkpoint inhibitors (ICPis) for the treatment of a broad spectrum of malignancies. Endocrinopathies have emerged as one of the most common immune-related adverse events (irAEs) of ICPi therapy. Hypophysitis, thyroid dysfunction, insulin-deficient diabetes mellitus, and primary adrenal insufficiency have been reported as irAEs due to ICPi therapy. Hypophysitis is particularly associated with anti-CTLA-4 therapy, whereas thyroid dysfunction is particularly associated with anti-PD-1 therapy. Diabetes mellitus and primary adrenal insufficiency are rare endocrine toxicities associated with ICPi therapy but can be life-threatening if not promptly recognized and treated. Notably, combination anti-CTLA-4 and anti-PD-1 therapy is associated with the highest incidence of ICPi-related endocrinopathies. The precise mechanisms underlying these endocrine irAEs remain to be elucidated. Most ICPi-related endocrinopathies occur within 12 weeks after the initiation of ICPi therapy, but several have been reported to develop several months to years after ICPi initiation. Some ICPi-related endocrinopathies may resolve spontaneously, but others, such as central adrenal insufficiency and primary hypothyroidism, appear to be persistent in most cases. The mainstay of management of ICPi-related endocrinopathies is hormone replacement and symptom control. Further studies are needed to determine (i) whether high-dose corticosteroids in the treatment of ICPi-related endocrinopathies preserves endocrine function (especially in hypophysitis), and (ii) whether the development of ICPi-related endocrinopathies correlates with tumor response to ICPi therapy.

Slowly Progressive Type 1 Diabetes Mellitus: Current Knowledge And Future Perspectives

Slowly progressive type 1 insulin-dependent diabetes mellitus (SPIDDM), sometimes referred to as latent autoimmune diabetes in adults (LADA), is a heterogeneous disease that is often confused with type 1 and type 2 diabetes. As a result, there were few diagnostic criteria for this disorder until 2012, when the Japan Diabetes Society established criteria that could be used in clinical practice. A primary question is whether pathologic markers for type 1 or type 2 diabetes are present in the pancreas of patients with SPIDDM, because the phenotype of SPIDDM is similar to both type 1 and type 2 diabetes. Recent studies clarified pathologic findings in the pancreas of patients with SPIDDM, which included T-cell-mediated insulitis, a marker of type 1 diabetes; pseudoatrophic islets (islets specifically devoid of beta cells), another hallmark of type 1 diabetes; and a lack of amylin (ie, islet amyloid polypeptide) deposition to the islet cells, a pathologic marker of type 2 diabetes. In terms of preventing the loss of beta-cell function in patients with SPIDDM, several studies have shown that some drugs, including dipeptidyl peptidase-4 inhibitors, are effective. There is an increased need for early diagnosis of SPIDDM to preserve beta-cell function. This review presents updated findings on the pathogenesis and immunologic findings of the affected pancreas, diagnostic markers, risk factors for progression of beta-cell dysfunction, epidemiology, clinical features, diagnostic strategies, prevention strategies, and clinical options for patients with SPIDDM.

Phenotypic Expression of Autoimmunity in Children With Autoimmune Thyroid Disorders

Autoimmune thyroid diseases (AITDs), including Hashimoto's thyroiditis (HT) and Graves' disease (GD), tend to aggregate with other non-thyroidal autoimmune diseases (NTADs). Aim of this Mini-review is to report the most recent insights concerning the clustering of NTADs in pediatric patients with either HT or GD, the pathophysiology of AITDs and the metamorphic thyroid autoimmunity. A systematic literature research of the last 15 years, according to EQUATOR statement, was carried out through MEDLINE via PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) Embase, CINAHL, Cochrane Library, based on the following keywords: (autoimmune thyroid disease OR Hashimoto thyroiditis OR Grave's disease) AND (autoimmune comorbidities OR extra-thyroidal autoimmune disorders) AND (children OR adolescents OR pediatrics) AND (celiac disease OR type 1 diabetes mellitus OR arthropathies OR cutaneous diseases) AND (Turner syndrome OR Down syndrome). One-hundred and twenty-eight manuscripts were extrapolated but only seventeen were eligible. On the basis of the available reports it may be inferred that clustering of NTADs can be significantly modified by both patients' age at AITDs presentation and association with Down's syndrome (DS). Particularly, the association of AITDs with celiac disease and type 1 diabetes was most commonly reported in children than in adults. A sequential shifting from HT to GD has been described in children with AITDs, and it seems to be more frequent in children with DS than in those without DS. Coexistence of autoimmune diseases might be the result of a complex interaction among genetics, environment and epigenetic modifications that are able to affect gene expression, immune system response and, finally, the pathogenesis of autoimmune diseases.

Genetic differences between type 1 diabetes with and without other autoimmune diseases

BACKGROUND

Clusters of autoimmune diseases (ADs) are present in some people with type 1 diabetes. This clustering suggests the existence of common genetic backgrounds for abnormal autoimmunity in these individuals. However, the genetic differences between type 1 diabetes patients with and without other ADs are not well known.

METHODS

To investigate the clinical background and genetic differences between type 1 diabetes patients with and without other ADs, single nucleotide polymorphisms (SNPs) in the CTLA4, SUMO4, PTPN22, IRF5, STAT4, and BLK genes were analysed by using either a TaqMan assay or direct sequencing. The frequencies of alleles, genotypes of each gene, and the human leukocyte antigen (HLA) haplotype were analysed to investigate differences among 3 groups: type 1 diabetes with systemic ADs (group A), type 1 diabetes with other organ-specific ADs (group B), and type 1 diabetes without other ADs (group C).

RESULTS

The frequency of the C allele in the -1123G > C SNP in the PTPN22 gene promoter was significantly higher in groups A and B than in group C (P = .0258 and .0207, respectively). The allele frequencies of the other SNPs were comparable. The frequency of HLA DRB1*0405-DQB1*0401 was significantly higher in groups A and B than in group C (P = .021 and .0395, respectively).

CONCLUSIONS

The -1123G > C SNP in the PTPN22 gene promoter and HLA DRB1*0405-DQB1*0401 might influence the concurrence of systemic and organ-specific ADs in patients with type 1 diabetes.

Hypothyroidism among pediatric patients with type 1 diabetes mellitus, from patients' characteristics to disease severity

We performed this study to evaluate the associations of hypothyroidism with clinical severity and the occurrence of diabetic ketoacidosis (DKA) at initial diagnosis among pediatric patients with type 1 diabetes mellitus (T1DM). 330 children with T1DM who referred to Diabetes Clinic were enrolled. The medical records were e valuated and a blood sample was drawn from patients for measuring thyroid function and antibodies, blood glucose, and glycated hemoglobin (HbA1C) levels. Hypothyroidism was detected in 9.6% of children with T1DM and was associated with higher rates of DKA (OR = 3.15, 95%CI = 1.48–6.71) and younger age at initial diagnosis (7.3 ± 3.2 vs. 10.1 ± 2.5, p = 0.04), higher levels of HbA1C upon enrolment (9.8 ± 2.2 vs. 8.8 ± 1.9, p = 0.02) and the requirement for higher insulin doses to control the disease (0.9 ± 0.42 vs. 0.81 ± 0.2, p = 0.03) compared to children with T1DM and normal thyroid function. Additionally children with T1DM and hypothyroidism had significantly higher rates of anti-TPO antibodies (p < 0.001), consanguinity in their parents (p =0.01), and family history of diabetes mellitus (p = 0.02) in their first degree relatives. In conclusion autoimmune hypothyroidism is prevalent among children with T1DM and is associated with a more aggressive disease at initial presentation, poorly controlled T1DM, and requirement for higher Insulin doses for controlling the disease.

Immune checkpoint therapy and type 1 diabetes

Type 1 diabetes is caused by destruction of insulin-producing beta cells of the pancreas. The etiology of type 1 diabetes is immune-mediated by either an organ-specific autoimmune mechanism in autoimmune type 1 diabetes or a still unknown but probably immune-mediated mechanism in fulminant type 1 diabetes. Immunomodulation is therefore expected to accelerate or inhibit type 1 diabetes. Recent progress in anti-cancer therapy by immune-checkpoint blockade, such as anti-PD-1 and anti-CTLA4 monoclonal antibodies, has markedly improved the prognosis of patients with advanced cancers. These drugs activate anti-tumor immunity by blocking inhibitory signals of T lymphocytes. Activation of immunological pathways, however, is expected to accelerate immune-mediated diseases. In fact, the development of autoimmune-thyroid diseases and type 1 diabetes, including fulminant type 1 diabetes, has been reported in patients treated with immune checkpoint blockers. The development of fulminant type 1 diabetes is a major concern because of its abrupt onset and very rapid progression, leading to death unless proper treatment is initiated immediately after diagnosis. In this review, the development of type 1 diabetes with immune-checkpoint therapy and its etiological background are discussed.

Thyroid Disease Is Prevalent and Predicts Survival in Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND

A significant minority of patients with idiopathic pulmonary fibrosis (IPF) display features of autoimmunity without meeting the criteria for overt connective tissue disease. A link between IPF and other immune-mediated processes, such as hypothyroidism (HT), has not been reported. In this investigation, we aimed to determine whether HT is associated with IPF and if outcomes differ between patients with IPF with and without HT.

METHODS

A retrospective case-control analysis was conducted. Of 311 patients referred to the University of Chicago Interstitial Lung Disease Center with an initial diagnosis of IPF, 196 met the inclusion criteria and were included in the final analysis. Each case was matched 1:1 by age, sex, and race to a control subject with COPD.

RESULTS

HT was identified in 16.8% of cases and 7.1% of control subjects (OR, 2.7; 95% CI, 1.31-5.54; P = .01). Among patients with IPF, HT was associated with reduced survival time (P < .001) and was found to be an independent predictor of mortality in multivariable Cox regression analysis (hazard ratio, 2.12; 95% CI, 1.31-3.43; P = .002). A secondary analysis of two IPF clinical trial datasets supports these findings.

CONCLUSIONS

HT is common among patients with IPF, with a higher prevalence than in those with COPD and the general population. The presence of HT also predicts mortality in IPF, a finding that may improve future prognostication models. More research is needed to determine the biologic link between IPF and HT and how the presence of thyroid disease may influence disease progression.

The association of cytotoxic T-lymphocyte antigen-4 + 49A/G and CT60 polymorphisms with type 1 diabetes and latent autoimmune diabetes in Chinese adults

OBJECTIVE

The aim of this study was to investigate the association of cytotoxic T-lymphocyte antigen-4 (CTLA-4) + 49A/G and CT60 polymorphisms with latent autoimmune diabetes in adults (LADA) and the genetic differences between LADA, type 1 diabetes (T1DM), and type 2 diabetes (T2DM) in a Chinese population.

SUBJECTS

A total of 231 LADA, 402 T1DM, and 330 T2DM patients as well as 482 nondiabetic controls were recruited in the study.

METHODS

CTLA-4 + 49A/G and CT60 polymorphisms were analyzed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The level of glutamic acid decarboxylase antibodies (GADAs) was detected by a radioligand binding assay.

RESULTS

The CTLA-4 + 49A/G risk genotype GG was most frequent in T1DM patients (45.3%), followed by LADA patients (44.2%) and T2DM patients (38.8%). Significantly higher frequencies of the risk genotype GG were observed in the T1DM (OR = 1.532, 95% CI 1.168-2.010, P = 0.002) and LADA patients (OR = 1.464, 95% CI 1.063-2.017, P = 0.019). The frequencies of the CTLA-4 CT60 risk genotype GG were 65.2, 61.9, 58.5, and 56.4% in the T1DM, LADA, T2DM, and control groups, respectively. The CTLA-4 CT60 GG risk genotypes were only associated with T1DM (OR = 1.445, 95% CI 1.1-1.898, P = 0.008). Compared with controls, patients having a high titer of GADA (GADA ≥ 180 IU/ml) had higher frequencies of the GG risk genotype of CTLA-4 + 49 A/G (49.4% vs. 35.1% OR = 1.807, 95% CI 1.125-2.903, P = 0.014), but there was no difference between patients having a low titer of GADA and controls.

CONCLUSION

The CTLA-4 + 49 A/G polymorphism confers genetic susceptibility to LADA and T1DM, while the CTLA-4 CT60 polymorphism is only associated with T1DM in Chinese population. The CTLA-4 + 49 A/G genotype distribution in LADA is associated with the GADA level.

Allelic variant in CTLA4 is associated with thyroid failure and faster β-cell exhaustion in latent autoimmune diabetes in adults

BACKGROUND

The aim of the study was to investigate the role of the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) G6230A variant on the susceptibility of latent autoimmune diabetes in adults (LADA) as a whole and in the subset of patients who share autoimmune thyroid disease (AITD).

METHODS

The study included 202 LADA, 1373 patients with early onset type 1 diabetes (T1D), 130 patients with late-onset T1D, 188 patients with non-autoimmune diabetes and 1904 healthy controls. Thyrotropin (thyrotropin-stimulating hormone; TSH) and antibodies against thyroid peroxidase were analyzed in all patients. The CTLA4 G6230A variant was assessed in LADA, early and late-onset T1D patients as well as in the controls.

RESULTS

The frequency of CTLA4 G alleles and genotypes in LADA patients did not differ significantly from that in the other groups, regardless of its association with AITD. We found an increased frequency of G allele-containing genotypes within LADA patients who had higher TSH compared with those with normal TSH (P = 0.002). Moreover, LADA patients carrying G allele-containing genotypes were more likely to require insulin therapy within 4 years of diagnosis (P = 0.002).

CONCLUSIONS

The G6230A CTLA4 variant does not confer susceptibility to LADA in Sardinian patients even when associated with AITD. However, it helps identify a particular subset of LADA patients with more clinically severe disease, both for thyroid dysfunction and diabetes.

Dissecting the role of the FOXP3 gene in the joint genetic susceptibility to autoimmune thyroiditis and diabetes: a genetic and functional analysis

We have previously shown that a (TC)n microsatellite in intron 5 of the Forkhead Box Protein 3 (FOXP3) gene was associated with a variant of the autoimmune polyglandular syndrome type 3 (APS3v), that is defined as the co-occurrence of type 1 diabetes (T1D) and autoimmune thyroiditis (AITD). Allele 10, containing 25 repeats of the microsatellite (long repeats), is preferentially transmitted to offspring with APS3v, while allele 2, containing 14 repeats of the microsatellite (short repeats), is protective. We hypothesized that the long repeats of the intron 5 microsatellite decrease FOXP3 splicing and function, thereby reducing regulatory T cell activity and promoting the development of APS3v. We cloned genomic DNA from two males hemizygous for the long and short repeats of the microsatellite on their X-chromosomes and transfected them into human embryonic kidney 293 (HEK 293) cells to perform direct splicing analysis. We identified a novel splice variant of FOXP3 lacking exon 6, and showed that it is expressed in human thymus and lymph node. However, the length of the repeats in the microsatellite did not significantly influence the expression of this FOXP3 splice variant in vitro. Interestingly, this splice variant was expressed in human regulatory T cells, suggesting that it may play a role in their function. In conclusion, we identified a novel splice variant FOXP3Δ6. The role of its expression in regulatory T cells in the development of autoimmunity remains to be determined.

Genetics and pathogenesis of type 1 diabetes: prospects for prevention and intervention

Type 1 diabetes is etiologically a multifactorial disease caused by a complex interaction of genetic and environmental factors, with the former consisting of multiple susceptibility genes. Identification of genes conferring susceptibility to type 1 diabetes would clarify etiological pathways in the development and progression of type 1 diabetes, leading to the establishment of effective methods for prevention and intervention of the disease. Among multiple susceptibility genes, HLA and INS are particularly important because of their contribution to tissue specificity in the autoimmune process. DRB1*04:05-DQB1*04:01 is associated with autoimmune type 1 diabetes, idiopathic fulminant type 1 diabetes and anti-islet autoimmunity in autoimmune thyroid diseases, suggesting that this haplotype is associated with beta-cell specificity in autoimmune diseases. Genes involved in the expression of insulin in the thymus contribute to beta-cell-specific autoimmune mechanisms in type 1 diabetes. These genes and pathways are important targets for tissue-specific prevention and intervention of type 1 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00176.x, 2011).

Common variants on cytotoxic T lymphocyte antigen-4 polymorphisms contributes to type 1 diabetes susceptibility: evidence based on 58 studies

In the past decade, a number of case–control studies have been carried out to investigate the relationship between the CTLA4 gene polymorphisms and type 1 diabetes (T1D). However, these studies have yielded contradictory results. To investigate this inconsistency, we performed a meta-analysis of all available studies dealing with the relationship between the CTLA4 polymorphism and T1D. In total, 58 association studies on two CTLA4 polymorphisms (G49A and C60T) and risk of T1D, including a total of 30,723 T1D cases and 45,254 controls were included. In a combined analysis, the summary per-allele odds ratio (OR) for T1D of the G49A and C60T polymorphism was 1.42 [95% confidence interval (CI): 1.31–1.53, P<10⁻⁵] and 1.23 (95% CI: 1.18–1.29, P<10⁻⁵), respectively. Significant results were also observed using dominant or recessive genetic model. In the subgroup analysis by ethnicity and sample size, significantly increased risks were also found for these polymorphisms. This meta-analysis demonstrated that the G49A and C60T polymorphism of CTLA4 is a risk factor associated with increased T1D susceptibility, but these associations vary in different ethnic populations.

CTLA-4 CT60 (rs3087243) polymorphism and autoimmune thyroid diseases susceptibility: a comprehensive meta-analysis

OBJECTIVE

To determine whether the cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) CT60 polymorphism (rs3087243) confers susceptibility to autoimmune thyroid disease (AITDs).

METHODS

A meta-analysis was performed using: (1) allelic contrast, (2) recessive model and (3) dominant model. Electronic search of PubMed, Medline and Chinese National Knowledge Infrastructure (CNKI) was conducted to select studies.

RESULTS

Finally, a total of 20 separate studies were available for the current meta-analysis: Graves' disease (GD): 18 studies including 1 Iranian, 6 Caucasian and 11 Asian populations; Hashimoto's thyroiditis (HT): seven studies including one Iranian, three Caucasian and three Asian populations. A significant association was found between the CTLA-4 CT60 polymorphism (rs3087243) and GD, with regard to comparisons between allele and genotype frequencies (all p < 0.001). After stratification by ethnicity, significant relationships were consistently identified both in Caucasian and Asian populations. Furthermore, the association between this allelic variant and HT risk was also found in overall and Asian populations (OR: 1.26, 95% CI: 1.10-1.44; OR: 1.45, 95% CI: 1.19-1.76, respectively).

CONCLUSION

Taken together, our study suggested that the CT60 polymorphism (rs3087243) in CTLA-4 gene might confer susceptibility to the AITDs (GD/HT).

A low-frequency GLIS3 variant associated with resistance to Japanese type 1 diabetes

The role of low-frequency variants in type 1 diabetes (T1D) susceptibility still remains to be clarified. In the present study, we analyzed low-frequency variants of the T1D candidate genes in Japanese. We first screened for protein-changing variants of 24 T1D candidate genes in 96 T1D patients and 96 control subjects, and then the association with T1D was tested in 706 T1D patients and 863 control subjects recruited from the collaborating institutions in Japan. In total, 56 protein-changing variants were discovered; among them, 34 were low-frequency variants (allele frequency < 5%). The association analysis of the low-frequency variants revealed that only the A908V variant of GLIS3 was strongly associated with resistance to T1D (Haldane's odds ratio = 0.046, p = 8.21 × 10(-4), and pc=2.22 × 10(-2)). GLIS3 is a zinc finger transcription factor that is highly expressed in pancreatic beta cells, and regulates beta cell development and insulin gene expression. GLIS3 mRNA is also moderately expressed in the human thymus. The precise mechanism responsible for the association is unclear at present, but the A908V variant may affect autoimmunity to the GLIS3 protein itself; the 908V containing epitope may induce central or peripheral tolerance more efficiently than that of 908A.

Association of cytotoxic T-lymphocyte associated antigen 4 gene polymorphism with type 1 diabetes mellitus: a meta-analysis

To evaluate the association between costimulatory molecule cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) gene polymorphism and type 1 diabetes mellitus(T1DM), sixty-three published studies before December, 2011 were included. Meta-analysis was performed for each genotype in a random/fixed effect model. The combined odds ratio (OR) with 95% confidence interval (95%CI) was calculated to estimate the strength of the association. Overall, significant correlation was noted between CTLA-4 gene polymorphism (i.e. +49A/G, CT60A/G in a per-allele model) and the risk of T1DM (for +49A/G: OR=1.47, 95%CI=1.36-1.60, P<0.001; for CT60A/G: OR=1.31, 95%CI=1.18-1.45, P<0.001). However, no significant association was noted between C(-318)T polymorphism and T1DM. In the subgroup analysis, for +49A/G and CT60A/G, the statistically significant associations were also demonstrated in diverse racial descents (Caucasian and Asian) and age of onset (<20 years and >20 years). In conclusion, our results suggest that CTLA-4 polymorphism contributes to the susceptibility of T1DM.

Clinical and genetic characteristics of autoimmune polyglandular syndrome type 3 variant in the Japanese population

OBJECTIVE

Type 1 diabetes (T1D) is commonly associated with autoimmune thyroid disease (AITD), and the occurrence of both T1D and AITD in a patient is defined as autoimmune polyglandular syndrome type 3 variant (APS3v). We aimed to clarify the differences in the clinical and genetic characteristics of APS3v patients and T1D patients without AITD [T1D/AITD(-)] in the Japanese population.

DESIGN/PATIENTS

Our subjects were 54 APS3v patients and 143 T1D/AITD(-) patients who were consecutively diagnosed at Nagasaki University Hospital from 1983 to the present.

RESULTS

A remarkable female predominance, a slow and older age onset of T1D, and a higher prevalence of glutamic acid decarboxylase autoantibodies were observed in APS3v patients compared to T1D/AITD(-) patients. The older onset age of T1D in APS3v patients was associated with a higher proportion of slow-onset T1D. Among the two major susceptible human leukocyte antigen (HLA) class II haplotypes in Japanese T1D, DRB1*0405-DQB1*0401, but not DRB1*0901-DQB1*0303, was associated with APS3v patients. Furthermore, DRB1*0803-DQB1*0601 was not protective in patients with APS3v. The frequencies of the GG genotype in +49G>A and +6230G>A polymorphism in the CTLA4 gene were significantly higher in T1D/AITD(-) patients, but not in APS3v patients, compared to control subjects.

CONCLUSIONS

In conclusion, we found notable differences in the clinical and genetic characteristics of APS3v patients and T1D/AITD(-) patients in the Japanese population, and the differences in the clinical characteristics between the two groups may reflect distinct genetic backgrounds including the HLA DRB1-DQB1 haplotypes and CTLA4 gene polymorphisms.

Novel associations for hypothyroidism include known autoimmune risk loci

Hypothyroidism is the most common thyroid disorder, affecting about 5% of the general population. Here we present the current largest genome-wide association study of hypothyroidism, in 3,736 cases and 35,546 controls. Hypothyroidism was assessed via web-based questionnaires. We identify five genome-wide significant associations, three of which are well known to be involved in a large spectrum of autoimmune diseases: rs6679677 near PTPN22, rs3184504 in SH2B3, and rs2517532 in the HLA class I region (-values , , and , respectively). We also report associations with rs4915077 near VAV3 (-value ) and rs925489 near FOXE1 (-value ). VAV3 is involved in immune function, and FOXE1 and PTPN22 have previously been associated with hypothyroidism. Although the HLA class I region and SH2B3 have previously been linked with a number of autoimmune diseases, this is the first report of their association with thyroid disease. The VAV3 association is also novel. We also show suggestive evidence of association for hypothyroidism with a SNP in the HLA class II region (independent of the other HLA association) as well as SNPs in CAPZB, PDE8B, and CTLA4. CAPZB and PDE8B have been linked to TSH levels and CTLA4 to a variety of autoimmune diseases. These results suggest heterogeneity in the genetic etiology of hypothyroidism, implicating genes involved in both autoimmune disorders and thyroid function. Using a genetic risk profile score based on the top association from each of the five genome-wide significant regions in our study, the relative risk between the highest and lowest deciles of genetic risk is 2.0.

Hashimoto's Thyroiditis: From Genes to the Disease

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disorder. Intrathyroidal lymphocytic infiltration is followed by a gradual destruction of the thyroid gland which may lead to subclinical or overt hypothyroidism. Biochemical markers of the disease are thyroid peroxidase and/or thyroglobulin autoantibodies in the serum which are present with a higher prevalence in females than in males and increase with age. Although exact mechanisms of aetiology and pathogenesis of the disorder are not completely understood, a strong genetic susceptibility to the disease has been confirmed predominantly by family and twin studies. Several genes were shown to be associated with the disease occurrence, progression, and severity. Genes for human leukocyte antigen, cytotoxic T lymphocyte antigen-4, protein tyrosine phosphatase nonreceptor-type 22, thyroglobulin, vitamin D receptor, and cytokines are considered to be of utmost importance. Amongst endogenous factors for the disease development, the attention is focused predominantly on female sex, pregnancy with postpartum period and fetal microchimerism. Environmental factors influencing HT development are iodine intake, drugs, infections and different chemicals. Disturbed self-tolerance accompanied by the increased antigen presentation is a prerequisite for the HT occurrence, whereas proper interaction of thyroid cells, antigen presenting cells, and T cells are necessary for the initiation of thyroid autoimmunity. Secreted cytokines lead predominantly to T-helper type 1 (Th1) response as well as to Th 17 response which has only recently been implicated. Final outcome of HT is thyroid destruction which is mostly a consequence of the apoptotic processes combined with T-cell mediated cytotoxicity.

Analysis of the HLA and non-HLA susceptibility loci in Japanese type 1 diabetes

BACKGROUND

We previously reported the associations of human leukocyte antigen (HLA) (DRB1 and DQB1), INS, CTLA4, IL2RA, ERBB3 and CLEC16A with Japanese type 1 diabetes (T1D). In this study, we jointly analysed these loci in addition to IFIH1 and IL7R.

METHODS

A maximum of 790 T1D patients and 953 control subjects were analysed. HLA was determined by sequencing-based typing. Seven non-HLA single nucleotide polymorphisms were genotyped using TaqMan assay.

RESULTS

HLA DRB1*0405, DRB1*0901 and DRB1*0802-DQB1*0302 haplotypes were positively associated with T1D, while the DRB1*15 haplotypes were negatively associated. Non-HLA single nucleotide polymorphisms, INS, IL2RA, ERBB3, CLEC16A and IL7R were associated with T1D. By a prediction model using the HLA loci alone (HLA model) or the non-HLA loci alone (non-HLA model), it was revealed that the cumulative effect of the non-HLA model was much weaker than that of the HLA model (average increase in odds ratio: 1.17 versus 3.14). Furthermore, the area under the receiver operating characteristic curve of the non-HLA model was also much smaller than that of the HLA model (0.65 versus 0.81, p<10(-11)). Finally, a patient-only analysis revealed the susceptible HLA haplotypes and the risk allele of INS to be negatively associated with slower onset of the disease. In addition, the DRB1*0901 haplotype and the risk alleles of ERBB3, CLEC16A and CTLA4 were positively associated with the co-occurrence of thyroid autoimmunity.

CONCLUSIONS

Although several non-HLA susceptibility genes in Japanese were confirmed trans-racially and appear to contribute to the heterogeneity of the clinical phenotypes, the cumulative effect on the ability to predict the development of T1D was weak.

Thyroid disorders and diabetes mellitus

Studies have found that diabetes and thyroid disorders tend to coexist in patients. Both conditions involve a dysfunction of the endocrine system. Thyroid disorders can have a major impact on glucose control, and untreated thyroid disorders affect the management of diabetes in patients. Consequently, a systematic approach to thyroid testing in patients with diabetes is recommended.

Clinical and genetic characteristics of patients with autoimmune thyroid disease with anti-islet autoimmunity

In contrast to the large number of studies on autoimmunity against the thyroid gland in patients with type 1 diabetes mellitus, little is known about the anti-islet autoimmune status in patients with autoimmune thyroid diseases (AITDs). We therefore studied the anti-islet autoimmune status in patients with AITD and the clinical and genetic characteristics of AITD patients with anti-islet autoimmunity. The positivity and titer of glutamic acid decarboxylase antibody (GAD Ab) were studied in 866 Japanese patients with AITD (546 with Graves disease and 320 with Hashimoto thyroiditis), 221 patients with thyroid disease of nonautoimmune origin, and 282 control subjects. The clinical characteristics and genotypes of HLA-DRB1, DQB1, and CTLA4 were compared between AITD patients with and without GAD Ab. The prevalence of GAD Ab was significantly higher in AITD patients than in control subjects (5.8% vs 2.1%, P = .01), particularly in Graves disease (7.1% vs 2.1%, P = .0019). The prevalence of diabetes mellitus was significantly higher in AITD patients with GAD Ab than in those without (40.0% vs 10.1%, P < .0001), particularly in those with a high titer of GAD Ab (high vs low titer: 64% vs 16%, P = .001) and also in those positive for insulinoma-associated antigen 2 (IA-2) Ab (IA-2 positive vs negative: 75.0% vs 31.3%, P = .016). The AITD patients with GAD Ab were characterized by younger age at onset of diabetes, lower body mass index, higher hemoglobin A(1c) level, and higher frequency of insulin therapy than those without GAD Ab. The frequency of the DRB1*0405-DQB1*0401 haplotype was significantly higher in AITD patients with GAD Ab than in those without GAD Ab and control subjects. A single nucleotide polymorphism (rs3087243) of CTLA4 was significantly associated with AITD, but not with positivity of GAD Ab. These results indicate that patients with AITD, and in particular Graves disease, are prone to develop β-cell autoimmunity and insulin-requiring diabetes, particularly those with a high titer of GAD Ab and/or positive for both GAD and IA-2 Ab. Glutamic acid decarboxylase Ab positivity in AITD patients was associated with HLA, conferring susceptibility to type 1 diabetes mellitus.

High titre of antiglutamic acid decarboxylase autoantibody is a strong predictor of the development of thyroid autoimmunity in patients with type 1 diabetes and latent autoimmune diabetes in adults

OBJECTIVE

Type 1 diabetes mellitus (T1DM) is frequently associated with autoimmune thyroid diseases (AITD), but little is known about the risk of AITD in latent autoimmune diabetes in adults (LADA). We evaluated the genetic and immunological factors involved in the development of thyroid autoimmunity in patients with LADA and T1DM.

PATIENTS AND MEASUREMENTS

One hundred and ninety T1DM and 135 LADA patients were recruited in the study. Thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb), glutamic acid decarboxylase antibody (GADA) and thyroid function were measured. The cytotoxic-lymphocyte-associated antigen-4 (CTLA-4) +49A/G and CT60 polymorphisms and the human leucocyte antigen (HLA)-DQA1-DQB1 genotype were determined.

RESULTS

The prevalence of thyroid antibodies (TGAb and/or TPOAb) and thyroid dysfunction was 27·4% and 9·5% in patients with T1DM, and 21·5% and 11·1% in patients with LADA. Thyroid-antibody-positive T1DM patients had higher frequencies of GADA and HLA-DQA1*03-DQB1*0401 haplotypes than thyroid-antibody negatives (P < 0·05). Thyroid-antibody-positive LADA patients had higher GADA titre, lower C-peptide levels and higher frequencies of HLA-DQA1*03-DQB1*0401 haplotypes (P < 0·05). The CTLA-4 +49A/G and CT60 polymorphism was associated with T1DM complicated with thyroid autoimmunity (OR = 2·33 and 2·54). Logistic regression revealed that only high-titre GADA was associated with development of thyroid autoimmunity in patients with T1DM and LADA (OR = 3·50 and 3·10, respectively), and the presence of thyroid antibody predicted high risk for thyroid dysfunction in patients with T1DM and LADA (OR = 9·25 and 10·70, respectively).

CONCLUSION

Regular screening of thyroid antibody and function are recommended, especially in patients with T1DM and LADA with high GADA titre.

Evaluation of six CTLA-4 polymorphisms in high-risk melanoma patients receiving adjuvant interferon therapy in the He13A/98 multicenter trial

Purpose

Interferon is approved for adjuvant treatment of patients with stage IIb/III melanoma. The toxicity and uncertainty regarding survival benefits of interferon have qualified its acceptance, despite significant durable relapse prevention in a fraction of patients. Predictive biomarkers that would enable selection of patients for therapy would have a large impact upon clinical practice. Specific CTLA-4 polymorphisms have previously shown an association with response to CTLA-4 blockade in patients with metastatic melanoma and the development of autoimmunity.

Experimental design

286 melanoma patients and 288 healthy controls were genotyped for six CTLA-4 polymorphisms previously suggested to be important (AG 49, CT 318, CT 60, JO 27, JO30 and JO 31). Specific allele frequencies were compared between the healthy and patient populations, as well as presence or absence of these in relation to recurrence. Alleles related to autoimmune disease were also investigated.

Results

No significant differences were found between the distributions of CTLA-4 polymorphisms in the melanoma population compared with healthy controls. Relapse free survival (RFS) and overall survival (OS) did not differ significantly between patients with the alleles represented by these polymorphisms. No correlation between autoimmunity and specific alleles was shown. The six polymorphisms evaluated where strongly associated (Fisher's exact p-values < 0.001 for all associations) and significant linkage disequilibrium among these was indicated.

Conclusion

No polymorphisms of CTLA-4 defined by the SNPs studied were correlated with improved RFS, OS, or autoimmunity in this high-risk group of melanoma patients.

Association of single nucleotide polymorphisms in cytotoxic T-lymphocyte antigen 4 and susceptibility to autoimmune type 1 diabetes in Tunisians

In addition to HLA and insulin genes, the costimulatory molecule CTLA-4 gene is a confirmed type 1 diabetes (T1D) susceptibility gene. Previous studies investigated the association of CTLA-4 genetic variants with the risk of T1D, but with inconclusive findings. Here, we tested the contributions of common CTLA-4 gene variants to T1D susceptibility in Tunisian patients and control subjects. The study subjects comprised 228 T1D patients (47.8% females) and 193 unrelated healthy controls (45.6% females). Genotyping for CTLA-4 CT60A/G (rs3087243), +49A/G (rs231775), and -318C/T (rs5742909) was performed by PCR-restriction fragment length polymorphism (RFLP) analysis. The minor-allele frequencies (MAF) for the three CTLA-4 variants were significantly higher in T1D patients, and significantly higher frequencies of homozygous +49G/G and homozygous CT60G/G genotypes were seen in patients, which was confirmed by univariate regression analysis (taking the homozygous wild type as a reference). Of the eight possible three-locus CTLA-4 haplotypes (+49A/G, -318C/T, and CT60A/G) identified, multivariate regression analysis confirmed the positive association of ACG (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.26 to 2.94), GCG (OR, 2.40; 95% CI, 1.11 to 5.21), and GTA (OR, 4.67; 95% CI, 1.52 to 14.39) haplotypes with T1D, after confounding variables were adjusted for. Our results indicate that CTLA-4 gene variants are associated with increased T1D susceptibility in Tunisian patients, further supporting a central role for altered T-cell costimulation in T1D pathogenesis.

Genetics of the autoimmune polyglandular syndrome type 3 variant

BACKGROUND

Autoimmune thyroid diseases (AITD) and type 1 diabetes (T1D) are the most common autoimmune endocrine disorders. They occur frequently together in the same individual. This disease combination is denominated as autoimmune polyglandular syndrome type 3 variant (APS3v). This review aims to describe the genetic and pathological background of the syndrome. The joint susceptibility genes for AITD and T1D as well as the underlying pathogenetic mechanisms contributing to the development of autoimmunity are summarized.

SUMMARY

Family and population studies showed that the APS3v syndrome has a strong genetic background. Whole genome and candidate gene approaches identified several gene variations that are present in both AITD and T1D. Most important common disease susceptibility genes are human leucocyte antigen (chromosome 6), cytotoxic T-lymphocyte-associated antigen 4 (chromosome 2), protein tyrosine phosphatase nonreceptor type 22 (chromosome 1), forkhead box P3 (X chromosome), and the interleukin-2 receptor alpha/CD25 gene region (chromosome 10), all of which contributing to the susceptibility to APS3v. With respect to the underlying pathogenetic mechanisms, these genes are altogether involved in the immune regulation, in particular in the immunological synapse and T-cell activation. In addition to these common genes, there are further candidate genes with joint risk for AITD and T1D, in particular the v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 gene (chromosome 12) and C-type lectin domain family 16 member A gene (chromosome 16). The latter one might be involved in pathogen recognition.

CONCLUSIONS

AITD and T1D share common susceptibility gene variants that possibly act pleiotropically as risk factors for the development of autoimmunity in APS3v. The functional consequences of the genetic variants as well as their interactions should be explored in greater detail. In particular, the functional consequences of the variants of forkhead box P3 predisposing to APS3v need to be elucidated. Finally, further large-scale genome-wide associations studies of single-nucleotide polymorphism variations capturing many thousand individual genetic profiles are warranted to identify further genes that are linked to the etiology of APS3v.

Autoimmune polyendocrine syndromes: clues to type 1 diabetes pathogenesis

Autoimmune diseases such as type 1 diabetes are complex in their pathogenesis. One approach to improving our understanding of type 1 diabetes is the study of diseases that represent more extreme examples of autoimmunity. Autoimmune polyendocrine syndromes (APS) are relatively rare diseases that often include type 1 diabetes as part of the disease phenotype. Recently, there has been tremendous progress in unraveling some of the underlying mechanisms of APS. Here, we highlight the APS disorders with the perspective of the clues they can offer to the pathogenesis and treatment of type 1 diabetes.

Association of CT60 cytotoxic T lymphocyte antigen-4 gene polymorphism with thyroid autoantibody production in patients with Hashimoto's and postpartum thyroiditis

Strong genetic contribution has been demonstrated to influence the development of autoimmune thyroid disease (AITD) as well as thyroid autoantibody production. In order to assess the relation between CT60 cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphism and thyroid autoantibody production, we investigated 180 consecutive newly diagnosed patients with two forms of AITD, 105 with Hashimoto's thyroiditis (HT) and 75 with postpartum thyroiditis (PPT). We evaluated thyroid function, measured antibodies against thyroid peroxidase (TPO) and thyroglobulin (Tg), and determined CT60 CTLA-4 gene polymorphism. In HT, TPO antibody median value was significantly lower in the AA compared to the AG and GG genotypes (65, 122 and 319 U/ml, P<0.005), while the Tg antibody median value was lower in the AA compared to the AG genotype (91 and 189 U/ml, P<0.02). In PPT, the frequency of thyroid autoantibody-positive patients was higher among G-allele-carrying genotypes (P<0.04). Similar to HT, the TPO antibody median value was lower in the AA compared to the AG and GG genotypes (12, 130 and 423 U/ml, P<0.006). Hypothyroid PPT patients were more often thyroid autoantibody-positive (P<0.005) and the TPO antibody median value was higher compared to hyperthyroid PPT patients (500 and 32 U/ml, P<0.0001). The frequency of the G-allele was significantly higher among hypothyroid patients (P<0.05). Our data suggest that in both HT and PPT, the CT60 CTLA-4 gene polymorphism contributes importantly to thyroid autoantibody production. In PPT, the genotype also seems to influence thyroid function, as patients with the polymorphous allele are more prone to develop hypothyroid form of PPT.

Approaches in type 1 diabetes research: A status report

Type 1 diabetes is a multifactorial disease with an early age of onset, in which the insulin producing beta cell of the pancreas are destroyed because of autoimmunity. It is the second most common chronic disease in children and account for 5% to 10% of all diagnosed cases of diabetes. India is having an incidence of 10.6 cases/year/100,000, and recent studies indicate that the prevalence of type 1 diabetes in India is increasing. However in view of poor health care network, there is no monitoring system in the country. Of the 18 genomic intervals implicated for the risk to develop type 1 diabetes, the major histocompatibility complex (MHC) region on chromosome 6p21.31 has been the major contributor estimated to account for 40-50%, followed by 10% frequency of INS-VNTR at 5' flanking region of the insulin gene on chromosome 11p15.5. However, population studies suggest that > 95% of type 1 diabetes have HLA-DR3 or DR4, or both, and in family studies, sibling pairs affected with type 1 diabetes have a non-random distribution of shared HLA haplotypes. As predisposing genetic factors such as HLA alleles are known, immunological interventions to prevent type 1 diabetes are of great interest. In the present study we have reviewed the status of molecular genetics of the disease and the approaches that need to be adopted in terms of developing patient and suitable control cohorts in the country.

Prediction of candidate primary immunodeficiency disease genes using a support vector machine learning approach

Screening and early identification of primary immunodeficiency disease (PID) genes is a major challenge for physicians. Many resources have catalogued molecular alterations in known PID genes along with their associated clinical and immunological phenotypes. However, these resources do not assist in identifying candidate PID genes. We have recently developed a platform designated Resource of Asian PDIs, which hosts information pertaining to molecular alterations, protein-protein interaction networks, mouse studies and microarray gene expression profiling of all known PID genes. Using this resource as a discovery tool, we describe the development of an algorithm for prediction of candidate PID genes. Using a support vector machine learning approach, we have predicted 1442 candidate PID genes using 69 binary features of 148 known PID genes and 3162 non-PID genes as a training data set. The power of this approach is illustrated by the fact that six of the predicted genes have recently been experimentally confirmed to be PID genes. The remaining genes in this predicted data set represent attractive candidates for testing in patients where the etiology cannot be ascribed to any of the known PID genes.

The human leukocyte antigen class II gene has different contributions to autoimmune type 1 diabetes with or without autoimmune thyroid disease in the Japanese population

AIM

Type 1 diabetes (T1D) is associated with autoimmune thyroid disease (AITD). The human leukocyte antigen (HLA) has been extensively studied in these diseases. We aimed to clarify the contribution of AITD on the susceptibility and resistance of the HLA subtype to autoimmune T1D in the Japanese population.

METHODS

The frequency of the HLA DR-DQ haplotype was compared between 56 autoimmune T1D patients with AITD and 71 autoimmune T1D patients without AITD, and control subjects.

RESULTS

The frequencies of DRB1 0405-DQB1 0401, DRB1 0802-DQB1 0302, and DRB1 0901-DQB1 0303 haplotypes were significantly higher in T1D patients with AITD than in control subjects. The frequencies of DRB1 0101-DQB1 0501, DRB1 0901-DQB1 0303, and DRB1 1302-DQB1 0604 haplotypes were significantly higher in T1D patients without AITD than in control subjects. The frequencies of DRB1 1101-DQB1 0301 and DRB1 1501-DQB1 0602 haplotypes were significantly lower in T1D patients with or without AITD than in control subjects.

CONCLUSIONS

Our results suggest that the susceptibility of the HLA subtype to autoimmune T1D differs between T1D with AITD and T1D without AITD, whereas there is no difference between the two groups with regard to HLA subtypes that confer protection against autoimmune T1D.

Association of polymorphism at position 49 in exon 1 of the cytotoxic T-lymphocyte-associated factor 4 gene with Graves' disease refractory to medical treatment, but not with amiodarone-associated thyroid dysfunction

BACKGROUND

Recently, the G allele of the cytotoxic T-lymphocyte-associated factor 4 (CTLA-4) exon 1 single-nucleotide polymorphism (CTLA-4 A/G(49)) has been identified as the most informative marker in patients with Graves' disease. Patients with the G/G genotype are refractory to medical treatment and frequently relapse after discontinuation of antithyroid drugs. Therefore, we analyzed CTLA-4 A/G(49) in patients who had been treated with (131)I. Further, a preliminary report has suggested that amiodarone-associated thyroid dysfunction (AATD) has a relationship with human leukocyte antigen (HLA) class I and class II.

METHOD

CTLA-4 genotypes in exon 1 (A/G(49)) and CT60 were analyzed in 415 Japanese patients with Graves' disease and 65 patients with AATD.

RESULTS

The frequencies of the G alleles and G/G genotype at the both polymorphisms were significantly higher in Graves' patients compared with normal subjects. Compared with CT60, the frequencies of the G alleles and G/G genotypes at the A/G(49) were more significantly higher in patients with persistently positive thyrotropin receptor antibody despite >5 years of antithyroid drug therapy, compared with those whose thyrotropin receptor antibody became negative in <5 years (p < 0.0001). Consequently, the frequencies of the G/G genotype and G allele at the A/G(49) were also significantly higher in patients with Graves' disease who received (131)I therapy (p < 0.05). However, there was no significant difference in the A/G polymorphisms in the 65 patients with AATD.

CONCLUSIONS

The G/G genotype in exon 1 (A/G(49)) is frequently expressed in Graves' disease patients who are refractory to antithyroid drug treatment. Therefore, the G/G genotype in A/G(49) would be a useful predictor of Graves' patients who are suitable for radioiodine therapy. Although the number of analyzed patients was small, our preliminary data suggest that the CTLA-4 gene polymorphisms might be unassociated with AATD.

Association studies of the SAS-ZFAT, IL-23R, IFIH1 and FOXP3 genes in autoimmune thyroid disease

Autoimmune thyroid diseases (AITDs) are complex diseases caused by an interaction between susceptibility genes and environmental triggers. Genetic susceptibility in combination with external factors, such as dietary iodine, is believed to initiate the autoimmune response against thyroid antigens. Abundant epidemiological data, including family and twin studies, point to a strong genetic influence in the development of AITDs. Various techniques have been employed to identify genes contributing to the etiology of AITDs, including candidate gene analysis and whole-genome screening. These studies have enabled the identification of several loci (genetic regions) that are linked to AITDs and, in some of these loci, putative AITD-susceptibility genes have been identified. Some of these genes/loci are unique to Graves' disease (GD) and Hashimoto's thyroiditis (HT), and some are common to both diseases, indicating that there is a shared genetic susceptibility to GD and HT. The putative GD and HT susceptibility genes include both immune-modifying genes (e.g., HLA, CTLA-4 and PTPN22) and thyroid-specific genes (e.g., TSHR and Tg). In this special report, we focus on the newest genes identified and not on those previously identified, such as HLA and CTLA-4, for which there are many reviews.

A common CTLA4 polymorphism confers susceptibility to autoimmune thyroid disease in celiac children

BACKGROUND

Cytotoxic T-lymphocyte-associated protein 4 (CTLA4) is a strong candidate gene in autoimmunity susceptibility. In particular, the CTLA4 CT60 A/G dimorphism has been associated with celiac disease (CD) and was reported to be strongly associated with autoimmune thyroid disease (AITD).

AIMS

This study aimed to investigate the possible influences of the CTLA4 CT60 A/G polymorphism in the susceptibility of Italian children to CD and in the predisposition to develop AITD in children with CD.

PATIENTS AND METHODS

We genotyped 317 Italian celiac children, including 44 patients (13.9%) who developed AITD after CD diagnosis and 350 controls.

RESULTS

The CTLA4 CT60 GG genotype distribution did not show any significant difference between children with CD and control population (p=0.4). On the contrary, the frequency of the GG genotype was significantly higher in patients with CD complicated with AITD than in control subjects (p=0.002) and CD patients without AITD (p=0.02).

CONCLUSION

Our data show a significant effect of the CTLA4 CT60G allele at the homozygous state on the risk of developing AITD in children with CD and suggest that the reported association of the CTLA4 CT60 A/G polymorphism with CD is limited to the subgroup of patients who are or will be complicated with AITD.

Autoimmune thyroiditis and diabetes: dissecting the joint genetic susceptibility in a large cohort of multiplex families

CONTEXT

Epidemiological data support a shared genetic susceptibility to autoimmune thyroid disease (AITD) and type 1 diabetes (T1D). Both diseases frequently occur within the same family and in the same individual. Patients developing both T1D and AITD are considered to have an autoimmune polyglandular syndrome type 3 variant (APS3v).

OBJECTIVE

The goals of this study were to identify the joint susceptibility loci/genes for T1D and AITD.

SETTINGS

The study was conducted at an academic medical center.

PARTICIPANTS AND MAIN OUTCOME MEASURES

We used whole genome and candidate gene approaches in a data set of 88 families multiplex for T1D and AITD (448 individuals).

RESULTS

We identified three loci, on chromosomes 2p, 6p, and Xp, showing linkage when individuals with either T1D or AITD were classified as affected. The 6p locus contained the human leukocyte antigen class II genes, and the Xp locus contained the FOXP3 gene. Three loci, on 2q, 6p (human leukocyte antigen class II), and Xp, showed evidence for linkage when only APS3v individuals (T1D+AITD) were classified as affected. Analysis of positional candidate genes strongly supported CTLA-4 as the gene on 2q associated with APS3v and FOXP3 as the gene on Xp associated with T1D or AITD and APS3v. In addition, the PTPN22 and insulin variable number tandem repeat genes showed significant associations with T1D or AITD in our families.

CONCLUSIONS

Our results demonstrate a strong shared genetic susceptibility to T1D and AITD, with most shared genes involved in immune regulation, suggesting that immune dysregulation plays an important role in the joint susceptibility to T1D and AITD.

Genetic determinants of Type 1 diabetes: immune response genes

Type 1 diabetes (T1D) is a polygenic autoimmune disease. Susceptibility to T1D is strongly linked to a major genetic locus that is the MHC, and several other minor loci including insulin, cytotoxic T-lymphocyte-associated antigen-4, PTPN22 and others that contribute to diabetes risk in an epistatic way. We have observed that there are three sets of DR3-positive autoimmunity-favoring haplotypes in the north-Indian population, including B50-DR3, B58-DR3 and B8-DR3. The classical Caucasian autoimmunity favoring AH8.1 (HLA-A1-B8-DR3) is rare in the Indian population, and has been replaced by a variant AH8.1v, which differs from the Caucasian AH8.1 at several gene loci. Similarly, there are additional HLA-DR3 haplotypes, A26-B8-DR3 (AH8.2), A24-B8-DR3 (AH8.3), A3-B8-DR3 (AH8.4) and A31-B8-DR3 (AH8.5), of which AH8.2 is the most common. The fact that disease-associated DR3-positive haplotypes show heterogeneity in different populations suggests that these might possess certain shared components that are involved in the development of autoimmunity.

[Genetic and humoral autoimmunity markers of type 1 diabetes: from theory to practice]

Type 1 A diabetes mellitus (T1AD) results from the autoimmune destruction of the insulin producing pancreatic beta-cells. The largest contribution to genetic susceptibility comes from several genes located in the major histocompatibility complex on chromosome 6p21.3 (IDDM1 locus), accounting for at least 40% of the family aggregation of this disease. The highest-risk human leukocyte antigen HLA genotype for T1AD is DR3-DQA1*0501-DQB1*0201/DR4-DQA1*0301-DQB1*0302, whereas -DR15-DQA1*0102-DQB1*0602 haplotype is associated with dominant protection. Three other T1D loci associated with predisposition are the Variable Number for Tandem Repeats (VNTR) near the insulin gene (IDDM2), which accounts to 10% of genetic susceptibility, the Cytotoxic T-Lymphocyte-associated Antigen (CTLA-4)(IDDM 12) and the Protein Tyrosine Phosphatasis Nonreceptor-type 22 (PTPN22). Many other gene suspected to predispose to autoimmunity have been investigated. T1AD is frequently associated with autoimmune thyroid disease, celiac disase, Addison s disease and many other autoimmune diseases, characterized by organ-specific autoantibodies and related to the same genetic background. Using these autoantibodies, organ specific autoimmunity may be detected before the development of clinical disease preventing significant morbidity.

Genetic association between the interleukin-2 receptor-alpha gene and mode of onset of type 1 diabetes in the Japanese population

CONTEXT/OBJECTIVE

The IL-2 receptor-alpha (IL2RA), also known as CD25, is expressed on the regulatory T cells, which play an important role in the control of immune responses and the maintenance of immune homeostasis. Our objective was to determine whether variants in the IL2RA gene are associated with type 1 diabetes in the Japanese population.

DESIGN/PATIENTS

We genotyped the four single-nucleotide polymorphisms (rs706778, rs3118470, ss52580101, and rs11594656) of the IL2RA in 885 patients with type 1 diabetes and 606 control subjects of Japanese origin. The allele and genotype frequencies were examined in the patient groups stratified by their mode of onset in a case-control study.

RESULTS

We found evidence of association with acute-onset, but not slow-onset and fulminant, type 1 diabetes for two of the four single-nucleotide polymorphisms genotyped (rs706778 and rs3118470). The rs706778 A allele and the rs3118470 G allele were associated with an increased disease risk [odds ratio (OR) for rs706778 AA genotype 1.54, P = 4.2 x 10(-4) and OR for rs3118470 GG genotype 1.50, P = 0.0019, respectively]. Furthermore, the A-G haplotype was associated with increased type 1 diabetes risk in the acute-onset form (OR 1.30, P = 0.002).

CONCLUSIONS

The present data confirm the type 1 diabetes association with IL2RA and provide evidence that the different contributions of the IL2RA in the susceptibility to acute-onset and other forms of type 1 diabetes in the Japanese population.

Simultaneous triple organ specific autoantibody profiling in adult patients with type 1 diabetes mellitus and their first-degree relatives

AIMS

We aimed to document prevalence and clinical presentations of seropositivities for glutamate decarboxylase (GAD)-antibody, celiac's disease (CD) and autoimmune thyroiditis (AIT) in adult patients with type 1 diabetes mellitus (T1DM), and their first-degree relatives.

METHODS

Sixty-five patients with T1DM, 124 first-degree relatives and 65 healthy controls were screened for GAD-antibody, anti-thyroid peroxidase (ATPO), anti-thyroid stimulating hormone receptor (TSHR), anti-tissue transglutaminase and anti-gliadin antibodies in a matched case-control study.

RESULTS

Prevalence of more than one seropositivity for CD-associated antibodies in T1DM-group is 6.0 times increased, compared with controls (p < 0.05). ATPO seropositivity is 5.3 times increased in T1DM group (p < 0.05), but TSHR antibody is comparable with controls (p > 0.05). Seropositivities for T1DM, AIT and CD are 4.3, 1.9 and 2.4 times more prevalent among first-degree relatives respectively, compared with controls (p < 0.05). Pathologically confirmed cases with CD among first-degree relatives were all identified at screening. In contrast, all of pathologically confirmed cases with CD in T1DM group, were either previously diagnosed or symptomatic at time of screening. In the group of patients with T1DM, 31% of seropositive cases for anti-ATPO were clinically latent for AIT, and 74% of ATPO (+) cases were identified at current screening study. Sixty-four per cent of ATPO (+) first-degree relatives were clinically latent for AIT, and 54% were identified at screening.

CONCLUSION

Type 1 diabetes mellitus, CD and AIT represent a significant overlap in an adult population with already-diagnosed T1DM and their first-degree relatives. With regard to clinical presentations, CD was less likely to be clinically silent than AIT among patients with T1DM.

The protein tyrosine phosphatase non-receptor type 22 C1858T polymorphism is a joint susceptibility locus for immunthyroiditis and autoimmune diabetes

BACKGROUND

The lymphoid tyrosine phosphatase (LYP) encoded by the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene is a strong inhibitor of T cells. The single nucleotide polymorphism (SNP) C1858T within the PTPN22 gene was recently associated with autoimmune thyroid disease (AITD) and type I diabetes (T1D). The purpose of this study was to examine the joint association of this polymorphism with the co-occurrence of AITD and T1D.

METHODS

In this association study, 310 white subjects were genotyped for the C1858T polymorphism. The study population included 70 patients with both AITD and T1D (AITD+T1D), 70 patients with AITD only, 70 patients with T1D only, and 100 healthy controls. Patients with both AITD and T1D, and controls were also typed for HLA-DRB1. PTPN22 C1858T genotyping was performed by minisequencing. For HLA-DRB1 typing, polymerase chain reaction (PCR) sequence-specific oligonucleotide probes were used.

RESULTS

The PTPN22 1858 minor T-allele frequency was strongly increased in patients with AITD+T1D (23.6%) compared with controls (8.0%, pc<0.001), with patients with AITD only (8.6%, pc=0.006), or with T1D only (10.7%, pc=0.028). T-allele carriers were also more frequently present in the group with AITD+T1D versus controls (41.4% vs. 14.0%, OR=4.35, 95% CI=2.08-9.09), AITD (17.1%, OR=3.42, 95% CI=1.56-7.48), and T1D (21.4%, OR=2.59, 95% CI=1.23-5.45). Especially in subjects with Hashimoto's thyroiditis (HT)+T1D, T-allele carriers were mostly frequent (50% vs. 14%, OR=6.14, 95% CI=2.62-14.38, pc<0.001). Considering all included patients with AITD, T-allele carriers were 29.3% vs. 14.0% in controls (p=0.008, OR=2.54, 95% CI=1.30-4.98). Patients carrying the PTPN22 1858 T allele had a twofold increased frequency of the HLA-DRB1*03 allele (64.7% vs. 37.3%, pc=0.034).

CONCLUSION

The PTPN22 gene is a joint susceptibility locus for AITD (especially HT) and T1D.