Autoimmune polyendocrine syndrome

Autoimmune polyendocrine syndrome
Classification and external resources
Specialty
ICD-10	E31.0
ICD-9-CM	258.1
OMIM	240300 269200
DiseasesDB	29212 29690
eMedicine	med/1867 med/1868
Patient UK	Autoimmune polyendocrine syndrome
MeSH	D016884

In medicine, autoimmune polyendocrine syndromes, also called polyglandular autoimmune syndrome (PGAS), are a heterogeneous group of rare diseases characterized by autoimmune activity against more than one endocrine organ, although non-endocrine organs can be affected.

There are three "autoimmune polyendocrine syndromes", and a number of other diseases which have endocrine autoimmunity as one of their features.

The syndromes

• Autoimmune polyendocrine syndrome type 1 (APECED or Whitaker's syndrome)
• Autoimmune polyendocrine syndrome type 2
• The most serious but rarest form is the X-linked polyendocrinopathy, immunodeficiency and diarrhea-syndrome, also called XLAAD (X-linked autoimmunity and allergic dysregulation) or IPEX (immune dysfunction, polyendocrinopathy, and enteropathy, X-linked). This is due to mutation of the FOXP3 gene on the X chromosome. Most patients develop diabetes and diarrhea as neonates and many die due to autoimmune activity against many organs. Boys are affected, while girls are carriers and might suffer mild disease.

Other diseases

Other diseases featuring polycrine autoimmunity:

• Chromosomal abnormalities (Down syndrome) increase the risk of endocrine autoimmunity
• POEMS syndrome - the E is for endocrinopathy; the cause is a paraprotein excreted by a plasmacytoma or multiple myeloma; other features are polyneuropathy, organomegaly (hepatomegaly and splenomegaly), M-protein (paraprotein) and skin changes.
• Several very rare diseases including Lupus and Addison's Disease.

Management

In principle, the component diseases are managed as usual. The challenge is to detect the possibility of any of the above syndromes, and to anticipate other manifestations. For example, in a patient with known Type 2 autoimmune polyendocrine syndrome but no features of Addison's disease, regular screening for antibodies against 21-hydroxylase (a feature of Addison's) may prompt early intervention and hydrocortisone replacement to prevent characteristic crises.