Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) in the Irish population

Cutaneous Manifestations in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED): A Comprehensive Review

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), or polyglandular autoimmune syndrome type 1 (PAS-1/APS-1), is a rare autosomal recessive disorder linked to mutations in the autoimmune regulator (AIRE) gene. This review provides a detailed analysis of cutaneous manifestations in APECED, focusing on chronic mucocutaneous candidiasis (CMC), alopecia areata (AA), and vitiligo. The classic triad of hypoparathyroidism, adrenal insufficiency, and CMC serves as a diagnostic cornerstone. However, the varied clinical spectrum of APECED, particularly its cutaneous presentations, poses a diagnostic challenge. CMC, often an early sign, varies in prevalence across populations, including Finnish (100%), Irish (100%), Saudi Arabian (80%), Italian (60-74.7%), North American (51-86%), and Croatian (57.1%) populations. Similarly, AA prevalence varies in different populations. Vitiligo also exhibits variable prevalence across regions. The review synthesizes the current knowledge arising from a narrative analysis of 14 significant human studies published in English up to October 2023. Moreover, this paper underscores the importance of early detection and monitoring, emphasizing cutaneous manifestations as key diagnostic indicators. Ongoing research and clinical vigilance are crucial for unraveling the complexities of this rare autoimmune syndrome and enhancing patient care.

Autoimmune polyendocrine syndrome type 1: Clinical manifestations, pathogenetic features, and management approach

Autoimmune polyendocrine syndrome type 1 (APS-1) is an autosomal recessive hereditary pathology that develops with endocrine and non-endocrine manifestations in childhood. The classic triad of APS-1 includes chronic candidiasis of the skin and mucous membranes, adrenal insufficiency, and hypoparathyroidism. APS-1 is often accompanied by hypogonadism, type 1 diabetes, autoimmune thyroiditis, vitiligo, alopecia, asplenia, pneumonitis, gastritis, pernicious anemia, and intestinal dysfunction, nephritis, and hepatitis. The prevalence rate is highest in genetically isolated populations (up to 1:6500-1:9000). APS-1 occurs because of mutations in the autoimmune regulator (AIRE) gene, leading to a disrupted mechanism of normal antigen expression, the formation of abnormal clones of immune cells, and autoimmune damage to various organs. Analysis of the AIRE gene is the main diagnostic method for early detection of APS-1 and the choice of methods for its treatment. Timely genetic counseling makes it possible to identify the disease early, prescribe appropriate treatment and prevent serious complications. This paper analyzes scientific information characterizing clinical manifestations of autoimmune polyendocrine syndrome type 1 in association with its pathogenetic features, epidemiology, and current management.

Clinical Characteristics in the Longitudinal Follow-Up of APECED Syndrome in Southern Croatia—Case Series

Background: Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare monogenetic autosomal recessive disorder caused by a mutation in the autoimmune regulator (AIRE) gene characterized by complex phenotypic characteristics discovered over years of follow-up. Methods: 7 patients were recruited in this case series in a period of the last 37 years from Southern Croatia. All patients were screened for AIRE R257X mutations. Results: This study group had a mean current age of 25.3 years (age range from 5.4 to 40.2 years), while the mean age at the onset of the disease was 6.5 years (age range from 0.7 to 9.2 years) and with a mean follow-up period of 17.8 years. The overall prevalence of APECED syndrome is estimated to be 1 in 75,000. The most common initial manifestation of the disease was onychodystrophy, while the first major component of APECED syndrome was chronic mucocutaneous candidiasis. Conclusions: APECED is a ‘‘multi-faced’’ disease based on the very unpredictable and inconsistent onset of major components. Furthermore, based on our results, we suggest that onychodystrophy could be included as a warning sign of APECED syndrome.

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.

French-Canadian families from Saguenay-Lac-Saint-Jean: a new founder population for APECED

PURPOSE

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is more prevalent in some founder populations, but relatively unexplored in Canada. This study aimed at investigating the French-Canadian patients through phenotypic and genotypic characterization.

METHOD

Phenotype and demographic characterization were done for 12 affected individuals belonging to eight unrelated families. Samples from 11 cases were analyzed in a molecular clinical laboratory, and muscle biopsies were reviewed for two individuals with a limb-girdle muscle dystrophy.

RESULTS

The clinical phenotype was similar to that observed in European Caucasian populations but differed in the non-endocrine spectrum from the American-reported series of cases. Two cases exhibited a limb-girdle muscle dystrophy, and we found preliminary evidence of a mitochondrial dysfunction, since all three biopsies examined showed COX-deficient fibers in excess of what would be expected for age. Electron microscopy showed mitochondrial accumulation without abnormal cristea or inclusions. The c.1616C > T variant in the AIRE gene was responsible for 100% of APECED cases in the French-Canadian population of Saguenay-Lac-Saint-Jean in Quebec, Canada.

CONCLUSIONS

We report the first series of French-Canadian cases affected with APECED. The Saguenay-Lac-Saint-Jean region was uncovered as a new founder population for this condition. Muscle biopsy findings expanded the range of previously described APECED-related myopathology. Long term follow-up of our genetically homogeneous French-Canadian cases may help determine if the c.1616C > T variant increases the risk of muscle involvement. A neonatal screening program is under consideration to prevent undesired life-threatening endocrine manifestations.

Autoimmune polyendocrine syndrome type 1: an Italian survey on 158 patients

BACKGROUND

Autoimmune Polyglandular Syndrome type 1 (APS-1) is a rare recessive inherited disease, caused by AutoImmune Regulator (AIRE) gene mutations and characterized by three major manifestations: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism (CH) and Addison's disease (AD).

METHODS

Autoimmune conditions and associated autoantibodies (Abs) were analyzed in 158 Italian patients (103 females and 55 males; F/M 1.9/1) at the onset and during a follow-up of 23.7 ± 15.1 years. AIRE mutations were determined.

RESULTS

The prevalence of APS-1 was 2.6 cases/million (range 0.5-17 in different regions). At the onset 93% of patients presented with one or more components of the classical triad and 7% with other components. At the end of follow-up, 86.1% had CH, 77.2% AD, 74.7% CMC, 49.5% premature menopause, 29.7% autoimmune intestinal dysfunction, 27.8% autoimmune thyroid diseases, 25.9% autoimmune gastritis/pernicious anemia, 25.3% ectodermal dystrophy, 24% alopecia, 21.5% autoimmune hepatitis, 17% vitiligo, 13.3% cholelithiasis, 5.7% connective diseases, 4.4% asplenia, 2.5% celiac disease and 13.9% cancer. Overall, 991 diseases (6.3 diseases/patient) were found. Interferon-ω Abs (IFNωAbs) were positive in 91.1% of patients. Overall mortality was 14.6%. The AIRE mutation R139X was found in 21.3% of tested alleles, R257X in 11.8%, W78R in 11.4%, C322fsX372 in 8.8%, T16M in 6.2%, R203X in 4%, and A21V in 2.9%. Less frequent mutations were present in 12.9%, very rare in 9.6% while no mutations in 11% of the cases.

CONCLUSIONS

In Italy, APS-1 is a rare disorder presenting with the three major manifestations and associated with different AIRE gene mutations. IFNωAbs are markers of APS-1 and other organ-specific autoantibodies are markers of clinical, subclinical or potential autoimmune conditions.

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.

APECED-Associated Hepatitis: Clinical, Biochemical, Histological and Treatment Data From a Large, Predominantly American Cohort

BACKGROUND AND AIMS

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), caused by autoimmune regulator (AIRE) mutations, manifests with chronic mucocutaneous candidiasis (CMC) and multisystem autoimmunity, most often hypoparathyroidism (HP) and adrenal insufficiency (AI). European cohorts previously reported a ~10% prevalence of APECED-associated hepatitis (APAH) with presentations ranging from asymptomatic laboratory derangements to fatal fulminant hepatic failure. Herein, we characterized APAH in a large APECED cohort from the Americas.

APPROACH AND RESULTS

Forty-five consecutive patients with APECED were evaluated (2013-2015) at the National Institutes of Health (NIH; NCT01386437). Hepatology consultation assessed hepatic and autoimmune biomarkers and liver ultrasound in all patients. Liver biopsies evaluated autoimmune features and fibrosis. The 16S ribosomal RNA (rRNA) sequencing was performed in 35 patients' stools (12 with and 23 without APAH). Among 43 evaluable patients, 18 (42%) had APAH; in 33.3% of those with APAH, APAH occurred before developing classic APECED diagnostic criteria. At APAH diagnosis, the median age was 7.8 years, and patients manifested with aminotransferase elevation and/or hyperbilirubinemia. All patients with APAH were in clinical remission during their NIH evaluation while receiving immunomodulatory treatment. We found no difference in age, sex, or prevalence of CMC, AI, or HP between patients with or without APAH. Autoantibody positivity against aromatic L-amino acid decarboxylase, cytochrome P450 family 1 subfamily A member 2, histidine decarboxylase (HDC), bactericidal/permeability-increasing fold-containing B1, tryptophan hydroxlase, and 21-hydroxylase (21-OH), and the homozygous c.967_979del13 AIRE mutation were associated with APAH development. Classical serological biomarkers of autoimmune hepatitis (AIH) were only sporadically positive. AIH-like lymphoplasmacytic inflammation with mild fibrosis was the predominant histological feature. Stool microbiome analysis found Slackia and Acidaminococcus in greater abundance in patients with APAH.

CONCLUSIONS

APAH is more common than previously described, may present early before classic APECED manifestations, and most often manifests with milder, treatment-responsive disease. Several APECED-associated autoantibodies, but not standard AIH-associated biomarkers, correlate with APAH.

Autoimmune Addison's Disease as Part of the Autoimmune Polyglandular Syndrome Type 1: Historical Overview and Current Evidence

The autoimmune polyglandular syndrome type 1 (APS1) is caused by pathogenic variants of the autoimmune regulator (AIRE) gene, located in the chromosomal region 21q22.3. The related protein, AIRE, enhances thymic self-representation and immune self-tolerance by localization to chromatin and anchorage to multimolecular complexes involved in the initiation and post-initiation events of tissue-specific antigen-encoding gene transcription. Once synthesized, the self-antigens are presented to, and cause deletion of, the self-reactive thymocyte clones. The clinical diagnosis of APS1 is based on the classic triad idiopathic hypoparathyroidism (HPT)—chronic mucocutaneous candidiasis—autoimmune Addison's disease (AAD), though new criteria based on early non-endocrine manifestations have been proposed. HPT is in most cases the first endocrine component of the syndrome; however, APS1-associated AAD has received the most accurate biochemical, clinical, and immunological characterization. Here is a comprehensive review of the studies on APS1-associated AAD from initial case reports to the most recent scientific findings.

An AIREless Breath: Pneumonitis Caused by Impaired Central Immune Tolerance

Autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a monogenic disorder caused by biallelic mutations in the AIRE gene, has historically been defined by the development of chronic mucocutaneous candidiasis together with autoimmune endocrinopathies, primarily hypoparathyroidism and adrenal insufficiency. Recent work has drawn attention to the development of life-threatening non-endocrine manifestations such as autoimmune pneumonitis, which has previously been poorly recognized and under-reported. In this review, we present the clinical, radiographic, autoantibody, and pulmonary function abnormalities associated with APECED pneumonitis, we highlight the cellular and molecular basis of the autoimmune attack in the AIRE-deficient lung, and we provide a diagnostic and a therapeutic roadmap for patients with APECED pneumonitis. Beyond APECED, we discuss the relevance and potential broader applicability of these findings to other interstitial lung diseases seen in secondary AIRE deficiency states such as thymoma and RAG deficiency or in common polygenic autoimmune disorders such as idiopathic Sjögren's syndrome.

Patients With APECED Have Increased Early Mortality Due to Endocrine Causes, Malignancies and infections

CONTEXT

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autoimmune endocrinopathy with severe and unpredictable course. The impact of APECED on mortality has not been determined.

OBJECTIVE

To assess overall and cause-specific mortality of patients with APECED.

DESIGN AND SETTING

A follow-up study of Finnish patients with APECED from 1971 to 2018. Causes and dates of death were collected from Finnish registries.

PATIENTS

Ninety-one patients with APECED.

MAIN OUTCOME MEASURE

Overall and cause-specific standardized mortality ratios (SMRs) determined by comparing the observed numbers of death and those expected on the basis of respective population death rates in Finland.

RESULTS

The overall disease mortality was significantly increased (29 deaths, SMR 11; 95% confidence interval [CI] 7.2-16; P < 0.001). The relative risk (SMR) was highest in the youngest age groups but the absolute excess risk was similar (about 10 per 10 000 person-years) in all age categories. The highest SMRs were seen for endocrine and metabolic diseases (SMR 570; 95% CI, 270-1000; P < 0.001) and for oral and esophageal malignancies (SMR 170; 95% CI, 68-360; P < 0.001). Mortality was also increased for infections, diseases of digestive system, alcohol-related deaths, and for accidents. Due to the small number of cases we were unable to evaluate whether mortality was affected by disease severity.

CONCLUSIONS

Patients with APECED have significantly increased mortality in all age groups. Highest SMRs are found for causes that are directly related to APECED but also for infections. Increased alcohol- and accident-related deaths may be influenced by psychosocial factors.

The study on the risk of other endocrine glands autoimmune diseases in patients with type 1 diabetes mellitus

To study the changes of pancreas, thyroid, adrenal, parathyroid and gonadal organ-specific antibodies in patients with type 1 diabetic patients and to explore the risk of development to other endocrine gland autoimmune diseases.Fifty one patients with type 1 diabetes mellitus were selected. ELISA was used to detect islet, adrenal gland, Parathyroid, gonadal organ-specific antibody levels, the level of thyroid-related antibodies by lectrochemiluminescence.Compared with the healthy control group, the levels of the 17-α-OHAb, 21-OHAb, NALP5Ab, P450sccAb, and CaSRAb in the T1DM group were significantly higher. GADAb-positive patients were more likely to have TPOAb-positive patients than GADAb-negative patients, and the positive rate of 2 thyroid antibodies in GADAb-positive patients was significantly higher than that in GADAb-negative patients. The presence of these antibodies is related to the age of onset of type 1 diabetes or Patient age. In combination with 1 or 2 islet antibody-positive patients, the combined non-islet antibody positive rate was higher than that of islet antibody-negative patients.Patients with type 1 diabetes with other autoimmune diseases at risk significantly increased compared with normal, of which the most common thyroid autoimmune disease, thyroid antibodies and hormone levels should be routinely detected at the first visit and long-term follow-up.

Lymphocyte-driven regional immunopathology in pneumonitis caused by impaired central immune tolerance

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a monogenic disorder caused by AIRE mutations, presents with several autoimmune diseases. Among these, endocrine organ failure is widely recognized, but the prevalence, immunopathogenesis, and treatment of non-endocrine manifestations such as pneumonitis remain poorly characterized. We enrolled 50 patients with APECED in a prospective observational study and comprehensively examined their clinical and radiographic findings, performed pulmonary function tests, and analyzed immunological characteristics in blood, bronchoalveolar lavage fluid, and endobronchial and lung biopsies. Pneumonitis was found in >40% of our patients, presented early in life, was misdiagnosed despite chronic respiratory symptoms and accompanying radiographic and pulmonary function abnormalities, and caused hypoxemic respiratory failure and death. Autoantibodies against BPIFB1 and KCNRG and the homozygous c.967_979del13 AIRE mutation are associated with pneumonitis development. APECED pneumonitis features compartmentalized immunopathology, with accumulation of activated neutrophils in the airways and lymphocytic infiltration in intraepithelial, submucosal, peribronchiolar, and interstitial areas. Beyond APECED, we extend these observations to lung disease seen in other conditions with secondary AIRE deficiency (thymoma and RAG deficiency). Aire-deficient mice had similar compartmentalized cellular immune responses in the airways and lung tissue, which was ameliorated by deficiency of T and B lymphocytes. Accordingly, T and B lymphocyte-directed immunomodulation controlled symptoms and radiographic abnormalities and improved pulmonary function in patients with APECED pneumonitis. Collectively, our findings unveil lung autoimmunity as a common, early, and unrecognized manifestation of APECED and provide insights into the immunopathogenesis and treatment of pulmonary autoimmunity associated with impaired central immune tolerance.

Lessons from primary immunodeficiencies: Autoimmune regulator and autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy

The discovery of the autoimmune regulator (AIRE) protein and the delineation of its critical contributions in the establishment of central immune tolerance has significantly expanded our understanding of the immunological mechanisms that protect from the development of autoimmune disease. The parallel identification and characterization of patient cohorts with the monogenic disorder autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), which is typically caused by biallelic AIRE mutations, has underscored the critical contribution of AIRE in fungal immune surveillance at mucosal surfaces and in prevention of multiorgan autoimmunity in humans. In this review, we synthesize the current clinical, genetic, molecular and immunological knowledge derived from basic studies in Aire-deficient animals and from APECED patient cohorts. We also outline major advances and research endeavors that show promise for informing improved diagnostic and therapeutic approaches for patients with APECED.

The heterogeneity of autoimmune polyendocrine syndrome type 1: Clinical features, new mutations and cytokine autoantibodies in a Brazilian cohort from tertiary care centers

Autoimmune polyendocrine syndrome type 1 (APS1) is characterized by multiorgan autoimmunity. We aim at characterizing a multi-center Brazilian cohort of APS1 patients by clinical evaluation, searching mutation in the AIRE gene, measuring serum autoantibodies, and investigating correlations between findings. We recruited patients based on the clinical criteria and tested them for AIRE mutations, antibodies against interferon type I and interleukins 17A, 17F and 22. We identified 12 unrelated families (13 patients) with typical signs of APS1 in the proband, and the screening of relatives recognized an asymptomatic child. Candidiasis was present in all cases, and 19 other manifestations were observed. All patients carried one of 10 different mutations in AIRE, being 3 new ones, and were positive for anti-interferon type I serum antibody. Anti-interleukin-17A levels inversely correlated with the number of manifestations in each patient. This negative correlation may suggest a protective effect of anti-interleukin-17A with a potential therapeutic application.

Chronic Mucocutaneous Candidiasis in Autoimmune Polyendocrine Syndrome Type 1

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is an autosomal recessive disease caused by mutations in the autoimmune regulator (AIRE) gene, characterized by the clinical triad of chronic mucocutaneous candidiasis (CMC), hypoparathyroidism, and adrenal insufficiency. CMC can be complicated by systemic candidiasis or oral squamous cell carcinoma (SCC), and may lead to death. The role of chronic Candida infection in the etiopathogenesis of oral SCC is unclear. Long-term use of fluconazole has led to the emergence of Candida albicans strains with decreased susceptibility to azoles. CMC is associated with an impaired Th17 cell response; however, it remains unclear whether decreased serum IL-17 and IL-22 levels are related to a defect in cytokine production or to neutralizing autoantibodies resulting from mutations in the AIRE gene.

A Novel Homozygous Mutation of the AIRE Gene in an APECED Patient From Pakistan: Case Report and Review of the Literature

Autoimmune-poly-endocrinopathy-candidiasis-ectodermal-dystrophy syndrome (APECED) is a rare monogenic recessive disorder caused by mutations in the autoimmune regulator (AIRE) gene. Criteria for the diagnosis of APECED are the presence of two of the following disorders: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism (CHP), and Addison's disease. APECED develops at high incidence in Finns, Sardinians, and Iranian Jews and presents with a wide range of clinical phenotypes and genotypes. In this manuscript, we report the clinical, endocrinological, and molecular features of a 16-year-old female patient from Pakistan living in Italy and presenting the major APECED clinical manifestations CMC, CHP, and primary adrenal insufficiency. Premature ovarian failure, chronic bronchopneumopathy, vitiligo, Hashimoto's thyroiditis emerged as associated diseases. In our patient, AIRE gene screening revealed the novel c.396G>C (p.Arg132Ser; p.R132S) mutation in homozygosity thus confirming APECED diagnosis. This is the first reported mutation within the nuclear localization signal (NLS) that is associated with APECED. The NLS mutation affects the nuclear import of classical transcription factors through nuclear pore by recognition of nuclear import receptors, the importin α molecules. By displaying crystal structures of the peptide containing the KRK basic residue cluster bound to α importins, we show that p.R132S replacement in 131-KRK-133 does not reproduce these interactions. Thus, we propose that the novel mutation exerts its pathogenetic effect by impairing the nuclear import of the Aire protein. The present case report is added to a limited series of Pakistani APECED patients who we reviewed from the scientific literature, mostly diagnosed on clinical findings.

APECED in Turkey: A case report and insights on genetic and phenotypic variability

APECED is a rare monogenic recessive disorder caused by mutations in the AIRE gene. In this manuscript, we report a male Turkish patient with APECED syndrome who presented with chronic mucocutaneous candidiasis associated with other autoimmune manifestations developed over the years. The presence of the homozygous R257X mutation of the AIRE gene confirmed the diagnosis of APECED syndrome. We further performed literature review in 23 published Turkish APECED patients and noted that Finnish major mutation R257X is common in Turks. In particular, we assessed retrospectively how often the Ferre/Lionakis criteria would have resulted in earlier diagnosis in Finns, Sardinians and Turks in respect to the classic criteria. Since an earlier diagnosis could have been possible in 18.8% of Turkish, in 23.8% of Sardinian and 38.55% of Finnish patients we reviewed from literature, Ferre/Lionakis criteria could indeed allow in future earlier initiation of immunomodulatory treatments, if found effective in future studies.

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.

Cytokine Autoantibody Screening in the Swedish Addison Registry Identifies Patients With Undiagnosed APS1

CONTEXT

Autoimmune polyendocrine syndrome type 1 (APS1) is a monogenic disorder that features autoimmune Addison disease as a major component. Although APS1 accounts for only a small fraction of all patients with Addison disease, early identification of these individuals is vital to prevent the potentially lethal complications of APS1.

OBJECTIVE

To determine whether available serological and genetic markers are valuable screening tools for the identification of APS1 among patients diagnosed with Addison disease.

DESIGN

We systematically screened 677 patients with Addison disease enrolled in the Swedish Addison Registry for autoantibodies against interleukin-22 and interferon-α4. Autoantibody-positive patients were investigated for clinical manifestations of APS1, additional APS1-specific autoantibodies, and DNA sequence and copy number variations of AIRE.

RESULTS

In total, 17 patients (2.5%) displayed autoantibodies against interleukin-22 and/or interferon-α4, of which nine were known APS1 cases. Four patients previously undiagnosed with APS1 fulfilled clinical, genetic, and serological criteria. Hence, we identified four patients with undiagnosed APS1 with this screening procedure.

CONCLUSION

We propose that patients with Addison disease should be routinely screened for cytokine autoantibodies. Clinical or serological support for APS1 should warrant DNA sequencing and copy number analysis of AIRE to enable early diagnosis and prevention of lethal complications.

Autoimmune polyendocrine syndrome type 1 in an Indian cohort: a longitudinal study

OBJECTIVE

Autoimmune polyendocrine syndrome type 1 (APS1) is a rare autosomal recessive disorder characterized by progressive organ-specific autoimmunity. There is scant information on APS1 in ethnic groups other than European Caucasians. We studied clinical aspects and autoimmune regulator (AIRE) gene mutations in a cohort of Indian APS1 patients.

DESIGN

Twenty-three patients (19 families) from six referral centres in India, diagnosed between 1996 and 2016, were followed for [median (range)] 4 (0.2-19) years.

METHODS

Clinical features, mortality, organ-specific autoantibodies and AIRE gene mutations were studied.

RESULTS

Patients varied widely in their age of presentation [3.5 (0.1-17) years] and number of clinical manifestations [5 (2-11)]. Despite genetic heterogeneity, the frequencies of the major APS1 components (mucocutaneous candidiasis: 96%; hypoparathyroidism: 91%; primary adrenal insufficiency: 55%) were similar to reports in European series. In contrast, primary hypothyroidism (23%) occurred more frequently and at an early age, while kerato-conjunctivitis, urticarial rash and autoimmune hepatitis were uncommon (9% each). Six (26%) patients died at a young age [5.8 (3-23) years] due to septicaemia, hepatic failure and adrenal/hypocalcaemic crisis from non-compliance/unexplained cause. Interferon-α and/or interleukin-22 antibodies were elevated in all 19 patients tested, including an asymptomatic infant. Eleven AIRE mutations were detected, the most common being p.C322fsX372 (haplotype frequency 37%). Four mutations were novel, while six others were previously described in European Caucasians.

CONCLUSIONS

Indian APS1 patients exhibited considerable genetic heterogeneity and had highly variable clinical features. While the frequency of major manifestations was similar to that of European Caucasians, other features showed significant differences. A high mortality at a young age was observed.

Childhood Polyarthritis As Early Manifestation of Autoimmune Polyendocrinopathy with Candidiasis and Ectodermal Dystrophy Syndrome

Autoimmune polyendocrinopathy with candidiasis and ectodermal dystrophy (APECED) is a rare disorder of immune dysregulation caused by mutations in the autoimmune regulator (AIRE) gene. Individuals affected with APECED develop a clinical syndrome characterized by ectodermal abnormalities, autoantibody production, and organ-specific autoimmune manifestations. Inflammatory arthritis is usually not described as a part of the syndrome, and only sporadic cases are reported. We describe the case of a preschool-age girl who presented with hypoparathyroidism, hepatitis, interstitial pneumonitis, and chronic polyarthritis at 4 years of age and was found to have two compound heterozygous disease-associated mutations in the AIRE gene. We also conducted a literature review of the main characteristics of inflammatory arthritis in APECED patients. Our case and review demonstrate that (1) inflammatory arthritis, although rare, can be an early manifestation of APECED; (2) the diagnosis of APECED should be considered if mucocutaneous candidiasis, multiple organ-specific autoimmune manifestations, polyendocrinopathy, especially hypoparathyroidism or adrenal failure, or ectodermal dystrophy accompany joint symptoms; and (3) genotyping interpretation should take into account that mutations are found in the 14 exons of the gene, compound heterozygosity is common, and in some cases, only one or no mutated alleles are found.

Redefined clinical features and diagnostic criteria in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare primary immunodeficiency disorder typically caused by homozygous AIRE mutations. It classically presents with chronic mucocutaneous candidiasis and autoimmunity that primarily targets endocrine tissues; hypoparathyroidism and adrenal insufficiency are most common. Developing any two of these classic triad manifestations establishes the diagnosis. Although widely recognized in Europe, where nonendocrine autoimmune manifestations are uncommon, APECED is less defined in patients from the Western Hemisphere. We enrolled 35 consecutive American APECED patients (33 from the US) in a prospective observational natural history study and systematically examined their genetic, clinical, autoantibody, and immunological characteristics. Most patients were compound heterozygous; the most common AIRE mutation was c.967_979del13. All but one patient had anti-IFN-ω autoantibodies, including 4 of 5 patients without biallelic AIRE mutations. Urticarial eruption, hepatitis, gastritis, intestinal dysfunction, pneumonitis, and Sjögren's-like syndrome, uncommon entities in European APECED cohorts, affected 40%-80% of American cases. Development of a classic diagnostic dyad was delayed at mean 7.38 years. Eighty percent of patients developed a median of 3 non-triad manifestations before a diagnostic dyad. Only 20% of patients had their first two manifestations among the classic triad. Urticarial eruption, intestinal dysfunction, and enamel hypoplasia were prominent among early manifestations. Patients exhibited expanded peripheral CD4+ T cells and CD21loCD38lo B lymphocytes. In summary, American APECED patients develop a diverse syndrome, with dramatic enrichment in organ-specific nonendocrine manifestations starting early in life, compared with European patients. Incorporation of these new manifestations into American diagnostic criteria would accelerate diagnosis by approximately 4 years and potentially prevent life-threatening endocrine complications.

Bloom syndrome

Bloom Syndrome (BS, MIM #210900) is an autosomal recessive genetic disorder caused by a mutation in the BLM gene, which codes for the DNA repair enzyme RecQL3 helicase. Without proper DNA repair mechanisms, abnormal DNA exchange takes place between sister chromatids and results in genetic instability that may lead to cancer, especially lymphoma and acute myelogenous leukemia, lower and upper gastrointestinal tract neoplasias, cutaneous tumors, and neoplasias in the genitalia and urinary tract. BS patients are usually of Ashkenazi Jewish descent and exhibit narrow facial features, elongated limbs, and several dermatologic complications including photosensitivity, poikiloderma, and telangiectatic erythema. The most concerning manifestation of BS is multiple malignancies, which require frequent screenings and strict vigilance by the physician. Therefore, distinguishing between BS and other dermatologic syndromes of similar presentation such as Rothmund-Thomson Syndrome, Erythropoietic Protoporphyria, and Cockayne Syndrome is paramount to disease management and to prolonging life. BS can be diagnosed through a variety of DNA sequencing methods, and genetic testing is available for high-risk populations. This review consolidates several sources on BS sequelae and aims to suggest the importance of differentiating BS from other dermatologic conditions. This paper also elucidates the recently discovered BRAFT and FANCM protein complexes that link BS and Fanconi anemia.

Diagnosis and classification of autoimmune parathyroid disease

Hypoparathyroidism (HP) is clinically characterized by the presence of hypocalcemia, usually associated with specific signs and symptoms that depend on how severe and chronic the disease becomes. HP is usually caused by surgical removal of all four parathyroids, while other forms are rarer. Autoimmune HP can occur as an isolated disease or as part of an autoimmune polyendocrine syndrome. Here we review what is known about parathyroid gland autoimmunity, focusing on recently-proposed parathyroid autoantibody markers, and particularly those directed against NACHT leucine-rich-repeat protein 5 and calcium-sensing receptor. We also describe the clinical characteristics of HP and design a diagnostic algorithm for autoimmune HP.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy from the pediatric perspective

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disease caused by mutations of the AutoImmune REgulator gene. The clinical spectrum of the disease encompasses several autoimmune endocrine and non-endocrine manifestations, which may lead to acute metabolic alterations and eventually life-threatening events. The clinical diagnosis is defined by the presence of at least two components of the classic triad including chronic mucocoutaneous candidiasis (CMC), chronic hypoparathyroidism (CH), Addison's disease (AD). Other common features of the disease are hypergonadotropic hypogonadism, alopecia, vitiligo, autoimmune hepatitis, Type 1 diabetes, gastrointestinal dysfunction. APECED usually begins in childhood. CMC is the first manifestation to appear, usually before the age of 5 yr, followed by CH and then by AD. The clinical phenotype may evolve over several years and many components of the disease may not appear until the 4th or 5th decade of life. The phenotypical expression of the syndrome shows a wide variability even between siblings with the same genotype. In view of this heterogeneity, an early diagnosis of APECED can be very challenging often leading to a considerable diagnostic delay. Therefore, clinicians should be aware that the presence of even a minor component of APECED in children should prompt a careful investigation for other signs and symptoms of the disease, thus allowing an early diagnosis and prevention of severe and life-threatening events. Aim of this review is to focus on clinical presentation, diagnosis and management of the major components of APECED in children particularly focusing on endocrine features of the disease.

APECED: A Paradigm of Complex Interactions between Genetic Background and Susceptibility Factors

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive disease, caused by mutations of a single gene named Autoimmune regulator gene (AIRE) which results in a failure of T-cell tolerance. Central tolerance takes place within the thymus and represents the mechanism by which potentially auto-reactive T-cells are eliminated through the negative selection process. The expression of tissue-specific antigens (TSAs) by medullary thymic epithelial cells (mTECs) in the thymus is a key process in the central tolerance and is driven by the protein encoded by AIRE gene, the transcription factor autoimmune regulator (AIRE). A failure in this process caused by AIRE mutations is thought to be responsible of the systemic autoimmune reactions of APECED. APECED is characterized by several autoimmune endocrine and non-endocrine manifestations and the phenotype is often complex. Although APECED is the paradigm of a monogenic autoimmune disorder, it is characterized by a wide variability of the clinical expression even between siblings with the same genotype, thus implying that additional mechanisms, other than the failure of Aire function, are involved in the pathogenesis of the disease. Unraveling open issues of the molecular basis of APECED, will help improve diagnosis, management, and therapeutical strategies of this complex disease.

Thyroid autoimmunity and polyglandular endocrine syndromes

Even though autoimmune thyroiditis is considered as the most emblematic type of organ-specific autoimmune disorder of autoimmunity, autoimmune thyroid diseases can be associated with other autoimmune endocrine failures or non-endocrine diseases (namely vitiligo, pernicious anemia, myasthenia gravis, autoimmune gastritis, celiac disease, hepatitis). Thyroid disorders, which are the most frequent expression of adult polyendocrine syndrome type 2, occur concomitantly with or secondarily to insulinodependent diabetes, premature ovarian failure, Addison's disease (Schmidt syndrome, or Carpenter syndrome if associated with diabetes). Testicular failure and hypoparathyroidism are unusual. The disease is polygenic and multifactorial. Disorders of thyroid autoimmunity are, surprisingly, very rare in polyendocrine syndrome type 1 (or APECED) beginning during childhood. They are related to mutations of the AIRE gene that encodes for a transcriptional factor implicated in central and peripheral immune tolerance. Hypothyroidism can also be observed in the very rare IPEX and POEMS syndromes.

Management of squamous cell cancer of the oesophagus in a patient with a polyglandular endocrinopathy (APECED) and achalasia

INTRODUCTION

We report a case of a 37-year-old man, with a background of a rare polyglandular autoimmune syndrome and achalasia, who developed an oesophageal tumour. Both autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) or type I polyglandular syndrome and achalasia confer increased risk of development of oesophageal squamous cell carcinoma.

METHODS

Despite having had multiple endoscopic examinations and dilatations in the recent past, this patient presented with dysphagia, and on endoscopy, he was found to have a mid-oesophageal tumour. A multidisciplinary team approach was vital in his management as careful monitoring of underlying disorders including Addison's disease and hypoparathyroidism were challenging during neoadjuvant chemoradiotherapy and in the perioperative period.

RESULTS

He made an uneventful recovery after a three-stage oesophagectomy, and histologically, he had a complete pathological response.

CONCLUSION

To our knowledge, this is the first successful outcome of a patient with APECED and oesophageal carcinoma in the literature.

Genetic basis of altered central tolerance and autoimmune diseases: a lesson from AIRE mutations

The thymus is a specialized organ that provides an inductive environment for the development of T cells from multipotent hematopoietic progenitors. Self-nonself discrimination plays a key role in inducing a productive immunity and in preventing autoimmune reactions. Tolerance represents a state of immunologic nonresponsiveness in the presence of a particular antigen. The immune system becomes tolerant to self-antigens through the two main processes, central and peripheral tolerance. Central tolerance takes place within the thymus and represents the mechanism by which T cells binding with high avidity self-antigens, which are potentially autoreactive, are eliminated through so-called negative selection. This process is mostly mediated by medullary thymic epithelia cells (mTECs) and medullary dendritic cells (DCs). A remarkable event in the process is the expression of tissue-specific antigens (TSA) by mTECs driven by the transcription factor autoimmune regulator (AIRE). Mutations in this gene result in autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), a rare autosomal recessive disease (OMIM 240300). Thus far, this syndrome is the paradigm of a genetically determined failure of central tolerance and autoimmunty. Patients with APECED have a variable pattern of autoimmune reactions, involving different endocrine and nonendocrine organs. However, although APECED is a monogenic disorder, it is characterized by a wide variability of the clinical expression, thus implying a further role for disease-modifying genes and environmental factors in the pathogenesis. Studies on this polyreactive autoimmune syndrome contributed enormously to unraveling several issues of the molecular basis of autoimmunity. This review focuses on the developmental, functional, and molecular events governing central tolerance and on the clinical implication of its failure.

Molecular background and genotype-phenotype correlation in autoimmune-polyendocrinopathy-candidiasis-ectodermal-distrophy patients from Campania and in their relatives

BACKGROUND

Autoimmune-polyendocrinopathy-candidiasis- ectodermal-distrophy (APECED) is a recessive disease, caused by mutations in the AutoImmune REgulator (AIRE) gene. Different mutations are peculiar of particular populations. In Italy, 3 hot spots areas where APECED shows an increased prevalence, have been identified in Sardinia, Apulia, and in the Venetian region.

AIM

In this study, we analyzed AIRE mutations and genotype-phenotype correlation in APECED patients originating from Campania and in their relatives.

PATIENTS AND METHODS

In 6 patients affected with APECED clinical findings, genetic analysis of AIRE, and APECED-related autoantibodies were performed.

RESULTS

All patients carried at least 1 mutation on exon 1 or on splice-site flanking exon 1. Two siblings carried a complex homozygous mutation [IVS1 + 1G>C; IVS1 + 5delG] on intron 1; 2 patients were compound heterozygous for [T16M]+[W78R] (exons 1+2); 1 patient was compound heterozygous for [A21V]+[C322fs] (exons 1+8) and another was homozygous for [T16M]+[T16M] on exon 1. Expression of the disease showed wide variability while circulating autoantibodies paralleled to phenotype in each patient. Analysis of relatives allowed the identification of 8 heterozygotes. None of heterozygous subjects presented major findings of APECED.

CONCLUSIONS

Mutations localized on exon 1 and the region flanking exon 1 are common in APECED patients originating from Campania. Genotype-phenotype correlation failed to reveal a relationship between detected mutations and clinical expression. Mutations in heterozygosis in AIRE gene are not associated to major findings of APECED.

Monogenic autoimmunity

Monogenic autoimmune syndromes provide a rare yet powerful glimpse into the fundamental mechanisms of immunologic tolerance. Such syndromes reveal not only the contribution of an individual breakpoint in tolerance but also patterns in the pathogenesis of autoimmunity. Disturbances in innate immunity, a system built for ubiquitous sensing of danger signals, tend to generate systemic autoimmunity. For example, defects in the clearance of self-antigens and chronic stimulation of type 1 interferons lead to the systemic autoimmunity seen in C1q deficiency, SPENCDI, and AGS. In contrast, disturbances of adaptive immunity, which is built for antigen specificity, tend to produce organ-specific autoimmunity. Thus, the loss of lymphocyte homeostasis, whether through defects in apoptosis, suppression, or negative selection, leads to organ-specific autoimmunity in ALPS, IPEX, and APS1. We discuss the unique mechanisms of disease in these prominent syndromes as well as how they contribute to the spectrum of organ-specific or systemic autoimmunity. The continued study of rare variants in autoimmune disease will inform future investigations and treatments directed at rare and common autoimmune diseases alike.

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy: insights into genotype-phenotype correlation

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is a rare autosomal recessive disease, caused by mutations of a single gene named autoimmune regulator gene (AIRE) which results in a failure of T cell tolerance within the thymus. Chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and Addison's disease are the hallmarks of the syndrome. APECED is also characterized by several autoimmune endocrine and nonendocrine manifestations, and the phenotype is often complex. Moreover, even though APECED is a monogenic disease, its clinical picture is generally dominated by a wide heterogeneity both in the severity and in the number of components even among siblings with the same AIRE genotype. The variability of its clinical expression implies that diagnosis can be challenging, and a considerable delay often occurs between the appearance of symptoms and the diagnosis. Since a prompt diagnosis is essential to prevent severe complications, clinicians should be aware of all symptoms and signs of suspicion. The aim of this paper is to give an overview on the clinical presentation and diagnostic criteria of APECED and to focus on current knowledge on genotype-phenotype correlation.

Microbiological screening of Irish patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy reveals persistence of Candida albicans strains, gradual reduction in susceptibility to azoles, and incidences of clinical signs of oral candidiasis without culture evidence

Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) are prone to chronic mucocutaneous candidiasis, which is often treated with azoles. The purpose of this study was to characterize the oral Candida populations from 16 Irish APECED patients, who comprise approximately half the total number identified in Ireland, and to examine the effect of intermittent antifungal therapy on the azole susceptibility patterns of Candida isolates. Patients attended between one and four clinical evaluations over a 5-year period, providing oral rinses and/or oral swab samples each time. Candida was recovered from 14/16 patients, and Candida albicans was the only Candida species identified. Interestingly, clinical diagnosis of candidiasis did not correlate with microbiological evidence of Candida infection at 7/22 (32%) clinical assessments. Multilocus sequence typing analysis of C. albicans isolates recovered from the same patients on separate occasions identified the same sequence type each time. Fluconazole resistance was detected in isolates from one patient, and isolates exhibiting a progressive reduction in itraconazole and/or fluconazole susceptibility were identified in a further 3/16 patients, in each case correlating with the upregulation of CDR- and MDR-encoded efflux pumps. Mutations were also identified in the ERG11 and the TAC1 genes of isolates from these four patients; some of these mutations have previously been associated with azole resistance. The findings suggest that alternative Candida treatment options, other than azoles such as chlorhexidine, should be considered in APECED patients and that clinical diagnosis of oral candidiasis should be confirmed by culture prior to the commencement of anti-Candida therapy.

Clinical heterogeneity and diagnostic delay of autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare autosomal recessive organ-specific autoimmune disorder that is characterized by a variable combination of (i) chronic mucocutaneous candidiasis, (ii) polyendocrinopathy and/or hepatitis and (iii) dystrophy of the dental enamel and nails. We analyzed the AIRE (autoimmune regulator) gene in subjects who presented any symptom that has been associated with APECED, including candidiasis and autoimmune endocrinopathy. We observed that 83.3% of patients presented at least two of the three typical manifestations of APECED, while the remaining 16.7% of patients showed other signs of the disease. Analysis of the genetic diagnosis of these subjects revealed that a considerable delay occurs in the majority of patients between the appearance of symptoms and the diagnosis. Overall, the mean diagnostic delay in our patients was 10.2 years. These results suggest that molecular analysis of AIRE should be performed in patients with relapsing mucocutaneous candidiasis for early identification of APECED.

Novel sequence variation of AIRE and detection of interferon-omega antibodies in early infancy

OBJECTIVE

Autoimmune polyendocrine syndrome type I (APS I) is a rare primary immunodeficiency disorder characterized by chronic mucocutaneous candidiasis, multi-organ autoimmunity and ectodermal dysplasia. Autoantibodies to parathyroid and adrenal glands and type I interferons (IFN) are hallmarks of APS I, which results from mutations in the autoimmune regulator (AIRE) gene. We wished to study clinical, immunological and genetic features of APS I in Hungarian patients, and to correlate anti-IFN-omega serum concentration with APS I and other multi-organ autoimmune diseases.

DESIGN

Detailed analysis of patients with APS I and multi-organ autoimmune diseases.

PATIENTS

Seven patients with APS I and 11 patients with multi-organ autoimmune diseases were studied.

MEASUREMENTS

Mutational analysis was performed by bidirectional sequencing of AIRE. Antibodies against IFN-omega and endocrine organ-specific autoantigens were studied with radioimmunoassay. RFLP was performed by digestion of DNA with Hin6I restriction enzyme.

RESULTS

AIRE sequence analysis revealed homozygous c.769C>T mutations in three patients and compound heterozygous sequence variants (c.769C>T/c.44_66dup26bp; c.769C>T/c.965_977del13bp; c.769C>T/c.1344delC) in four patients with APS I. All the six live patients tested had markedly elevated IFN-omega antibodies, which were not found in heterozygous siblings or parents. One of the identified patients was negative for antibodies against IFN-omega at 6 weeks of age, but became positive at 7 months. At age 1, he is still without symptoms of the disease. In contrast to patients with APS I, no AIRE mutation or elevation of IFN-omega antibodies were detected in patients with multi-organ autoimmune diseases.

CONCLUSION

This is the first overview of patients diagnosed with APS I in Hungary. A novel c.1344delC mutation in AIRE was detected. Anti-IFN-omega antibodies seem to appear very early in life and are helpful to differentiate APS I from other multi-organ autoimmune diseases.

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 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.

Evaluation of the autoimmune regulator (AIRE) gene mutations in a cohort of Italian patients with autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) and in their relatives

OBJECTIVE

Autoimmune-polyendocrinopathy-candidiasis-ectodermal-dystrophy (APECED) is a rare syndrome characterized by chronic candidiasis, chronic hypoparathyroidism and Addison's disease. APECED has been associated with mutations in autoimmune regulator (AIRE) gene. Our aim is to perform a genetic analysis of the AIRE gene in Italian APECED patients and in their relatives. Design AIRE mutations were determined by DNA sequencing in all subjects. Patients were tested for clinical autoimmune or non-autoimmune diseases, or for organ and non-organ specific autoantibodies.

PATIENTS

A total of 24 Italian patients with APECED (15 from the Venetian region, 2 from Southern-Tyrol, 4 from Apulia, 3 from Sicily), 25 relatives and 116 controls were studied.

RESULTS

Ten out of the 15 Venetian patients (66%) were homozygous for R257X or compound heterozygous with 1094-1106del13. One patient was homozygous for 1094-1106del13 and another for R139X. A novel mutation (1032-1033delGT) in combination with 1094-1106del13 was identified in one patient. No mutations were found in two cases. Two patients from Southern Tyrol were homozygous for R257X and for 1094-1106del13bp. All patients from Apulia were homozygous or heterozygous for W78R combined with Q358X. The patients from Sicily were homozygous for R203X or compound heterozygous with R257X. The analysis of the genotype-phenotype revealed that patients carrying 1094-1106del13 at the onset of Addison's disease were significantly older than those carrying other mutations. The genetic study of 25 relatives identified 20 heterozygous subjects. They suffered from various autoimmune and non-autoimmune diseases but no major disease of APECED was found.

CONCLUSION

These data demonstrate the great genetic heterogeneity for the AIRE mutations in Italian APECED patients, and that the heterozygosity for AIRE mutations do not produce APECED.

Sicilian family with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) and lethal lung disease in one of the affected brothers

INTRODUCTION

We report the clinical and immunological features of the autoimmune regulator gene (AIRE) in two Sicilian brothers with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). They were compound heterozygotes with R203X/R257X. Both had oral candidiasis since the first year of life and later developed hypoparathyroidism and Addison disease. The elder brother had experienced recurrent lower respiratory infections since 5 years of age and over the years developed severe obstructive lung disease with bronchiectasis, which led to death at 18 years of age. Both brothers had circulating autoantibodies against tryptophan hydroxylase and serotonin-producing cells were absent in the duodenal mucosa. This was associated with intestinal dysfunction in only the elder brother.

CONCLUSION

(1) In the first Sicilian family with APECED reported up to now we found a heterozygous mutation that had been previously reported only once. (2) In the older brother of this family we observed a severe and lethal lung disease; this case adds to a growing literature describing this association between APECED and respiratory illnesses. (3) Tryptophan hydroxylase antibodies might be hypothesized to be the marker of an autoimmune gastrointestinal illness possibly associated with APECED.

Lessons on immune tolerance from the monogenic disease APS1

Autoimmunity is a complex disease process that results from a breakdown in the ability of the immune system to discriminate self from non-self. One approach to unraveling how autoimmunity occurs is to study monogenic diseases, for which a single gene defect is responsible. Recent work on the monogenic autoimmune disease 'autoimmune polyglandular syndrome type 1' (APS1) and on the causal gene of this disorder--autoimmune regulator (AIRE)--is providing new lessons on how immune tolerance is maintained.