Assessment of enamel hypoplasia in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED)

Autoimmune amelogenesis imperfecta in patients with APS-1 and coeliac disease

Ameloblasts are specialized epithelial cells in the jaw that have an indispensable role in tooth enamel formation-amelogenesis1. Amelogenesis depends on multiple ameloblast-derived proteins that function as a scaffold for hydroxyapatite crystals. The loss of function of ameloblast-derived proteins results in a group of rare congenital disorders called amelogenesis imperfecta2. Defects in enamel formation are also found in patients with autoimmune polyglandular syndrome type-1 (APS-1), caused by AIRE deficiency3,4, and in patients diagnosed with coeliac disease5-7. However, the underlying mechanisms remain unclear. Here we show that the vast majority of patients with APS-1 and coeliac disease develop autoantibodies (mostly of the IgA isotype) against ameloblast-specific proteins, the expression of which is induced by AIRE in the thymus. This in turn results in a breakdown of central tolerance, and subsequent generation of corresponding autoantibodies that interfere with enamel formation. However, in coeliac disease, the generation of such autoantibodies seems to be driven by a breakdown of peripheral tolerance to intestinal antigens that are also expressed in enamel tissue. Both conditions are examples of a previously unidentified type of IgA-dependent autoimmune disorder that we collectively name autoimmune amelogenesis imperfecta.

A Rare Case of Autoimmune Polyendocrinopathy-candidiasis-ectodermal Dystrophy Syndrome: Dental Perspective on Diagnosis and Management

Aim

To report a unique case of Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) in a young boy and discuss the oral health impact and management of the disease.

Background

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autoimmune disorder with various clinical manifestations. Biallelic mutations in the autoimmune regulator (AIRE) gene lead to impairment of central immune tolerance and a targeted attack on various endocrine and non-endocrine organs. Patients classically suffer from a triad of disorders, including chronic mucocutaneous candidiasis (CMC), hypoparathyroidism, and adrenocortical failure (Addison's disease).

Results

In recent times, it has been observed that oral manifestations of the disorder, such as enamel hypoplasia, appear early and frequently. Affected individuals require a comprehensive preventive and minimally invasive approach for oral health along with follow-up throughout their lifespan to manage potentially life-threatening disease manifestations.

Conclusion

Prompt recognition by a pediatric dentist can facilitate an earlier diagnosis and allow for screening, preventive and therapeutic services.

Clinical Significance

To deliver oral health care in an effective and comprehensive manner, clinicians should be able to recognize, diagnose and manage the signs and symptoms of the disease.

How to cite this article

Tyagi R, Kalra N, Khatri A, et al. A Rare Case of Autoimmune Polyendocrinopathy-candidiasis-ectodermal Dystrophy Syndrome: Dental Perspective on Diagnosis and Management. Int J Clin Pediatr Dent 2023;16(1):139-146.

The Impacts of Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dysplasia (APECED) on the Oral Health of Children and Young People: A Review and Case Report

Aim:

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare, highly variable disease with significant oral health impacts. The aim of the study is to examine the existing evidence base surrounding the oral health impacts of APECED and consider the wider clinical significance of the condition relevant to the provision of pediatric dental care.

Materials and Methods:

The evidence surrounding APECED and the oral health impacts obtained from a review of multiple databases was qualitatively summarized in the form of a literature review. A case study was used to illustrate the relevance of literature in caring patients with APECED.

Results:

The literature describes a broad range of impacts from APECED, although it is characterized by chronic candidal infection, autoimmune hypoparathyroidism, and Addison’s disease. Oral manifestations of APECED appear frequently and can present early. Developmental defects of the teeth affect a large proportion of patients with APECED and together with candidiasis, characterize the key oral manifestations of the disease. An enhanced preventive and minimally invasive approach to oral health care is recommended for these patients in light of the complexities of their medical condition.

Conclusion:

Patients with APECED require careful multidisciplinary care to ensure that the optimal oral health outcomes are achieved.

Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome type-1 (APS-1), is a rare monogenic autoimmune disease caused by loss-of-function mutations in the autoimmune regulator (AIRE) gene. AIRE deficiency impairs immune tolerance in the thymus and results in the peripheral escape of self-reactive T lymphocytes and the generation of several cytokine- and tissue antigen-targeted autoantibodies. APECED features a classic triad of characteristic clinical manifestations consisting of chronic mucocutaneous candidiasis (CMC), hypoparathyroidism, and primary adrenal insufficiency (Addison's disease). In addition, APECED patients develop several non-endocrine autoimmune manifestations with variable frequencies, whose recognition by pediatricians should facilitate an earlier diagnosis and allow for the prompt implementation of targeted screening, preventive, and therapeutic strategies. This review summarizes our current understanding of the genetic, immunological, clinical, diagnostic, and treatment features of APECED.

Profiling Autoantibodies against Salivary Proteins in Sicca Conditions

Salivary gland dysfunction occurs in several autoimmune and immune-related conditions, including Sjögren syndrome (SS); immune checkpoint inhibitor-induced sicca (ICIS) that develops in some cancer patients and is characterized by severe, sudden-onset dry mouth; and autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Although subjects with these conditions present with oral dryness and often exhibit inflammatory infiltration of the salivary gland, little is known about the B-cell humoral responses directed against salivary gland protein targets. In this study, autoantibodies were evaluated against Ro52, Ro60, and La, as well as against a panel of 22 proteins derived from the salivary proteome. The tested cohort included healthy volunteers and subjects with SS, ICIS, and APECED without and with sicca. As expected, a high percentage of autoantibody seropositivity was detected against Ro52, Ro60, and La in SS, but only a few ICIS patients were seropositive for these autoantigens. A few APECED subjects also harbored autoantibodies to Ro52 and La, but only Ro60 autoantibodies were weakly associated with a small subset of APECED patients with sicca. Additional testing of the salivary panel failed to detect seropositive autoantibodies against any of the salivary-enriched proteins in the SS and ICIS subjects. However, APECED subjects selectively demonstrated seropositivity against BPI fold containing family A member 1 (BPIFA1), BPI fold containing family A member 2 (BPIFA2)/parotid salivary protein (PSP), and lactoperoxidase, 3 salivary-enriched proteins. Moreover, high levels of serum autoantibodies against BPIFA1 and BPIFA2/PSP occurred in 30% and 67% of the APECED patients with sicca symptoms, respectively, and were associated with an earlier age onset of oral dryness (P = 0.001). These findings highlight the complexity of humoral responses in different sicca diseases and provide new insights and biomarkers for APECED-associated sicca (ClinicalTrials.gov: NCT00001196; NCT00001390; NCT01425892; NCT01386437).

Dental Findings in Patients With Non-surgical Hypoparathyroidism and Pseudohypoparathyroidism: A Systematic Review

Background: Dental aberrations have been mentioned in relation to non-surgical hypoparathyroidism (Ns-HypoPT) and pseudohypoparathyroidism (PHP). However, a systematic review of dental characteristics have not been performed. The present systematic review describes the dental findings in patients with Ns-HypoPT and PHP.

Methods: Studies on Ns-HypoPT and PHP reporting dental features were eligible. A systematic literature search was conducted using four bibliographic databases (Web of Science, Scopus, Pubmed, and Embase) and was limited to studies written in English. Reviews, meta-analyses and letters were excluded. Both the research and reporting of results were based on PRISMA (preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines.

Results: Of 88 studies included, nine were cross-sectional, one was a prospective cohort study, 26 were case series, and 52 were case reports. The most frequently reported findings in patients with Ns-HypoPT were enamel opacities, enamel hypoplasia, hypodontia, and eruption disturbances. In patients with PHP, enamel hypoplasia, eruption disturbance, and deviation of the root morphology were the most frequently reported findings.

Conclusion: An association between enamel hypoplasia and Ns-HypoPT and PHP is likely. The results should, however, be interpreted cautiously due to the limited number of high-quality studies. The present review confirms the need of further well-designed studies, such as large-scale studies, e.g., multicenter studies, to conclude on the reported associations between Ns-HypoPT/PHP and enamel hypoplasia.

[Oral diseases in auto-immune polyendocrine syndrome type 1]

Auto-immune polyendocrine syndrome type 1 (APS1) also called Auto-immune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED) is a rare monogenic childhood-onset auto-immune disease. This autosomal recessive disorder is caused by mutations in the auto-immune regulator (AIRE) gene, and leads to autoimmunity targeting peripheral tissues. There is a wide variability in clinical phenotypes in patients with APSI, with auto-immune endocrine and non-endocrine disorders, and chronic mucocutaneous candidiasis. These patients suffer from oral diseases such as dental enamel hypoplasia and candidiasis. Both are frequently described, and in recent series, enamel hypoplasia and candidiasis are even the most frequent components of APS1 together with hypoparathyroidism. Both often occur during childhood (before 5 years old for canrdidiasis, and before 15 years old for enamel hypoplasia). Oral candidiasis is recurrent all life long, could become resistant to azole antifungal after years of treatment, and be carcinogenic, leading to severe oral squamous cell carcinoma. Oral components of APS1 should be diagnosed and rigorously treated. Dental enamel hypoplasia and/or recurrent oral candidiasis in association with auto-immune diseases in a young child should prompt APS1 diagnosis.

[One case of type 1 auto-immune polyendocrinopathy or APECED]

INTRODUCTION

autoimmune polyendocrinopathy with candidiasis and ectodermal dystrophy (APECED) is a rare autosomal recessive disorder caused by mutations in the autoimmune regulator gene (AIRE). We report the case of a young girl with APECED.

CASE REPORT

an 18 year-old girl born to consanguineous parents consulted for diffuse alopecia. Dermatological examination showed nail and dental enamel dystrophy and angular cheilitis. She had a history of mineralocorticoid deficiency (Addison's disease), hypoparathyroidism, hypogonadism and Biermer's disease, and she had also had chronic mucocutaneous candidiasis since childhood. She was presenting APECED with autoimmune endocrine failure, chronic mucocutaneous candidiasis and abnormalities of ectoderm-derived tissue. Analysis of mutation in the AIRE gene showed the c.769C>T homozygous mutation in exon 6.

DISCUSSION

APECED, a rare autosomal recessive disorder, is a potentially life-threatening autoimmune disease. Chronic mucocutaneous candidiasis is a common and early feature in children. Dermatologists are likely to be the first physicians to diagnose this syndrome.

Clinical and microstructural aberrations of enamel of deciduous and permanent teeth in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy

OBJECTIVE

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) causes multiple endocrine deficiencies, oral candidiasis and different forms of ectodermal dystrophy including enamel hypoplasia, documented in permanent teeth. Our purpose was to examine dental aberrations associated with APECED, including possible manifestations in primary teeth.

DESIGN

We studied clinically, radiographically, and by scanning electron microscopy (SEM) teeth of children belonging to two APECED families with different mutations in the AIRE gene.

RESULTS

In addition to enamel defects in the permanent teeth we observed hypoplastic pits and hypomaturated patches in the deciduous teeth with underlying changes in the prismatic ultrastructure. The enamel of the permanent molars exhibited a layered arrangement with included whirl-like formations.

CONCLUSIONS

Our findings confirm that APECED causes enamel defects that are individually but chronologically distributed, and can alter enamel development early enough to affect deciduous teeth.

Oral health in Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED)

BACKGROUND

APECED (Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy) is a rare autosomal recessive disease characterised primarily by sequential immune-mediated destruction of endocrine tissues, chronic oral or mucocutaneous candidiasis and ectodermal disorders, including hypoplasia of dental enamel.

AIM

This was to investigate the oral health and presence of enamel defects in a cohort of patients with APECED.

METHODS

16 patients with APECED (mean age of 13.9 years) were matched for age and gender with healthy controls. A comprehensive medical, dental and drug history was recorded, followed by a clinical assessment of oral health which was determined by assessing periodontal treatment needs, prevalence of dental caries, erosion, fluorosis and enamel defects. The estimated time of the development of the enamel defects and the contemporaneous medical diagnosis were recorded.

RESULTS

Oral health of patients with APECED was poor compared with controls, with a higher prevalence of periodontal disease, caries and erosion. There was a significantly (P < 0.05) higher prevalence of enamel defects in the study group. The enamel defects were mostly hypoplastic in the form of pits, missing enamel and grooves. The enamel defects occurred in a chronological pattern. There was a strong association between the estimated time of defective enamel formation and a history of hypoparathyroidism. Gastrointestinal dysfunction and a history of chronic mucocutaneous candidiasis were also associated with the presence of enamel defects.

CONCLUSION

The oral health of individuals with APECED was poor compared with controls with a higher prevalence of periodontal disease, caries, erosion and enamel defects. The enamel defects in the study population occurred in a chronological pattern and some were associated with a history of systemic disease during the period of tooth development.

Clinical and microstructural aberrations of enamel of deciduous and permanent teeth in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy

OBJECTIVE

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) causes multiple endocrine deficiencies, oral candidiasis and different forms of ectodermal dystrophy including enamel hypoplasia, documented in permanent teeth. Our purpose was to examine dental aberrations associated with APECED, including possible manifestations in primary teeth.

DESIGN

We studied clinically, radiographically, and by scanning electron microscopy (SEM) teeth of children belonging to two APECED families with different mutations in the AIRE gene.

RESULTS

In addition to enamel defects in the permanent teeth we observed hypoplastic pits and hypomaturated patches in the deciduous teeth with underlying changes in the prismatic ultrastructure. The enamel of the permanent molars exhibited a layered arrangement with included whirl-like formations.

CONCLUSIONS

Our findings confirm that APECED causes enamel defects that are individually but chronologically distributed, and can alter enamel development early enough to affect deciduous teeth.

Clinical manifestations and management of patients with autoimmune polyendocrine syndrome type I

Autoimmune polyendocrine syndrome type I (APS-I) is a monogenic model disease of autoimmunity. Its hallmarks are chronic mucocutaneous candidosis, hypoparathyroidism and adrenal insufficiency, but many other autoimmune disease components occur less frequently. The first components usually appear in childhood, but may be delayed to adolescence or early adult life. There is enormous variation in presentation and phenotype, which makes the diagnosis difficult. Antibodies against interferon-omega and -alpha have recently been shown to be sensitive and relatively specific markers for APS-I, and mutational analysis of the autoimmune regulator gene gives the diagnosis in >95% of cases. The treatment and follow-up of patients is demanding and requires the collaboration of specialists of several fields. However, the literature is especially sparse regarding information on treatment and follow-up; hence, we present here a comprehensive overview on clinical characteristics, treatment and follow-up based on personal experience and published studies.

The genetic basis of inherited anomalies of the teeth. Part 2: syndromes with significant dental involvement

Teeth are specialized structural components of the craniofacial skeleton. Developmental defects occur either alone or in combination with other birth defects. In this paper, we review the dental anomalies in several multiple congenital anomaly (MCA) syndromes, in which the dental component is pivotal in the recognition of the phenotype and/or the molecular basis of the disorder is known. We will consider successively syndromic forms of amelogenesis imperfecta or enamel defects, dentinogenesis imperfecta (i.e. osteogenesis imperfecta) and other dentine anomalies. Focusing on dental aspects, we will review a selection of MCA syndromes associated with teeth number and/or shape anomalies. A better knowledge of the dental phenotype may contribute to an earlier diagnosis of some MCA syndromes involving teeth anomalies. They may serve as a diagnostic indicator or help confirm a syndrome diagnosis.

Dermatological manifestations of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome

BACKGROUND

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED; OMIM 240300) is a rare autosomal recessive disorder defined by a variable combination of endocrine failure, chronic mucocutaneous candidiasis (CMC), and dystrophy of the dental enamel and nails. APECED is caused by mutations in the autoimmune regulator gene (AIRE). Alopecia areata (AA) and vitiligo are diseases with autoimmune pathogeneses, and have been recognized as part of the APECED complex. There are rare reports of other cutaneous manifestations.

OBJECTIVES

We sought to delineate the dermatological features of APECED in an Irish case series with emphasis on timing of their appearance and association with disease severity. Furthermore, we looked for evidence of genotype: phenotype correlation. Finally, we wanted to determine if the ectodermal changes described represent a primary ectodermal dysplasia or whether the ectodermal manifestations are secondary phenomena.

METHODS

Irish patients with APECED were invited to attend a multidisciplinary clinic (Dermatology, Endocrinology, Dentistry and Ophthalmology) held in Our Lady's Hospital for Sick Children, Dublin. Clinical data were compiled from case notes and questionnaires. All patients had a detailed cutaneous examination. Blood samples were obtained for mutational analysis.

RESULTS

Eighteen patients (seven males and 11 females) from 15 families were interviewed and examined. The mean age at diagnosis was 6 years (range 8 months-18 years). All patients had evidence of CMC, 13 (72%) had candidal onychomycosis or paronychia, six (33%) had AA and two had vitiligo. In the case of two patients the diagnosis was made on recognition of dermatological manifestations and confirmed by mutational analysis. Both patients developed Addison's disease on follow-up. CMC was an early feature, often predating diagnosis (10 of 18). AA and vitiligo presented later, and may reflect more severe disease in these cases. There was no correlation between the AIRE mutations identified on mutational analysis and the clinical presentation. We found no evidence of an isolated nail dystrophy or features consistent with a primary ectodermal dysplasia.

CONCLUSIONS

APECED is a rare but complex and potentially life-threatening autoimmune disease. CMC is a common and early feature; diagnosis at this stage may pre-empt life-threatening endocrinological crises. It is important for dermatologists to be aware of this association as they are likely to be the earliest clinicians who encounter these children. AA and vitiligo in our series occurred in the setting of established disease. The term "ectodermal dystrophy" is misleading as the ectodermal features described in our series and in the literature are most likely to be secondary phenomena.

Autoimmune adrenal insufficiency and autoimmune polyendocrine syndromes: autoantibodies, autoantigens, and their applicability in diagnosis and disease prediction

Recent progress in the understanding of autoimmune adrenal disease, including a detailed analysis of a group of patients with Addison's disease (AD), has been reviewed. Criteria for defining an autoimmune disease and the main features of autoimmune AD (history, prevalence, etiology, histopathology, clinical and laboratory findings, cell-mediated andhumoral immunity, autoantigens and their autoepitopes, genetics, animal models, associated autoimmune diseases, pathogenesis, natural history, therapy) have been described. Furthermore, the autoimmune polyglandular syndromes (APS) associated with AD (revised classification, animal models, genetics, natural history) have been discussed. Of Italian patients with primary AD (n = 317), 83% had autoimmune AD. At the onset, all patients with autoimmune AD (100%) had detectable adrenal cortex and/or steroid 21-hydroxylase autoantibodies. In the course of natural history of autoimmune AD, the presence of adrenal cortex and/or steroid 21-hydroxylase autoantibodies identified patients at risk to develop AD. Different risks of progression to clinical AD were found in children and adults, and three stages of subclinical hypoadrenalism have been defined. Normal or atrophic adrenal glands have been demonstrated by imaging in patients with clinical or subclinical AD. Autoimmune AD presented in four forms: as APS type 1 (13% of the patients), APS type 2 (41%), APS type 4 (5%), and isolated AD (41%). There were differences in genetics, age at onset, prevalence of adrenal cortex/21-hydroxylase autoantibodies, and associated autoimmune diseases in these groups. "Incomplete" forms of APS have been identified demonstrating that APS are more prevalent than previously reported. A varied prevalence of hypergonadotropic hypogonadism in patients with AD and value of steroid-producing cells autoantibodies reactive with steroid 17alpha-hydroxylase or P450 side-chain cleavage enzyme as markers of this disease has been discussed. In addition, the prevalence, characteristic autoantigens, and autoantibodies of minor autoimmune diseases associated with AD have been described. Imaging of adrenal glands, genetic tests, and biochemical analysis have been shown to contribute to early and correct diagnosis of primary non-autoimmune AD in the cases of hypoadrenalism with undetectable adrenal autoantibodies. An original flow chart for the diagnosis of AD has been proposed.