Autoimmune polyglandular syndromes: interplay between the immune and the endocrine systems leading to a diverse set of clinical diseases and new insights into immune regulation

Novel Gene Mutations Regulating Immune Responses in Autoimmune Polyglandular Syndrome With an Atypical Course

Context

Autoimmune polyglandular syndrome (APS) is a cluster of endocrine disorders arising from immune dysregulation, often combined with damage to nonendocrine organs. There are 2 types of APS: type 1 and type 2 (APS-1 and APS-2, respectively). In clinical practice, an atypical course of APS is often observed.

Objective

This work aims to find a novel genetic predictor of APS.

Methods

We performed exome sequencing in 2 patients with an atypical clinical APS picture and members of their families. Patient A presented with a manifestation of APS-2 in early childhood and patient B with a late manifestation of the main components of APS-1.

Results

In patient B, we identified inherited compound mutations as a novel combination of the c.769C > T and c.821delG alleles of AIRE and genetic variation in the CIITA gene. No homozygous or compound mutations in AIRE were found in patient A, but we did reveal mutations in genes encoding regulatory proteins of innate and acquired immunity in this patient.

Conclusion

Our data revealed novel combination of mutations in the AIRE gene in atypical APS and imply that mutations in immune-related genes may modify the clinical manifestation of APS in AIRE-mutation carriers and contribute to the development of autoimmune pathology in non-AIRE carriers with atypical APS.

Co-Occurrence of Systemic Lupus Erythematosus and Autoimmune Polyendocrine Syndrome II: Is There a Pathologic Link?

Autoimmune polyendocrine syndrome type II (APS II) is a rare endocrine disorder that involves the adrenal gland (Addison's disease), thyroid (autoimmune thyroiditis), pancreas (type 1 diabetes), and other non-endocrine organs. Herein, we report a case of a 58-year-old woman with a past medical history of systemic lupus erythematosus (SLE) and Addison's disease, who initially presented with nocturia, polyuria, abnormal sweating, fatigue, hair thinning, heat and cold intolerance, and progressive darkening of the skin for the last few months. After a thorough evaluation, she was diagnosed with autoimmune thyroiditis, and thus, she met the criteria for APS II. This report highlights the unusual presentation of APS II in a patient with SLE. We also discuss common pathophysiological mechanisms that can explain the concurrence of SLE and APS II in this patient.

Association of autoimmune thyroid diseases, chronic atrophic gastritis and gastric carcinoid: experience from a single institution

PURPOSE

Autoimmune polyendocrine syndromes (APS) type III are characterized by the association of autoimmune thyroid disease (ATD) with other autoimmune diseases such as diabetes, alopecia, pernicious anemia, vitiligo and chronic atrophic gastritis. A strong association between ATD and atrophic gastritis (AG) has been demonstrated. Moreover 10 % of patients affected by AG have a predisposition to develop gastric carcinoid and adenocarcinoma as a result of chronic hypergastrinemia caused by achlorhydria and subsequent ELC cells neoplastic transformation.

METHODS

The aim of the study is to evaluate, in a consecutive series of patients followed for ATD in our outpatients clinic, the prevalence of AG. In the period 2004-2014, 242 patients with ATD underwent a screening performing APCA, Vitamin B12, ferritin, iron, and hemoglobin and red cells count measurements with subsequent gastroscopy in case of APCA positivity.

RESULTS

We found 57/242 (23.5 %) patients with APCA positivity. Of these patients 33/57 (57.8 %), 31 F and 2 M, were affected by Graves disease; 24/57 (42.1 %) 21 F and 3 M by Hashimoto thyroiditis; 10/57 (17.5 %) presented with anemia, 14/57 (24.5 %) with vitamin B12 deficiency, 9/57 (15.7 %) with iron deficiency. In 2/57 a gastric carcinoid was found.

CONCLUSIONS

Our data confirm the high association rate of AG in ATD which frequently is not an isolated disease but configure the picture of APS type III and need to be followed accordingly. An early diagnosis may be useful for diagnosis of gastric carcinoids and to explain and treat a gastric related L-thyroxine malabsorption and presence of chronic unexplained anemia.

[Polyglandular autoimmune syndromes : An overview]

Polyglandular autoimmune syndromes (PGAS), also known as autoimmune polyendocrinopathy syndromes (APS), are a heterogeneous group of rare, genetically caused diseases of the immune system which lead to inflammatory damage of various endocrine glands resulting in malfunctions. In addition, autoimmune diseases of non-endocrine organs may also be found. Early diagnosis of PGAS is often overlooked because of heterogeneous symptoms and the progressive occurrence of the individual diseases. The two most important forms of PGAS are the juvenile and adult types. The juvenile type (PGAS type 1) is caused by mutations in the autoimmune regulator (AIRE) gene on chromosome 21, exhibits geographic variations in incidence and is defined by the combination of mucocutaneous candidiasis, Addison's disease and hypoparathyroidism. In addition, autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome and other autoimmune diseases can also occur. The adult form of PGAS (PGAS type 2) is a multigenetic disorder associated with some HLA haplotypes, is more common than the juvenile type, shows female predominance and exhibits the combination of type 1 diabetes, autoimmune thyroid disease, Addison's disease and other autoimmune disorders. The histological alterations in affected organs of PGAS patients are similar to findings in sporadically occurring autoimmune diseases of these organs but there are no pathognomic fine tissue findings. If patients exhibit autoimmune changes in two different endocrine glands or if there are indications of several autoimmune disorders from the patient history, it is important to consider PGAS and inform the clinicians of this suspicion.