Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED)

Abstract

Autoimmune polyglandular syndrome type 1 or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (Online Mendelian Inheritance in Man 2403000) is a rare monogenic disorder caused by a breakdown in the immune tolerance mechanism toward 'self' and resulting in a pattern of autoimmune manifestations usually involving multiple organs. It is a recessive-inherited autosomal form caused by loss-of-function mutations in the autoimmune regulator gene, which is located in the region q22.3 of the chromosome 21. Although rare, the disease is more common in certain populations, particularly in Finland (prevalence 1:25.000), Sardinia (1:14.000), and among Iranian Jews (1:9.000). The clinical signs are characterized by chronic candidiasis, hypoparathyroidism, and Addison's disease, which might associate with other endocrine and nonendocrine manifestations, such as chronic mucocutaneous candidiasis and ectodermal dystrophies. Importantly, patients suffer from chronic Candida infections which might reflect defects in the T cell response to pathogens but also the increased production of anticytokine antibodies increasing the sensitivity to infections.