Genetics of the autoimmune polyglandular syndrome type 3 variant

Analysis of the AIRE Gene Promoter in Patients Affected by Autoimmune Polyendocrine Syndromes

Autoimmune polyglandular syndromes (APS) are classified into four main categories, APS1-APS4. APS1 is caused by AIRE gene loss of function mutations, while the genetic background of the other APS remains to be clarified. Here, we investigated the potential association between AIRE gene promoter Single Nucleotide Polymorphisms (SNPs) and susceptibility to APS. We sequenced the AIRE gene promoter of 74 APS patients, also analyzing their clinical and autoantibody profile, and we further conducted molecular modeling studies on the identified SNPs. Overall, we found 6 SNPs (-230Y, -655R, -261M, -380S, -191M, -402S) of the AIRE promoter in patients' DNA. Interestingly, folding free energy calculations highlighted that all identified SNPs, except for -261M, modify the stability of the nucleic acid structure. A rather similar percentage of APS3 and APS4 patients had polymorphisms in the AIRE promoter. Conversely, there was no association between APS2 and AIRE promoter polymorphisms. Further AIRE promoter SNPs were found in 4 out of 5 patients with APS1 clinical diagnosis that did not harbor AIRE loss of function mutations. We hypothesize that AIRE promoter polymorphisms could contribute to APS predisposition, although this should be validated through genetic screening in larger patient cohorts and in vitro and in vivo functional studies.

Recurrence risk of autoimmune thyroid and endocrine diseases

BACKGROUND AND OBJECTIVE

The recurrence risk ratio (λ) expresses the risk ratio of index patients' first-degree relatives developing a disease as compared to the general population and is a quantitative measure of the genetic contribution to the disease. This paper offers the results of a specialized center as well as a review of the pertinent literature.

METHODS

Data from 3315 consecutive subjects followed at an ORPHAN academic tertiary referral expert center for endocrine autoimmunity as well as 419 unrelated German families were collected. λ was assessed based on 806 well-documented subjects, 299 index patients with autoimmune glandular (AIGD) and non-endocrine diseases and 507 of their first-degree relatives (328 children, 179 siblings).

RESULTS

As many as 36% of relatives of patients with autoimmune diseases (AID) were affected by various autoimmune conditions. Twenty-five percent and 23% of all relatives had an AIGD or an autoimmune thyroid disease (AITD), respectively. Furthermore, 29% and 25% of relatives of index cases with polyglandular (PGA) and monoglandular (MGA) autoimmunity were affected. The recurrence risk for AITD was increased 16-fold in both children and siblings compared to the general population (λ, 95% CI 16, 11-21 and 16, 12-19, respectively). Furthermore, λ for AITD/AIGD was 21.62 (95% CI 14.17-30.69)/17.57 (11.80-24.36) and 13.48 (8.42-20.52)/10.68 (6.76-16.02) for siblings of patients with PGA and MGA, respectively. Overall, a strong genetic component for AITD and AIGD with a significant genetic impact on the development of PGA was demonstrated.

CONCLUSION

These novel results strongly recommend the screening for AITD and AIGD in children and siblings of index patients with AITD.

Autoimmune Polyglandular Syndrome with Refractory Gait Disturbance

Autoimmune polyglandular syndrome (APS) causes autoimmune diseases of multiple organs and can also present with neurological symptoms. We here report a 58-year-old man who presented with progressive gait disturbance that had started 7 years ago. He had spasticity, reduced deep sensations, and truncal cerebellar ataxia. Laboratory examinations revealed autoantibody-related cobalamin deficiency and the presence of anti-thyroid antibodies and anti-glutamic acid decarboxylase antibodies. His gait worsened after cobalamin replenishment, but additional steroid therapy was effective. APS can cause refractory gait disturbance that requires not only cobalamin replenishment but also immunotherapy.

Shared etiology of type 1 diabetes and Hashimoto's thyroiditis: a population-based twin study

OBJECTIVE

Type 1 diabetes and Hashimoto's thyroiditis frequently cluster in individuals and in families, indicating shared origins. The objective of this study was to investigate familial co-aggregation of these diseases and to quantify shared genetic and environmental factors.

DESIGN

This study is a twin cohort study.

METHODS

National health registers were used to identify cases among 110 814 Swedish twins. Co-aggregation was calculated as risk ratios for type 1 diabetes among co-twins of individuals with Hashimoto's thyroiditis, and vice-versa. Variance explained by genetics (i.e. heritability), and the proportions thereof shared between the diseases, was estimated by contrasting associations in monozygotic and dizygotic twins using structural equation models.

RESULTS

Individuals with one disease were at a high risk for the other disease (adjusted risk ratio: 11.4 (95% CI: 8.5-15.3)). Co-aggregation was more common in monozygotic than in dizygotic pairs, with adjusted risk ratios of 7.0 (95% CI: 3.2-15.1) and 1.7 (95% CI: 0.7-4.1), respectively. Genetic effects shared across diseases accounted for 11% of the variance for type 1 diabetes and 9% of the variance for Hashimoto's thyroiditis, while environmental factors unique to individual twins, but shared across diseases, accounted for 10% of the variance for type 1 diabetes and 18% of the variance for Hashimoto's thyroiditis.

CONCLUSIONS

Both genes and environment unique to individual twins contribute to considerable etiologic overlap between type 1 diabetes and Hashimoto's thyroiditis. These findings add to the current knowledge on the mechanisms behind autoimmune disease clustering and could guide future research aimed at identifying pathophysiological mechanisms and intervention targets.

Improvement of Lipoplexes With a Sialic Acid Mimetic to Target the C1858T PTPN22 Variant for Immunotherapy in Endocrine Autoimmunity

The C1858T variant of the protein tyrosine phosphatase N22 (PTPN22) gene is associated with pathophysiological phenotypes in several autoimmune conditions, namely, Type 1 diabetes and autoimmune thyroiditis. The R620W variant protein, encoded by C1858T, leads to a gain of function mutation with paradoxical reduced T cell activation. We previously exploited a novel personalized immunotherapeutic approach based on siRNA delivered by liposomes (lipoplexes, LiposiRNA) that selectively inhibit variant allele expression. In this manuscript, we functionalize lipoplexes carrying siRNA for variant C1858T with a high affinity ligand of Siglec-10 (Sig10L) coupled to lipids resulting in lipoplexes (LiposiRNA-Sig10L) that enhance delivery to Siglec-10 expressing immunocytes. LiposiRNA-Sig10L lipoplexes more efficiently downregulated variant C1858T PTPN22 mRNA in PBMC of heterozygous patients than LiposiRNA without Sig10L. Following TCR engagement, LiposiRNA-Sig10L more significantly restored IL-2 secretion, known to be paradoxically reduced than in wild type patients, than unfunctionalized LiposiRNA in PBMC of heterozygous T1D patients.

Identification of Differentially Expressed Genes in COVID-19 and Integrated Bioinformatics Analysis of Signaling Pathways

Coronavirus disease 2019 (COVID-19) is acutely infectious pneumonia. Currently, the specific causes and treatment targets of COVID-19 are still unclear. Herein, comprehensive bioinformatics methods were employed to analyze the hub genes in COVID-19 and tried to reveal its potential mechanisms. First of all, 34 groups of COVID-19 lung tissues and 17 other diseases' lung tissues were selected from the GSE151764 gene expression profile for research. According to the analysis of the DEGs (differentially expressed genes) in the samples using the limma software package, 84 upregulated DEGs and 46 downregulated DEGs were obtained. Later, by the Database for Annotation, Visualization, and Integrated Discovery (DAVID), they were enriched in the Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. It was found that the upregulated DEGs were enriched in the type I interferon signaling pathway, AGE-RAGE signaling pathway in diabetic complications, coronavirus disease, etc. Downregulated DEGs were in cellular response to cytokine stimulus, IL-17 signaling pathway, FoxO signaling pathway, etc. Then, based on GSEA, the enrichment of the gene set in the sample was analyzed in the GO terms, and the gene set was enriched in the positive regulation of myeloid leukocyte cytokine production involved in immune response, programmed necrotic cell death, translesion synthesis, necroptotic process, and condensed nuclear chromosome. Finally, with the help of STRING tools, the PPI (protein-protein interaction) network diagrams of DEGs were constructed. With degree ≥13 as the cutoff degree, 3 upregulated hub genes (ISG15, FN1, and HLA-G) and 4 downregulated hub genes (FOXP3, CXCR4, MMP9, and CD69) were screened out for high degree. All these findings will help us to understand the potential molecular mechanisms of COVID-19, which is also of great significance for its diagnosis and prevention.

Cepharanthine Blocks Presentation of Thyroid and Islet Peptides in a Novel Humanized Autoimmune Diabetes and Thyroiditis Mouse Model

Autoimmune polyglandular syndrome type 3 variant (APS3v) refers to an autoimmune condition in which both type 1 diabetes (T1D) and autoimmune thyroiditis (AITD) develop in the same individual. HLA-DR3 confers the strongest susceptibility to APS3v. Previously we reported a unique amino acid signature pocket that predisposes to APS3v. We found that this pocket is flexible and can trigger APS3v by presenting both thyroid (Tg.1571, TPO.758) and islet (GAD.492) peptides to induce autoimmune response. We hypothesized that blocking the specific APS3v-HLA-DR3 pocket from presenting thyroid/islet antigens can block the autoimmune response in APS3v. To test this hypothesis we performed a virtual screen of small molecules blocking APS3v-HLA-DR3, and identified 11 small molecules hits that were predicted to block APS3v-HLA-DR3. Using the baculovirus-produced recombinant APS3v-HLA-DR3 protein we tested the 11 small molecules in an in vitro binding assay. We validated 4 small molecule hits, S9, S5, S53 and S15, that could block the APS3v-HLA-DR3 pocket in vitro. We then developed a novel humanized APS3v mouse model induced by co-immunizing a peptide mix of Tg.1571, TPO.758 and GAD.492. The immunized mice developed strong T-cell and antibody responses to the thyroid/islet peptides, as well as mouse thyroglobulin. In addition, the mice showed significantly lower free T4 levels compared to controls. Using the APS3v mouse model, we showed that one of the 4 small molecules, Cepharanthine (S53), blocked T-cell activation by thyroid/islet peptides ex vivo and in vivo. These findings suggested Cepharanthine may have a therapeutic potential in APS3v patients carrying the specific APS3v-HLA-DR3 pocket.

Search for Genetic Predictors of Adult Autoimmune Polyendocrine Syndrome in Monozygotic Twins

Autoimmune polyendocrine syndromes (APS) are a heterogeneous group of diseases characterized by the presence of autoimmune dysfunction of 2 or more endocrine glands and other non-endocrine organs. The components of the syndrome can manifest throughout life: in childhood—APS type 1 (the juvenile type) and in adulthood—APS type 2, 3, and 4 (the adult types). Adult types of APS are more common in clinical practice. It is a polygenic disease associated with abnormalities in genes encoding key regulatory proteins of the major histocompatibility complex (MHC). The search of for candidate genes responsible for mutations in adult APS is continuing. Genetic predisposition is insufficient for the manifestation of the APS of adults, since the penetrance of the disease, even among monozygotic twins, does not approach 100% (30–70%). The article presents the case of isolated Addison’s disease and APS type 2 in monozygotic twins with a revealed compound heterozygosity in the candidate gene VTCN1.

Autoinmune polyendocrinopathy

Pluriglandular autoimmune syndrome (APS) can affect multiple endocrine glands and is associated with other autoimmune diseases. APS type 1 presents with hypoparathyroidism, mucocutaneous candidiasis and Addison's disease. It is caused by AutoImmune Regulator (AIRE) gene mutation. The diagnosis includes clinical manifestations in addition to AIRE gene sequencing. SPA type 2 presents with Addison's disease, type 1 diabetes, or autoimmune thyroid disease. Multiple genes have been implicated, including those of the class II major histocompatibility complex. SPA type 3 is characterized by autoimmune thyroid disease and other autoimmune disease, excluding Addison's disease and hypoparathyroidism, 4 genes have been implicated and confer susceptibility. The diagnosis of APS type 2 and type 3 includes clinical manifestations, nevertheless, the determination of autoantibodies can be useful to predict the risk of disease manifestation and to confirm the autoimmune disease in some cases.

Recurrent Concurrent Diabetic Ketoacidosis and Thyroid Storm

Diabetic ketoacidosis (DKA) and thyroid storm are serious complications of underlying disease states. Either condition can induce the other, and the co-occurrence of these conditions is uncommon. We present the case of an adolescent patient with type 1 diabetes and autoimmune hypothyroidism who developed recurrent concurrent DKA and thyroid storm twice in an eight-month period. The simultaneous development of DKA and thyroid storm is uncommon with only 28 cases previously reported. Co-presentation of these two life-threatening conditions occurs in people with either preexisting diabetes, thyroid disease, or both. The purported pathophysiology of how DKA and thyroid storm affect the other is discussed.

Type 1 Diabetes and Autoimmune Thyroid Disease-The Genetic Link

Type 1 diabetes (T1D) and autoimmune thyroid disease (AITD) are the most frequent chronic autoimmune diseases worldwide. Several autoimmune endocrine and non-endocrine disorders tend to occur together. T1D and AITD often cluster in individuals and families, seen in the formation of autoimmune polyendocrinopathy (AP). The close relationship between these two diseases is largely explained by sharing a common genetic background. The HLA antigens DQ2 (DQA1*0501-DQB1*0201) and DQ8 (DQA1*0301-DQB1*0302), tightly linked with DR3 and DR4, are the major common genetic predisposition. Moreover, functional single nucleotide polymorphisms (or rare variants) of various genes, such as the cytotoxic T-lymphocyte- associated antigen (CTLA4), the protein tyrosine phosphatase non-receptor type 22 (PTPN22), the interleukin-2 Receptor (IL2Ra), the Vitamin D receptor (VDR), and the tumor-necrosis-factor-α (TNF) that are involved in immune regulation have been identified to confer susceptibility to both T1D and AITD. Other genes including cluster of differentiation 40 (CD40), the forkhead box P3 (FOXP3), the MHC Class I Polypeptide-Related Sequence A (MICA), insulin variable number of tandem repeats (INS-VNTR), the C-Type Lectin Domain Containing 16A (CLEC16A), the Erb-B2 Receptor Tyrosine Kinase 3 (ERBB3) gene, the interferon-induced helicase C domain-containing protein 1 (IFIH1), and various cytokine genes are also under suspicion to increase susceptibility to T1D and AITD. Further, BTB domain and CNC homolog 2 (BACH2), C-C motif chemokine receptor 5 (CCR5), SH2B adaptor protein 3 (SH2B3), and Rac family small GTPase 2 (RAC2) are found to be associated with T1D and AITD by various independent genome wide association studies and overlap in our list, indicating a strong common genetic link for T1D and AITD. As several susceptibility genes and environmental factors contribute to the disease aetiology of both T1D and AITD and/or AP subtype III variant (T1D+AITD) simultaneously, all patients with T1D should be screened for AITD, and vice versa.

Thyroid hormones in diabetes, cancer, and aging

Thyroid function is central in the control of physiological and pathophysiological processes. Studies in animal models and human research have determined that thyroid hormones modulate cellular processes relevant for aging and for the majority of age‐related diseases. While several studies have associated mild reductions on thyroid hormone function with exceptional longevity in animals and humans, alterations in thyroid hormones are serious medical conditions associated with unhealthy aging and premature death. Moreover, both hyperthyroidism and hypothyroidism have been associated with the development of certain types of diabetes and cancers, indicating a great complexity of the molecular mechanisms controlled by thyroid hormones. In this review, we describe the latest findings in thyroid hormone research in the field of aging, diabetes, and cancer, with a special focus on hepatocellular carcinomas. While aging studies indicate that the direct modulation of thyroid hormones is not a viable strategy to promote healthy aging or longevity and the development of thyromimetics is challenging due to inefficacy and potential toxicity, we argue that interventions based on the use of modulators of thyroid hormone function might provide therapeutic benefit in certain types of diabetes and cancers.

Amino Acid Polymorphisms in Hla Class II Differentiate Between Thyroid and Polyglandular Autoimmunity

CONTEXT

The structure of the human leucocyte antigen (HLA) peptide-binding clefts strongly contributes to monoglandular and polyglandular autoimmunity (AP).

OBJECTIVE

To investigate the impact of amino acid polymorphisms on the peptide-binding interactions within HLA class II and its association with AP.

DESIGN

Immunogenetic study.

SETTING

Tertiary referral center for autoimmune endocrine diseases.

SUBJECTS

587 subjects with AP, autoimmune thyroid disease (AITD), type 1 diabetes (T1D), and healthy unrelated controls were typed for HLA class II.

METHODS

Amino acids within the peptide binding cleft that are encoded by HLA class II exon 2 were listed for all codon positions in all subjects. Overall comparisons between disease and control groups with respect to allele distribution at a given locus were performed by assembling rare alleles applying an exact Freeman Halton contingency table test with Monte-Carlo P values based on 150 000 samples.

RESULTS

The Monte Carlo exact Fisher test demonstrated marked differences in all 3 loci, DQA1, DQB1, and DRB1 (P < .0001) between AP and both AITD and controls, as well as between AP type II (Addison's disease as a major endocrine component) and AP type III (T1D + AITD). Differences were also noted between AP and T1D pertaining to the DRB1 allele (P < .041). Seven amino acid positions, DRB1-13, DRB1-26, DRB1-71, DRB1-74, DQA1-47, DQA1-56, and DQB1-57, significantly contributed to AP. Five positions in DQA1 (11, 47, 50, 56, and 69) completely correlated (P < .0001).

CONCLUSION

Amino acid polymorphisms within HLA class II exon 2 mediate the AP risk and differentiate between thyroid and polyglandular autoimmunity.

Therapeutic effect of mesenchymal stem cell on Hashimoto's thyroiditis in a rat model by modulating Th17/Treg cell balance

The autoimmune condition Hashimoto's thyroiditis (HT) is a disease wherein lymphocytes mediate the autoimmune damage and destruction of the thyroid gland. There are currently no effective means of treating HT, with the primary strategies of thyroid hormone therapy, surgery, or immunomodulatory therapy being associated with serious risks and side effects. There is thus a clear and urgent need to identify novel treatments for HT. In this study, we utilize female SD rats induced HT to evaluated the ability of transplanted MSCs to regulate Th17/Treg interactions in a rat Hashimoto's thyroiditis (HT) model system. The results showed that Rats in the HT model group exhibited increased thyroid autoantibody levels consistent with successful model development, whereas these levels were lower in rats treated with MSCs. There were also fewer thyroid lesions and less lymphoid infiltration of the thyroid in MSC-treated rats relative to HT model rats, as well as fewer Th17 cells and more Treg cells - an observation consistent with the cytokine analyses. All of these showed that MSCs can regulate Th17/Treg interactions in a rat Hashimoto's thyroiditis (HT) model system. It suggested that transplanted MSCs could be a potential immunotherapy strategy for the treatment of Hashimoto's thyroiditis.

Autoimmune polyglandular diseases

Autoimmune polyglandular diseases (APD) are defined as the presence of two autoimmune -induced endocrine failures. With respect to the significant morbidity and potential mortality of APD, the diagnostic objective is to detect APD at an early stage, with the advantage of less frequent complications, effective therapy and better prognosis. This requires that patients at risk be regularly screened for subclinical endocrinopathies prior to clinical manifestation. Regarding the time interval between manifestation of first and further endocrinopathies, regular and long-term follow-up is warranted. Quality of life and psychosocial status are poor in APD patients and involved relatives. Familial clustering is high in patients with APD. Considering the high incidence of one or more endocrinopathies in first-degree relatives of patients with APD, family members should be regularly screened since they may also develop autoimmune endocrinopathies. Multidisciplinary management of these multiplex families in specialized centers is warranted.

Autoimmune Polyendocrinopathy

CONTEXT

This mini-review offers an update on the rare autoimmune polyendocrinopathy (AP) syndrome with a synopsis of recent developments.

DESIGN AND RESULTS

Systematic search for studies related to pathogenesis, immunogenetics, screening, diagnosis, clinical spectrum, and epidemiology of AP. AP (orphan code ORPHA 282196) is defined as the autoimmune-induced failure of at least two glands. AP is divided into the rare juvenile type I and the adult types II to IV. The prevalence is 1:100,000 and 1:20,000 for types I and types II to IV, respectively. Whereas type I (ORPHA 3453) is a monogenetic syndrome with an autosomal recessive transmission related to mutations in the autoimmune regulator (AIRE) gene, types II to IV are genetically complex multifactorial syndromes that are strongly associated with certain alleles of HLA genes within the major histocompatibility complex located on chromosome 6, as well as the cytotoxic T lymphocyte antigen 4 and the protein tyrosine phosphatase nonreceptor type 22 genes. Addison disease is the major endocrine component of type II (ORPHA 3143), whereas the coexistence of type 1 diabetes and autoimmune thyroid disease is characteristic for type III (ORPHA 227982). Genetic screening for the AIRE gene is useful in patients with suspected type I, whereas serological screening (i.e., diabetes/adrenal antibodies) is required in patients with monoglandular autoimmunity and suspected AP. If positive, functional endocrine testing of the antibody-positive patients as well as serological screening of their first-degree relatives is recommended.

CONCLUSION

Timely diagnosis, genetic counseling, and optimal long-term management of AP is best offered in specialized centers.

Thyroid Dysfunction and Diabetes Mellitus: Two Closely Associated Disorders

Thyroid dysfunction and diabetes mellitus are closely linked. Several studies have documented the increased prevalence of thyroid disorders in patients with diabetes mellitus and vice versa. This review critically discusses the different underlying mechanisms linking type 1 and 2 diabetes and thyroid dysfunction to demonstrate that the association of these two common disorders is unlikely a simple coincidence. We assess the current state of knowledge on the central and peripheral control of thyroid hormone on food intake and glucose and lipid metabolism in target tissues (such as liver, white and brown adipose tissue, pancreatic β cells, and skeletal muscle) to explain the mechanism linking overt and subclinical hypothyroidism to type 2 diabetes and metabolic syndrome. We also elucidate the common susceptibility genes and the pathogenetic mechanisms contributing to the autoimmune mechanism involved in the onset of type 1 diabetes mellitus and autoimmune thyroid disorders. An untreated thyroid dysfunction can impair the metabolic control of diabetic patients, and this association can have important repercussions on the outcome of both of these disorders. Therefore, we offer recommendations for the diagnosis, management, and screening of thyroid disorders in patients with diabetes mellitus, including the treatment of diabetic patients planning a pregnancy. We also discuss the major causes of failure to achieve an optimal management of thyroid dysfunction in diabetic patients and provide recommendations for assessing and treating these disorders during therapy with antidiabetic drugs. An algorithm for a correct approach of these disorders when linked is also provided.

Co-Occurrence of Multiple Endocrine Abnormalities Induced by the DIHS/DRESS

BACKGROUND

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS) is a severe adverse reaction caused by specific drugs. However, little information is available about sequelae following DIHS/DRESS resolution from an endocrinologist's perspective. This study aimed to investigate the endocrine sequelae following DIHS/DRESS, from clinical feature to etiology.

METHODS

We retrospectively analyzed the patients diagnosed with DIHS/DRESS in Peking Union Medical College Hospital (PUMCH) during the period of 1 January 2012 to 31 December 2017, and those who developed endocrine disorders after DIHS/DRESS were further examined. We also reviewed the literature, from 1 January 2000 to 31 December 2017, on involvement of endocrine glands in DIHS/DRESS patients.

RESULTS

Three patients developed both autoimmune thyroid disease (AITD) and type 1 diabetes (T1DM)/fulminant type 1 diabetes (FT1DM) of the 45 patients. Seven cases involving more than two endocrine glands were reported in the literature. Our results indicated that DIHS/DRESS is a potential etiological factor of autoimmune polyendocrine syndrome (APS), especially APS III.

CONCLUSIONS

Patients require careful long-term follow-up after DIHS/DRESS. Involvement of endocrine glands, especially FT1DM, should always be monitored in patients with a history of DIHS/DRESS. This study indicated that DIHS/DRESS could lead to APS, especially APS III, providing novel insights into the etiological factors of APS.

Premature ovarian failure, short stature, and Hashimoto's disease in an 18-year-old adolescent girl with 46, X, i(X)(q10)

Premature ovarian failure (POF) is a heterogeneous condition affecting girls and women. We detected a previously healthy 18-year-old adolescent girl, presented with amenorrhea over six months, as well as circulating levels of estradiol lower decreased and follicle-stimulating hormone (FSH) increased. She was 138 cm tall. Results of laboratory tests and/or ultrasound investigations showed 46, X, i(X)(q10) karyotype and Hashimoto's disease. This case suggests that pubertal onset and progression, as well as karyotype analysis, should be evaluated in girls with Hashimoto's disease and short stature.

Celiac disease and endocrine autoimmunity - the genetic link

Celiac disease is a small intestinal inflammatory disease with autoimmune features that is triggered and maintained by the ingestion of the storage proteins (gluten) of wheat, barley and rye. The prevalence of celiac disease is increased in patients with monoglandular and/or polyglandular autoimmunity and their relatives. Between 10 and 30% of patients with celiac disease are thyroid and/or type 1 diabetes antibody positive, while around 5 to 7% of patients with autoimmune thyroid disease and/or type 1 diabetes are IgA anti-tissue transglutaminase antibody positive. The close relationship between celiac disease and endocrine autoimmunity is largely explained by sharing a common genetic background. The HLA antigens DQ2 (DQA1*0501-DQB1*0201) and/or DQ8 (DQA1*0301-DQB1*0302), that are tightly linked to DR3 and DR4, respectively, are the major common genetic predisposition. Moreover, functional single nucleotide polymorphisms of various genes that are involved in immune regulation have been identified as "overlap" susceptibility genes for both celiac disease and monoglandular or polyglandular autoimmunity. While plausible, it remains to be established how far a gluten free diet may prevent or ameliorate glandular autoimmunity. In conclusion, all patients with celiac disease should be screened for type 1 diabetes and/or autoimmune thyroid disease. Conversely, patients with the above autoimmune endocrine disorders should be also screened for celiac disease.

PTPN22 and CTLA-4 Polymorphisms Are Associated With Polyglandular Autoimmunity

CONTEXT

Single nucleotide polymorphisms (SNPs) of various genes increase susceptibility to monoglandular autoimmunity. Data on autoimmune polyglandular syndromes (APSs) are scarce.

OBJECTIVE

Evaluate potential associations of eight SNPs with APSs.

SETTING

Academic referral endocrine clinic.

PATIENTS

A total of 543 patients with APS and monoglandular autoimmunity and controls.

INTERVENTION

The SNP protein tyrosine phosphatase nonreceptor type 22 (PTPN22) rs2476601 (+1858); cytotoxic T-lymphocyte‒associated antigen 4 (CTLA-4) rs3087243 (CT60) and rs231775 (AG49); vitamin D receptor (VDR) rs1544410 (Bsm I), rs7975232 (Apa I), rs731236 (Taq I); tumor necrosis factor α rs1800630 (-863); and interleukin-2 receptor alpha rs10795791 were tested by single-base extension in all subjects.

RESULTS

The PTPN22 +1858 allele and genotype distribution were markedly different between APS, type 1 diabetes [T1D; odds ratio (OR): 2.67; 95% confidence interval (CI): 1.52 to 4.68; P = 0.001], Graves disease (GD; OR: 1.94; 95% CI: 1.16 to 3.25; P = 0.011), and controls (OR: 3.31, 95% CI: 1.82 to 6.02; P < 0.001). T-allele carriers' risk for APS was increased (OR: 3.76; 95% CI: 1.97 to 7.14; P < 0.001). T-allele frequency was higher among APS than controls (OR: 3.25; 95% CI: 1.82 to 5.82; P < 0.001), T1D (OR: 2.54; 95% CI: 1.48 to 4.36; P = 0.001), or GD (OR: 1.89; 95% CI: 1.15 to 3.11; P = 0.012). The SNP CTLA-4 CT60 G-allele carriers were more frequent in APS (85%) than controls (78%) (OR: 1.55; 95% CI: 0.81 to 2.99). Combined analysis of CTLA-4 AG49 and CT60 revealed OR 4.89; 95% CI: 1.86 to13.59; P = 0.00018 of the genotype combination AG/GG for APS vs controls. VDR polymorphisms Bsm I, Apa I, and Taq I did not, but the haplotypes differed between APS and controls (P = 0.0011).

CONCLUSIONS

PTPN22 and CTLA-4 polymorphisms are associated with APS and differentiate between polyglandular and monoglandular autoimmunity.

Concurrent variant type 3 autoimmune polyglandular syndrome and pulmonary arterial hypertension in a Japanese woman

We describe a very rare case of concurrent variant type 3 autoimmune polyglandular syndrome (APS) and pulmonary arterial hypertension (PAH). A previously healthy 65-year-old Japanese woman was referred to our university hospital with a 2-month history of general fatigue and hyperglycemia. Laboratory tests revealed severe hyperglycemia (plasma glucose 543 mg/dL and HbA1c 10.7%) with ketonuria (3+). Glutamic acid decarboxylase (GAD) and IA-2 antibodies were positive, and the serum C peptide level was markedly decreased to 0.2 ng/mL. Accordingly, type 1 diabetes was diagnosed. Hashimoto's thyroiditis was also diagnosed because she had a diffuse goiter and a mild hypothyroidism (TSH 8.20 μU/mL, and FT4 0.80 ng/mL) with positive autoantibodies for thyroid peroxidase and thyroglobulin. There was neither adrenal insufficiency nor hypocalcemia. In addition, chest X ray showed a suspicious PAH by a dilation of both pulmonary arteries, especially right descending artery, and right heart catheterization confirmed the presence of PAH. HLA Class II genotyping revealed DRB1-DQB1*0901-*0303, a common susceptibility haplotype in Japanese patients with type 3 APS or acute-onset type 1 diabetes. The combination of variant type 3 APS and PAH is extremely rare and to the best of knowledge, this is the first case reported in a Japanese patient.

Polyglandular autoimmune syndromes

BACKGROUND

In recent years, scientific knowledge pertaining to the rare ORPHAN polyglandular autoimmune syndrome (registered code ORPHA 282196) has accumulated.

OBJECTIVE

To offer current demographic, clinical, serological and immunogenic data on PAS.

METHODS

Review of the pertinent and current literature.

RESULTS

Polyglandular autoimmune syndromes (PAS) are multifactorial diseases with at least two coexisting autoimmune-mediated endocrinopathies. PAS show a great heterogeneity of syndromes and manifest sequentially with a large time interval between the occurrence of the first and second glandular autoimmune disease. PAS cluster with several non-endocrine autoimmune diseases. In most endocrinopathies of PAS, the autoimmune process causes an irreversible loss of function, while chronic autoimmune aggressions can simultaneously modify physiological processes in the affected tissue and lead to altered organ function. The rare juvenile PAS type I is inherited in a monogenetic manner, whereas several susceptibility gene polymorphisms have been reported for the more prevalent adult types. Relevant for a timely diagnosis at an early stage is the screening for polyglandular autoimmunity in patients with monoglandular autoimmune disease and/or first degree relatives of patients with PAS. The most prevalent adult PAS type is the combination of type 1 diabetes with autoimmune thyroid disease.

CONCLUSIONS

Early detection of specific autoantibodies and latent organ-specific dysfunction is advocated to alert physicians to take appropriate action in order to prevent full-blown PAS disease.

Latent autoimmune diabetes of adulthood: case report

BACKGROUND

Primary care clinicians will see a higher incidence of type 2 diabetes in adult patients, and the diagnosis and management of an initial presentation of type 1 diabetes can pose challenges to clinicians who see it less frequently. Symptoms of hyperglycemia and risk of ketoacidosis may be missed. Further, endocrine autoimmune disease can run together in patients and families.

CASE PRESENTATION

A 49-year-old Caucasian female with history of pituitary adenoma and Graves' disease with history of thyroid ablation presented in the outpatient setting due to hand tingling of her right middle finger that was worse in the mornings and improved throughout the day. She also complained of excessive thirst, finding herself drinking more water than usual and waking up in the night to urinate. There was no dysuria or haematuria, and no other neurologic symptoms. She did report feeling hungry. She had no family history of diabetes, normal body mass index of 21.7, and reported taking her thyroid replacement medication every day. The differential diagnosis for her thirst included dehydration, psychogenic polydipsia, diabetes mellitus, diabetes insipidus, and anxiety. The patient had normal vital signs and was well appearing; labs were ordered for her on her way home from clinic with no medications. Labs revealed a random blood glucose level of 249 mg/dL, normal renal function, a normal B12 of 996 pg/mL, and an elevated thyroid stimulating hormone level of 25.67 u[iU]/mL. On follow up with her primary care provider 5 days later, additional labs were drawn showing A1C of 11.5%, 1+ ketonuria, a negative Acetest, and a normal basic metabolic panel, except for a fasting glucose of 248 mg/dL, and Free T3 of 2.42 pg/mL, and Free T4 of 1.7 ng/dL. Islet cell antibodies and glutamic acid decarboxylase antibodies were both positive, consistent with type 1 diabetes. She was started on insulin and improved.

CONCLUSION

Given the patient's age, this is a less common presentation of type 1 diabetes mellitus, as a part of polyglandular autoimmune syndrome type IIIa. It serves as a reminder that clinicians should remember that patients with one autoimmune disease (in this case, h/o Graves' disease) are at higher risk for diabetes and other endocrine autoimmune diseases and should be screened appropriately. Clinicians should keep latent type 1 diabetes in the differential in adulthood to ensure proper and timely treatment.

Use of short interfering RNA delivered by cationic liposomes to enable efficient down-regulation of PTPN22 gene in human T lymphocytes

Type 1 diabetes and thyroid disease are T cell-dependent autoimmune endocrinopathies. The standard substitutive administration of the deficient hormones does not halt the autoimmune process; therefore, development of immunotherapies aiming to preserve the residual hormonal cells, is of crucial importance. PTPN22 C1858T mutation encoding for the R620W lymphoid tyrosine phosphatase variant, plays a potential pathophysiological role in autoimmunity. The PTPN22 encoded protein Lyp is a negative regulator of T cell antigen receptor signaling; R620W variant, leading to a gain of function with paradoxical reduced T cell activation, may represent a valid therapeutic target. We aimed to develop novel wild type PTPN22 short interfering RNA duplexes (siRNA) and optimize their delivery into Jurkat T cells and PBMC by using liposomal carriers. Conformational stability, size and polydispersion of siRNA in lipoplexes was measured by CD spectroscopy and DLS. Lipoplexes internalization and toxicity evaluation was assessed by confocal microscopy and flow cytometry analysis. Their effect on Lyp expression was evaluated by means of Western Blot and confocal microscopy. Functional assays through engagement of TCR signaling were established to evaluate biological consequences of down-modulation. Both Jurkat T cells and PBMC were efficiently transfected by stable custom lipoplexes. Jurkat T cell morphology and proliferation was not affected. Lipoplexes incorporation was visualized in CD3+ but also in CD3- peripheral blood immunotypes without signs of toxicity, damage or apoptosis. Efficacy in affecting Lyp protein expression was demonstrated in both transfected Jurkat T cells and PBMC. Moreover, impairment of Lyp inhibitory activity was revealed by increase of IL-2 secretion in culture supernatants of PBMC following anti-CD3/CD28 T cell receptor-driven stimulation. The results of our study open the pathway to future trials for the treatment of autoimmune diseases based on the selective inhibition of variant PTPN22 allele using lipoplexes of siRNA antisense oligomers.

Flexible peptide recognition by HLA-DR triggers specific autoimmune T-cell responses in autoimmune thyroiditis and diabetes

Autoimmune polyglandular syndrome 3 variant (APS3v) refers to the co-occurrence of autoimmune thyroiditis (AITD) and type 1 diabetes (T1D) within the same individual. HLA class II confers the strongest susceptibility to APS3v. We previously identified a unique amino acid signature of the HLA-DR pocket (designated APS3v HLA-DR pocket) that predisposes to APS3v. We hypothesized that both thyroid and islet peptides can be presented by the unique APS3v HLA-DR pocket, triggering AITD + T1D together. To test this hypothesis we screened islet and thyroid peptides for their ability to bind to the APS3v HLA-DR pocket. Virtual screen of all possible thyroglobulin (Tg), thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase (TPO), insulin (Ins), and glutamic acid decarboxylase 65 (GAD65) peptides identified 36 peptides that bound to this unique pocket. In vitro binding assays using baculovirus-produced recombinant APS3v HLA-DR identified 11 thyroid/islet peptides (of the 36 predicted binders) that bound with high affinity. By immunizing humanized HLA-DR3 mice carrying the APS3v HLA-DR pocket we identified 4 peptides (Tg.1571, GAD.492, TPO.758, TPO.338) that were presented by antigen presenting cells and elicited T-cell response. We conclude that both thyroid and islet peptides can bind to this flexible APS3v HLA-DR pocket and induce thyroid and islet specific T-cell responses. These findings set the stage to developing specific inhibitors of the APS3v HLA-DR pocket as a precision medicine approach to treating or preventing APS3v in patients that carry this genetic HLA-DR pocket variant.

Type 1 diabetes associated autoimmunity

Diabetes mellitus is increasing in prevalence worldwide. The economic costs are considerable given the cardiovascular complications and co-morbidities that it may entail. Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by the loss of insulin-producing pancreatic β-cells. The pathogenesis of T1D is complex and multifactorial and involves a genetic susceptibility that predisposes to abnormal immune responses in the presence of ill-defined environmental insults to the pancreatic islets. Genetic background may affect the risk for autoimmune disease and patients with T1D exhibit an increased risk of other autoimmune disorders such as autoimmune thyroid disease, Addison's disease, autoimmune gastritis, coeliac disease and vitiligo. Approximately 20%-25% of patients with T1D have thyroid antibodies, and up to 50% of such patients progress to clinical autoimmune thyroid disease. Approximately 0.5% of diabetic patients have concomitant Addison's disease and 4% have coeliac disease. The prevalence of autoimmune gastritis and pernicious anemia is 5% to 10% and 2.6% to 4%, respectively. Early detection of antibodies and latent organ-specific dysfunction is advocated to alert physicians to take appropriate action in order to prevent full-blown disease. Patients and family members should be educated to be able to recognize signs and symptoms of underlying disease.

High frequency of vitamin D receptor gene polymorphism FokI in Brazilian Type 1 diabetes mellitus patients with clinical autoimmune thyroid disease

BACKGROUND

Polymorphisms of vitamin D receptor (VDR) gene have been studied as genetic markers of type 1 diabetes mellitus (T1DM) and some studies have reported associations with autoimmune thyroid disease. The aim of this study was to evaluate the relationship between VDR FokI polymorphism (rs10735810), thyroid autoimmunity and thyroid dysfunction (TD) in Brazilian T1DM.

METHODS

One-hundred-eighty T1DM patients were evaluated for age, duration of diabetes (DDM), positivity to TPO Antibody (TPOA), GAD Antibody (GADA), IA2 Antibody (IA2A) and fasting serum C-peptide (FCP) according to diagnosis of TD. PCR-RFLP analyses were carried out for VDR polymorphism FokI.

RESULTS

TPOA positivity (80.0 vs. 25.0 %, p < 0.001) and GADA positivity (56.0 vs. 30.3 %, p = 0.01) were higher in T1DM patients with TD with the same age and DDM than the group without TD, with no difference of FCP and IA2A positivity. We observed higher prevalence of VDR FokI in T1DM with TD (ff and Ff 73.9 % with TD vs. 52.7 % without TD, p = 0.05). Positivity to TPOA and presence of FokI polymorphism were significantly associated with the concurrence of TD in T1DM patients (OR 18.1; CI 3.7-87.0; p < 0.001).

CONCLUSIONS

The VDR FokI polymorphism (rs10735810) was associated to persistence of GADA, TPOA positivity and TD in Brazilian T1DM. Positivity to TPOA and VDR polymorphism FokI were strongly associated with concurrence of T1D and TD. These data collaborate to understanding the joint susceptibility genes for TD in T1DM.

Genome wide identification of new genes and pathways in patients with both autoimmune thyroiditis and type 1 diabetes

Autoimmune thyroid diseases (AITD) and Type 1 diabetes (T1D) frequently occur in the same individual pointing to a strong shared genetic susceptibility. Indeed, the co-occurrence of T1D and AITD in the same individual is classified as a variant of the autoimmune polyglandular syndrome type 3 (designated APS3v). Our aim was to identify new genes and mechanisms causing the co-occurrence of T1D + AITD (APS3v) in the same individual using a genome-wide approach. For our discovery set we analyzed 346 Caucasian APS3v patients and 727 gender and ethnicity matched healthy controls. Genotyping was performed using the Illumina Human660W-Quad.v1. The replication set included 185 APS3v patients and 340 controls. Association analyses were performed using the PLINK program, and pathway analyses were performed using the MAGENTA software. We identified multiple signals within the HLA region and conditioning studies suggested that a few of them contributed independently to the strong association of the HLA locus with APS3v. Outside the HLA region, variants in GPR103, a gene not suggested by previous studies of APS3v, T1D, or AITD, showed genome-wide significance (p < 5 × 10(-8)). In addition, a locus on 1p13 containing the PTPN22 gene showed genome-wide significant associations. Pathway analysis demonstrated that cell cycle, B-cell development, CD40, and CTLA-4 signaling were the major pathways contributing to the pathogenesis of APS3v. These findings suggest that complex mechanisms involving T-cell and B-cell pathways are involved in the strong genetic association between AITD and T1D.

The diagnosis and treatment of celiac disease

BACKGROUND

Celiac disease is an inflammatory disease of, the small intestine with a prevalence of roughly 0.5%-1%. Its symptoms arise in response to gluten consumption by genetically predisposed persons (HLA-DQ2/8). The autoantigen tissue transglutaminase (TG2) plays an important role in the pathogenesis of celiac disease.

METHOD

Selective review of pertinent literature, including guidelines from Germany and abroad.

RESULTS

Celiac disease can present at any age with gastrointestinal or extraintestinal manifestations (e.g., malabsorption or Duhring's dermatitis herpetiformis); it can also be found in association with other (auto-)immune diseases, such as type 1 diabetes. Most cases are oligosymptomatic. The wide differential diagnosis includes food intolerances, intestinal infections, and irritable bowel syndrome, among other conditions. The definitive diagnosis requires the demonstration of celiac disease-specific autoantibody to TG2 (endomysium), which is over 90% sensitive and far over 90% specific, and the characteristic histologic lesions of the small-bowel mucosa and remission on a gluten-free diet.

CONCLUSION

An understanding of celiac disease ought to inform everyday clinical practice in all medical disciplines, because this is a common condition with diverse manifestations that can be effectively diagnosed and easily treated for the prevention of both acute and long-term complications. Patients should follow a strictly gluten-free diet for life.

Altered B cell homeostasis and toll-like receptor 9-driven response in type 1 diabetes carriers of the C1858T PTPN22 allelic variant: implications in the disease pathogenesis

Type 1 diabetes is an autoimmune disease caused by the destruction of pancreatic beta cells by autoreactive T cells. Among the genetic variants associated with type 1 diabetes, the C1858T (Lyp) polymorphism of the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene alters the function of T cells but also of B cells in innate and adaptive immunity. The Lyp variant was shown to diminish interferon production and responses upon Toll-like receptor stimulation in macrophages and dendritic cells, possibly leading to uncontrolled infections as triggers of the diabetogenic process. The aim of this study was to unravel the yet uncharacterized effects that the variant could exert on the immune and autoimmune responses, particularly regarding the B cell phenotype, in the peripheral blood lymphocytes of diabetic patients and healthy controls in basal conditions and after unmethylated bacterial DNA CpG stimulation. The presence of the Lyp variant resulted in a significant increase in the percentage of transitional B cells in C/T carriers patients and controls compared to C/C patients and controls, in C/T carrier patients compared to C/C controls and in C/T carrier patients compared to C/C patients. A significant reduction in the memory B cells was also observed in the presence of the risk variant. After four days of CpG stimulation, there was a significant increase in the abundance of IgM+ memory B cells in C/T carrier diabetics than in C/C subjects and in the groups of C/T carrier individuals than in C/C individuals. IgM- memory B cells tended to differentiate more precociously into plasma cells than IgM+ memory B cells in heterozygous C/T subjects compared to the C/C subjects. The increased Toll-like receptor response that led to expanded T cell-independent IgM+ memory B cells should be further investigated to determine the putative contribution of innate immune responses in the disease pathogenesis.

Compromised central tolerance of ICA69 induces multiple organ autoimmunity

For reasons not fully understood, patients with an organ-specific autoimmune disease have increased risks of developing autoimmune responses against other organs/tissues. We identified ICA69, a known β-cell autoantigen in Type 1 diabetes, as a potential common target in multi-organ autoimmunity. NOD mice immunized with ICA69 polypeptides exhibited exacerbated inflammation not only in the islets, but also in the salivary glands. To further investigate ICA69 autoimmunity, two genetically modified mouse lines were generated to modulate thymic ICA69 expression: the heterozygous ICA69(del/wt) line and the thymic medullary epithelial cell-specific deletion Aire-ΔICA69 line. Suboptimal central negative selection of ICA69-reactive T-cells was observed in both lines. Aire-ΔICA69 mice spontaneously developed coincident autoimmune responses to the pancreas, the salivary glands, the thyroid, and the stomach. Our findings establish a direct link between compromised thymic ICA69 expression and autoimmunity against multiple ICA69-expressing organs, and identify a potential novel mechanism for the development of multi-organ autoimmune diseases.

The putative role of proteolytic pathways in the pathogenesis of Type 1 diabetes mellitus: the 'autophagy' hypothesis

Autoimmune diseases are a heterogeneous group of disorders affecting different organs and tissues. New tools, such as genome-wide association studies, have provided evidence for new susceptibility loci and candidate genes in the disease process including common susceptibility genes involved in the immunological synapse and T cell activation. Close linkages have been found in a number of diseases, including ankylosing spondylitis, multiple sclerosis, Crohn's disease and insulin-dependent diabetes mellitus (Type 1 diabetes mellitus). Evidence for some association with Type 1 diabetes was previously found in the region containing 5q15/ERAP1 (endoplasmic reticulum aminopeptidase 1) (rs30187, ARTS1). Recent data suggest that in eukaryotic cells in addition to the ubiquitin/proteasome system another proteolytic pathway may have a significant role in the autoimmunity process, i.e. the autophagic pathway which constitutes the principal regulated catabolic process mediated by lysosomes. Autophagy could play a role in MHC class I and class II self-antigen presentation at the basis of the autoimmunity process. Furthermore cross-talk among different proteolytic pathways was recently highlighted i.e. components processed in the ubiquitin/proteasome system possibly engaged in autophagic pathways. T1D is an autoimmune disease characterised by the destruction of pancreatic beta cells by autoreactive T cells. Immunological abnormalities can precede months to years the initial symptoms and clinical diagnosis. Our hypothesis suggests that in the autoimmune process autophagy can intervene at different levels, during the thymic selection process of T lymphocytes causing escape of autoreactive T cells, at the initiation stage of the disease, in the preclinical period or subsequently to the disease onset having a role at the level of perpetuation of the autoimmunity process. Supporting evidence derives from the already reported discovery of polymorphisms in autophagy-related genes in patients affected by several autoimmune conditions such as Systemic Lupus Erithematosus. In addition deregulated autophagy was detected in T cells from lupus-prone mice and also found in T cells from patients. Autophagy was found activated in osteoclasts from RA patients as demonstrated by the increased expression of Atg7 and Beclin-1. Our hypothesis to be unraveled could have, if correct, relevant implications for the management of autoimmune conditions such as Type 1 diabetes. In principle, novel therapeutic approaches could be established by targeting deregulated autophagy offering novel opportunities to personalized medicine in patients affected by the disease.

HLA class II haplotypes differentiate between the adult autoimmune polyglandular syndrome types II and III

BACKGROUND

Genetics of the adult autoimmune polyglandular syndrome (APS) is poorly understood.

AIM

The aim of this study was to gain further insight into the genetics of the adult APS types. SITE: The study was conducted at a university referral center.

METHODS

The human leukocyte antigen (HLA) class II alleles, haplotypes, and genotypes were determined in a large cohort of patients with APS, autoimmune thyroid disease (AITD), and type 1 diabetes and in healthy controls by the consistent application of high-resolution typing at a four-digit level.

RESULTS

Comparison of the allele and haplotype frequencies significantly discriminated patients with APS vs AITD and controls. The HLA class II alleles DRB1*03:01 *04:01, DQA1*03:01, *05:01, DQB1*02:01, and *03:02 were observed more frequently (P<.001) in APS than in AITD and controls, whereas the alleles DRB1*15:01, DQB1*03:01, and *06:02 were underrepresented in APS vs AITD (Pc<.001) and controls (Pc<.01), respectively. The DRB1*03:01-DQA1*05:01-DQB1*02:01 (DR3-DQ2) and DRB1*04:01-DQA1*03:01:DQB1*03:02 (DRB1*04:01-DQ8) haplotypes were overrepresented in APS (Pc<.001). Combination of both haplotypes to a genotype was highly prevalent in APS vs AITD and controls (Pc<.001). Dividing the APS collective into those with Addison's disease (APS type II) and those without Addison's disease but including type 1 diabetes and AITD (APS type III) demonstrated DR3-DQ2/DRB1*04:01-DQ8 as a susceptibility genotype in APS III (Pc<.001), whereas the DR3-DQ2/DRB1*04:04-DQ8 genotype correlated with APS II (Pc<.001). The haplotypes DRB1*11:01-DQA1*05:05-DQB1*03:01 and DRB1*15:01-DQA1*01:02-DQB1*06:02 are protective in APS III but not in type II (Pc<.01).

CONCLUSIONS

HLA class II haplotypes differentiate between the adult APS types II and III. Susceptible haplotypes favor the development of polyglandular autoimmunity in patients with AITD.

Analysis of the autoimmune regulator gene in patients with autoimmune non-APECED polyendocrinopathies

The pathogenesis of autoimmunity was derived from a complex interaction of genetic and environmental factors. Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy is a rare autosomal recessive disease caused by mutations in the autoimmune regulator (AIRE) gene. AIRE gene variants and, in particular, heterozygous loss-of-function mutations were also discovered in organ-specific autoimmune disorders, possibly contributing to their etiopathogenesis. It was suggested that even predisposition to develop certain autoimmune conditions may be derived from AIRE gene polymorphisms including S278R and intronic IVS9+6 G>A. In this study we unravel the hypothesis on whether AIRE gene variants may predispose individuals to associated autoimmune conditions in 41 Italian patients affected by non-APECED autoimmune polyendocrinopathies. We could not detect any heterozygous mutations of the AIRE gene. Although a trend of association was observed, heterozygous polymorphisms S278R and IVS9+6 G>A were detected in patients without statistically significant prevalence than in controls. Their putative contribution to autoimmune polyendocrinopathies and their predictive value in clinical strategies of disease development could be unravelled by analysing a larger sample of diseased patients and healthy individuals.

Mechanism of human chorionic gonadotrophin-mediated immunomodulation in pregnancy

Human chorionic gonadotrophin (hCG) is released within hours of fertilization and has a profound ability to downregulate maternal cellular immunity against trophoblastic paternal antigens. It also promotes angiogenic activity of the extravillous trophoblast, and impairment of this function may lead to inadequate placentation and an increased risk of preeclampsia. There is increasing evidence that hCG alters the activity of dendritic cells via an upregulation of indoleamine 2,3-dioxygenase activity. This reduces T-cell activation and cytokine production, as well as encouraging Treg cell recruitment to the fetal-maternal interface. These changes are critical in promoting maternal tolerance. hCG is also able to increase the proliferation of uterine natural killer cells, while reducing the activity of cytotoxic peripheral blood natural killer cells. There are rare reports of autoantibodies directed against hCG or the luteinizing hormone/hCG receptor in women with recurrent miscarriage. These autoantibodies are more frequent in women with thyroid autoimmunity. This may explain the association between thyroid autoimmunity and impaired fertility. Downregulating these anti-hCG and anti-luteinizing hormone/hCG receptor autoantibodies may be helpful in some women with early miscarriage or recurrent failed in vitro fertilization.

Simultaneous occurrence of type 1 diabetes mellitus and Graves' disease: a report of two cases and a review of the literature

Two unrelated Japanese women, 41 and 27 years of age, were admitted with histories of thirst, weight loss and palpitations of a few weeks' duration. Both were diagnosed to have diabetic ketosis or ketoacidosis with acute-onset type 1 diabetes (T1D) and Graves' disease (GD) (autoimmune polyglandular syndrome type 3 variant; APS3v), and were treated with intensive insulin therapy and anti-thyroid drugs. Human leukocyte antigen examinations showed that both cases had the HLA-A2, A24, B54, and DRB1*04:05-DQA1*03:03-DQB1*04:01 haplotype, which made them susceptible not only to APS3v, but also to both acute-onset T1D and GD. The genetic background of patients strongly contributes to the simultaneous occurrence of T1D and GD.

The putative role of the C1858T polymorphism of protein tyrosine phosphatase PTPN22 gene in autoimmunity

Autoimmune diseases represent a heterogeneous group of conditions whose incidence is increasing worldwide. This has stimulated studies on their etiopathogenesis, derived from a complex interaction between genetic and environmental factors, in order to improve prevention and treatment of these diseases. An increasing amount of epidemiologic investigations has associated the presence of the C1858T polymorphism in the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene to the onset of several autoimmune diseases including insulin-dependent diabetes mellitus (Type 1 diabetes). PTPN22 encodes for the lymphoid tyrosine phosphatase Lyp. This belongs to non-receptor-type protein tyrosine phosphatases involved in lymphocyte activation and differentiation. In humans, Lyp may have a role in the negative regulation of T cell receptor signaling. The single nucleotide polymorphism C1858T encodes for a more active phosphatase Lyp R620W. This has the ability to induce a higher negative regulation of T cell receptor signaling. Thus, C1858T could play an important role at the level of thymocyte polarization and escape of autoreactive T lymphocytes, through the positive selection of otherwise negatively selected autoimmune T cells. In this review we discuss the physiological role exerted by the PTPN22 gene and its encoded Lyp product in lymphocyte processes. We highlight the pathogenic significance of the C1858T PTPN22 polymorphism in human autoimmunity with special reference to Type 1 diabetes. Recently the genetic variation in PTPN22 was shown to induce altered function of T and B-lymphocytes. In particular BCR signaling defects and alterations in the B cell compartment were reported in T1D patients. We finally speculate on the possible development of novel therapeutic treatments in human autoimmunity aiming to selectively target the variant Lyp protein in autoreactive T and B lymphocytes.

The various faces of autoimmune endocrinopathies: non-tumoral hypergastrinemia in a patient with lymphocytic colitis and chronic autoimmune gastritis

Serum gastrin levels exceeding 1000pg/ml (normal, <100) usually raise the suspicion for a neuroendocrine tumor (NET) that secretes gastrin. Rarely, such elevated gastrin levels are seen in patients with pernicious anemia which most commonly is associated with autoimmune gastritis (AG). AG can occur concomitantly with other autoimmune disorders including lymphocytic colitis (LC). Gastrin stimulates enterochromaffin-like cells which increase histamine secretion. Histamine excess can cause diarrhea as can bacterial overgrowth or LC. We present a 57-year-old woman with diarrhea, sporadic epigastric pain, and bloating. She also had a history of interstitial cystitis and took pentosan polysulfate and cetirizine. She had no history of ulcers, renal impairment or carcinoid syndrome. Fasting serum gastrin was 1846pg/ml. Esophagoduodenal gastroscopy and biopsies revealed chronic gastritis and a pH of 7 with low stomach acid. Serum gastrin and plasma chromogranin A were suggestive of a gastrinoma or NET. Pernicious anemia was unlikely. Imaging studies did not reveal any tumor. Random colonic biopsy was compatible with LC, possibly explaining her diarrhea, although we also considered excessive histamine from elevated gastrin, bacterial overgrowth, and pentosan polysulfate which can cause diarrhea and be misleading in this setting, pointing to the diagnosis of gastrinoma. At 4year follow-up in 2012, fasting serum gastrin was 1097pg/ml and the patient asymptomatic taking only cetirizine for nasal allergies. This case illustrates that diarrhea may be associated with very high serum gastrin levels in the setting of chronic gastritis, LC, and interstitial cystitis (pentosan use), without clear evidence for a gastrinoma or NET. If no history of ulcers or liver metastases is present in such cases, watchful observation rather than an extensive/invasive and costly search for a NET may be justified. Considering the various forms of polyglandular syndrome, this may represent a variant and we here provide an algorithm for working up such patients, while also reviewing literature on the intertwined relationship between the immune and endocrine systems.

Dermatologic manifestations of endocrine disorders

PURPOSE OF REVIEW

The diagnosis of many childhood endocrine disorders can be facilitated by an awareness of the associated dermatologic findings. In this review, we will survey examples of endocrine disorders in children that include a prominent or diagnostic dermatologic sign/symptom.

RECENT FINDINGS

A key concept is that skin findings often accompany hormonal conditions, both those of hormone excess and hormone deficiency/resistance. Some dermatologic signs may also represent the hallmark lesion, or provide the first clinical sign in childhood, for both familial tumoral and nontumoral syndromes. Moreover, skin as an endocrine organ itself may provide new avenues both to understand disease mechanisms as well as to provide targeted therapy.

SUMMARY

Early diagnosis, often aided by recognition of a keynote dermatologic lesion, may permit prompt, timely treatment that, in some cases, may even prove life saving. Conversely, when these associated signs go undetected or misdiagnosed, therapeutic intervention may be delayed unnecessarily.

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.

The putative role of endoplasmic reticulum aminopeptidases in autoimmunity: insights from genomic-wide association studies

Autoimmune diseases represent a heterogeneous group of conditions whose incidence is increasing worldwide. This has stimulated studies on their etiopathogenesis, derived from a complex interaction between genetic and environmental factors, aimed at finally improving prevention and treatment of these diseases. In the autoimmune process, immune responses are generated against self antigens presented by Major Histocompatibility Complex (MHC) class I on the cell surface. These peptide/MHC class I complexes are generated and assembled through MHC class I antigen processing and presentation machinery. In the endoplasmic reticulum (ER), aminopeptidases ERAP1 and ERAP2 display distinct trimming activity before antigenic peptides are loaded onto MHC class I molecules. The advent of new tools such as genome-wide association studies (GWAS) has provided evidence for new susceptibility loci and candidate genes playing a role in the autoimmune process for the recognized immune function of their transcripts. Genetic linkage has been discovered with MHC antigens and various autoimmune conditions. Recent GWAS showed the importance of ERAP1 and ERAP2 in several autoimmune diseases, including ankylosing spondylitis, insulin-dependent diabetes mellitus, psoriasis, multiple sclerosis, Crohn's disease. In this review, we first provide a general overview of ERAP1 and ERAP2 genes, their biological functions and their relevancy in autoimmunity. We then discuss the importance of GWAS and the case-control studies that confirm the relevancy of ERAP single-nucleotide polymorphism associations and their linkage with particular MHC class I haplotypes, supporting a putative functional role in the autoimmune process.

[Polyglandular autoimmune syndromes]

Polyglandular autoimmune syndromes (PGA) are a heterogeneous group of diseases in which a genetically caused dysfunction of the immune system leads to a destruction of endocrine glands with subsequent loss of function. In addition non-endocrine autoimmune diseases are also frequently present. Due to different patterns of inheritance and occurrence of disease a differentiation is made between juvenile PGA (also called APECED, autoimmune polyendocrinopathy candidiasis ectodermal dystrophy) with a monogenetic alteration of the AIRE (autoimmune regulator) gene, different ethnic distribution and a typical triad of diseases and the adult form, mainly conditioned by mutations of the HLA (human leukocyte antigens) alleles on chromosome 6. The article will briefly deal with the very rare IPEX (immune dysfunction, polyendocrinopathy, enteropathy, x-linked) syndrome, where the FOXP3 gene on chromosome X is altered. Important for the diagnosis are the clinical appearance and functional tests of the endocrine glands and the testing for antibodies. Additionally for PGA I and IPEX genetic testing is advisable. Currently patient-adjusted hormone replacement therapy is very important and screening of family members is recommended.