Epidemiological and clinical aspects of autoimmune thyroid diseases in children with Down's syndrome

JAK inhibition decreases the autoimmune burden in Down syndrome

Individuals with Down syndrome (DS), the genetic condition caused by trisomy 21 (T21), display clear signs of immune dysregulation, including high rates of autoimmune disorders and severe complications from infections. Although it is well established that T21 causes increased interferon responses and JAK/STAT signaling, elevated autoantibodies, global immune remodeling, and hypercytokinemia, the interplay between these processes, the clinical manifestations of DS, and potential therapeutic interventions remain ill defined. Here, we report a comprehensive analysis of immune dysregulation at the clinical, cellular, and molecular level in hundreds of individuals with DS. We demonstrate multi-organ autoimmunity of pediatric onset concurrent with unexpected autoantibody-phenotype associations. Importantly, constitutive immune remodeling and hypercytokinemia occur from an early age prior to autoimmune diagnoses or autoantibody production. We then report the interim analysis of a Phase II clinical trial investigating the safety and efficacy of the JAK inhibitor tofacitinib through multiple clinical and molecular endpoints. Analysis of the first 10 participants to complete the 16-week study shows a good safety profile and no serious adverse events. Treatment reduced skin pathology in alopecia areata, psoriasis, and atopic dermatitis, while decreasing interferon scores, cytokine scores, and levels of pathogenic autoantibodies without overt immune suppression. Additional research is needed to define the effects of JAK inhibition on the broader developmental and clinical hallmarks of DS. ClinicalTrials.gov identifier: NCT04246372.

Graves' disease in children with Down syndrome

While subclinical or overt hypothyroidism are common in Down syndrome (DS); Graves' disease (GD) is rare (ranges 0.6-3%). We aimed to evaluate the clinical features, course, and treatment of GD in children with DS and compare them with those without DS. Among 161 children with GD, 13 (8 female, 5 male) had DS (8%). Data were collected retrospectively from patients' medical records. The mean age at diagnosis was 10.6 ± 4.5 years, with a female-to-male ratio 1.6:1. The main symptoms were weight loss (n = 6), increased irritability (n = 3), and increased sweating (n = 3). None had orbitopathy. Seven of 11 patients with a thyroid ultrasound at diagnosis had a goitre. On admission, all had thyroid-stimulating hormone (TSH) <0.01 mU/L (normal range (NR): 0.51-4.30), free triiodothyronine, free thyroxine (mean ± s.d .), and thyrotrophin receptor antibodies (median, range) were 22.2 ± 10.2 pmol/L (NR: 3.5-8.1), 50.2 ± 18.7 pmol/L (NR 12.6-20.9), and 17.0 (2.89-159.0) U/L (NR <1), respectively. Patients were treated either with methimazole (n = 10) or carbimazole (n = 3), a dose of 0.54 ± 0.36 mg/kg/day. The treatment was 'block and replace' in ten patients and 'dose titration' in three patients, with a mean duration of 43.4 ± 11.0 months. Of 13 patients, four are still receiving primary treatment, three are in remission, one patient had two medically treated recurrences, three underwent surgery without complications, and two patients were lost to follow-up. Our data show that the clinical course of GD in patients with DS was similar to those without DS and suggest that a prolonged medical therapy should be the preferred option.

Cardiac Pre-tamponade Secondary to Generalized Myxedema Due to Neglected Hashimoto's Thyroiditis in a Child With Down Syndrome

Down syndrome (DS) is the most common chromosomal disorder in live-born infants, often associated with intellectual disability and various medical conditions, including thyroid dysfunction. Hashimoto's thyroiditis (HT), an autoimmune subtype, is a leading cause of acquired hypothyroidism in DS children. Severe hypothyroidism can precipitate myxedema, a critical condition linked to complications like pericardial effusion and cardiac tamponade. This case study presents a nine-year-old male with DS who was admitted for acute respiratory distress exhibiting classic signs of myxedema. Initial investigations revealed severe hypothyroidism and significant pericardial effusion. Surgical pericardiotomy drained 800 mL of fluid, confirming myxedema secondary to HT. Levothyroxine therapy led to progressive improvement, resolving myxedematous infiltrate and associated symptoms within a month. Follow-up at 12 months demonstrated sustained improvement with normalized thyroid function and no clinical disease activity. This case highlights an atypical presentation of HT in a DS child with cardiac pre-tamponade.

The innate immune system stimulating cytokine GM-CSF improves learning/memory and interneuron and astrocyte brain pathology in Dp16 Down syndrome mice and improves learning/memory in wild-type mice

Down syndrome (DS) is characterized by chronic neuroinflammation, peripheral inflammation, astrogliosis, imbalanced excitatory/inhibitory neuronal function, and cognitive deficits in both humans and mouse models. Suppression of inflammation has been proposed as a therapeutic approach to treating DS co-morbidities, including intellectual disability (DS/ID). Conversely, we discovered previously that treatment with the innate immune system stimulating cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF), which has both pro- and anti-inflammatory activities, improved cognition and reduced brain pathology in a mouse model of Alzheimer's disease (AD), another inflammatory disorder, and improved cognition and reduced biomarkers of brain pathology in a phase II trial of humans with mild-to-moderate AD. To investigate the effects of GM-CSF treatment on DS/ID in the absence of AD, we assessed behavior and brain pathology in 12-14 month-old DS mice (Dp[16]1Yey) and their wild-type (WT) littermates, neither of which develop amyloid, and found that subcutaneous GM-CSF treatment (5 μg/day, five days/week, for five weeks) improved performance in the radial arm water maze in both Dp16 and WT mice compared to placebo. Dp16 mice also showed abnormal astrocyte morphology, increased percent area of GFAP staining in the hippocampus, clustering of astrocytes in the hippocampus, and reduced numbers of calretinin-positive interneurons in the entorhinal cortex and subiculum, and all of these brain pathologies were improved by GM-CSF treatment. These findings suggest that stimulating and/or modulating inflammation and the innate immune system with GM-CSF treatment may enhance cognition in both people with DS/ID and in the typical aging population.

Vitiligo and chronic autoimmune thyroiditis

Vitiligo, the discoloration of the skin, has different autoimmune mechanisms reflected by many biomarkers as shown by skin histology, staining for CD4 and CD8 T lymphocytes, chemokine ligand 9 or circulating cytokines such as interleukin (IL)-1 beta, interferon (IFN)-gamma, transforming growth factor (TGF)-beta, antibodies, markers of oxidative stress, chemokines, and others. In this narrative review, we aim to overview vitiligo in relationship with chronic autoimmune thyroiditis. Regarding vitiligo, more than 50 different genetic loci have been associated with this disease, and the heritability is high. There is a 20% risk of an environmental connection which may also act as a trigger; moreover, the association with human leukocyte antigen (HLA) expression is well recognized. The specific lesions display CD8+ tissue-resident memory T cells as continuous key activators of melanocytes. The association with chronic thyroiditis is based on common autoimmune background and excessive reactive oxygen species that destroy melanocytes and thyrocytes (oxidative stress hypothesis) with thyroxine and melanin as target molecules, thus sharing a common origin: tyrosine. Moreover, common epigenetic anomalies or mutations of the Forkhead transcription factor D3 (FOXD3) have been described. Since vitiligo affects up to 1–2% of the population worldwide and 34% of patients have positive thyroid antibodies, apart from common autoimmunity background and oxidative stress toxicity, the association is clinically relevant for different practitioners.

Autoimmunity and Genetic Syndromes: A Focus on Down Syndrome

Within immune system-related diseases, autoimmunity has always represented a field of great interest, although many aspects remain poorly understood even today. Genetic syndromes associated with immunity disorders are common and represent an interesting model for a better understanding of the underlying mechanism of autoimmunity predisposition. Among these conditions, Down syndrome (DS) certainly deserves special attention as it represents the most common genetic syndrome associated with immune dysregulation, involving both innate and adaptive immunity. Autoimmunity represents a well-known complication of DS: it is estimated that people affected by this disease present a risk four to six times higher than the normal population to develop autoimmune diseases such as celiac disease, type 1 diabetes mellitus, and hypo- or hyperthyroidism. Several factors have been considered as possible etiology, including genetic and epigenetic modifications and immune dysregulation. In times in which the life expectancy of people with DS has been extremely prolonged, thanks to improvements in the diagnosis and treatment of congenital heart disease and infectious complications, knowledge of the mechanisms and proper management of autoimmune diseases within this syndrome has become essential. In this short review, we aim to report the current literature regarding the genetic, immune, and environmental factors that have been proposed as the possible underlying mechanism of autoimmunity in individuals with DS, with the intent to provide insight for a comprehensive understanding of these diseases in genetic syndromes.

Basedow-Graves' disease in a pediatric patient with Sticlker syndrome, a new endocrine finding to improve personalized treatment

Background

Stickler syndrome is a connective tissue disorder with predominantly autosomal dominant inheritance, with ocular, auditory and joint involvement.

Thyroid dysfunction was not described as part of alterations in Stickler syndrome and in particular, the association between Stickler’s syndrome and Graves’ disease has never been previously reported in literature.

Moreover, the presence of Graves’ disease is uncommon in the pediatric age (especially in children younger than 6 years old).

Case presentation

We report the case of a 5-years old child affected by Stickler syndrome who received the diagnosis of Graves’s disease, in absence of suggestive symptoms, during health supervision.

Conclusions

This is the first evidence of thyroid dysfunction and autoimmune pattern for Sticker syndrome.

Further clinical reports are expected before suggesting the implementation of new clinical skills for Stickler syndrome, but this paper may contribute to improve personalized management of this rare disorder.

Timing, prevalence, and dynamics of thyroid disorders in children and adolescents affected with Down syndrome

Objectives Limited data on the evolution of thyroid disorders (TD) in Down syndrome (DS) are available. We characterized the timing, prevalence, and dynamics of TD in patients with DS during a long-term follow-up. Methods We retrospectively evaluated 91 children and adolescents with DS (12.5 ± 8.3; follow-up 7.5 ± 6.2). Children were monitored at birth, 6, and 12 months of age and twice a year thereafter. Thyroid status and autoimmunity were periodically investigated. Results TD were detected in 73.6% of patients, in particular congenital hypothyroidism (CH), autoimmune thyroid diseases (ATD) and subclinical hypothyroidism (SH) were recorded in 16.4, 31.8, and 25.3%, respectively. CH was diagnosed at newborn screening in 86.7% of cases and in the first 6 months of life in the remaining 13.3%; the condition was persistent in 61.5% of patients. In more than 30% of CH cases, glandular hypoplasia was also revealed. In the ATD group, 63.1% of patients with Hashimoto's disease (HD, 82.6%) were treated with levothyroxine and subjects with Graves' Disease (GD, 17.4%) started therapy with methimazole. DS with SH were treated in 42.1% of cases. A thyroid hypogenic echopattern, without autoantibody positivity was identified in 27.6% of SH patients. Conclusions The high prevalence and evolution of TD in SD requires frequent monitoring starting in the first months of life. CH can be misdiagnosed at screening. In DS subjects, there is a high prevalence of ATD and non-autoimmune diseases with early antibody-negative phases should not be excluded.

Autoimmune Thyroid Disease in Specific Genetic Syndromes in Childhood and Adolescence

Autoimmune thyroid disease (ATD) is the most frequent cause of acquired thyroid dysfunction, most commonly presenting either as Hashimoto's thyroiditis or Graves' Disease. Hashimoto's thyroiditis is characterized by the presence of thyroid-specific autoantibodies, more commonly anti-thyroperoxidase antibodies in the serum and the typical inhomogeneous echostructure of the thyroid on a thyroid ultrasound examination. Hashimoto's thyroiditis can for a long time be accompanied by normal thyroid function and hypothyroidism can only progressively be established. Graves' disease is much less frequent in childhood and adolescence and presents with overt hyperthyroidism. After the onset of puberty, ATD affects females with a higher incidence than males, while during the prepubertal period there is not such a clear preponderance of affected females. ATD can occur either isolated or in the context of other autoimmune disorders, such as type 1 Diabetes mellitus (T1D), celiac disease, alopecia areata, vitiligo, etc. Especially at the pediatric age, a higher incidence of ATD is also observed in the context of specific genetic syndromes, such as trisomy 21 (Down syndrome), Klinefelter syndrome, Turner syndrome, or 22q11.2 deletion syndrome. Nevertheless, although thyroid dysfunction may also be observed in other genetic syndromes, such as Prader-Willi or Williams syndrome, the thyroid dysfunction in these syndromes is not the result of thyroid autoimmunity. Interestingly, there is emerging evidence supporting a possible link between autoimmunity and RASopathies. In this review article the incidence, as well as the clinical manifestation and accompanied pathologies of ATD in specific genetic syndromes will be presented and regular follow-up for the early identification of the disorder will be proposed.

Down syndrome with primary thyroid diffuse large B-cell lymphoma and Hashimoto thyroiditis: A CARE compliant case report

RATIONALE

Adult patients with Down syndrome (DS) commonly develop Hashimoto thyroiditis (HT). However, primary diffuse large B-cell lymphoma (DLBCL) of the thyroid is uncommon, and its simultaneous occurrence with HT is very rare. To our knowledge, coexisting DLBCL and HT in a patient with DS has not been reported in the medical literature.

PATIENT CONCERNS

We present a 43-year-old woman with DS who reported progressive swelling of the neck on the right side and dyspnea over the previous 1 month, with associated neck ache, hoarseness, and dysphagia. Thyroid ultrasonography and computed tomography of the neck revealed a large mass in the right lobe compressing the surrounding tissues.

DIAGNOSES

Based on the clinical and histopathologic findings, the patient was diagnosed with coexisting primary thyroid DLBCL and HT.

INTERVENTIONS

A palliative unilateral thyroidectomy was performed; postoperative histopathology and immunohistochemistry revealed thyroid DLBCL and HT. The patient was scheduled for chemotherapy and targeted therapy after recovering from surgery.

OUTCOMES

The patient died 3 weeks after surgery due to asphyxia caused by uncontrollable growth of recurrent tumor.

LESSONS

The coexistence of DS, primary thyroid DLBCL, and HT is very rare. There is no standardized approach to the clinical identification of primary thyroid lymphoma (PTL), making early diagnosis difficult. A multidisciplinary approach and close follow-up are needed. The mechanisms of the link between DS and PTL are poorly understood and remain to be elucidated.

Controversies in the pharmacological treatment of Graves' disease in children

INTRODUCTION

Graves' disease (GD) is a disorder, in which auto-immunity against the thyroid- stimulating hormone (TSH) receptor is the pivotal pathogenetic element. This disease may have different clinical manifestations, the most common being thyrotoxicosis. Treatment of this condition differs according to its etiology, but there is currently no evidence-based therapeutic strategy which is universally adopted in all countries. Areas covered: a systematic review of the updates on the management of pediatric GD was performed using the Pubmed data base until March 2018. Systematic reviews with or without meta-analysis were analyzed using the following terms: Antithyroid drugs, Childhood, Hyperthyroidism, Radioactive iodine, Thyroidectomy. Expert commentary: As the best way to manage children with GD remains a matter of debate among pediatric endocrinologists, and there is currently no evidence-based therapeutic strategy which is universally adopted, we confirm that the original and prolonged treatment with anti-thyroid drugs (ATDs) remains the mainstay of treatment for juvenile hyperthyroidism. Alternative treatments include radioiodine (RAI) therapy or surgery (total thyroidectomy). We recommend individualizing the therapeutic approach, without prejudices toward radical therapies that become necessary in case of relapse, adverse effects or poor compliance to ATDs. The optimal approach depends on patient or family preference, and specific patient clinical features.

Intensive Combination Immunotherapy and Neuroinflammation Resolution in a Child With Anti-PCA-1 (Yo) Paraneoplastic Syndrome and 2 Malignancies

Paraneoplastic cerebellar degeneration is rare and noteworthy in children. In this 7-year-old, it was documented to have occurred within a year of ataxia presentation. The instigating cancer was stage III adrenal adenocarcinoma, remitted after surgical resection at age 2. When her severe ataxia progressed, neuroinflammation was characterized by high cerebrospinal fluid Purkinje cell cytoplasmic antibody type 1 titers, oligoclonal bands, and neurofilament light chain. The immunotherapy strategy was to replace IV methylprednisolone, which lowered Purkinje cell cytoplasmic antibody type 1 titers without clinical improvement, with induction of adrenocorticotropic hormone/intravenous immunoglobulin/rituximab (ACTH/IVIG/rituximab) combination immunotherapy, ACTH/dexamethasone transition, and intravenous immunoglobulin maintenance. She became self-ambulatory and cerebrospinal fluid inflammatory markers regressed. Down syndrome predisposed her to a second cancer, pre-B acute lymphoblastic leukemia, 4 years later. Despite reversible cytosine arabinoside-provoked cerebellar toxicity, the ataxia is stable on monthly intravenous immunoglobulin without relapse, now 5 years after initial diagnosis. This report illustrates the use of cerebrospinal fluid biomarkers to detect, target, and monitor neuroinflammation, and successful combinations of immunotherapy to better the quality of life.