FFinalistSouthampton · 2027
Endocrine
AKT · Endocrine/Paraneoplastic & neuroendocrinelow yield

Polyglandular autoimmune syndromes

Autoimmune failure of multiple endocrine glands (APS-1, APS-2)

Overview

Autoimmune destruction of several endocrine glands together. APS type 1 (AIRE gene, childhood): the triad of chronic mucocutaneous candidiasis, hypoparathyroidism and Addison's disease. APS type 2 (Schmidt, adults, commoner): Addison's disease with autoimmune thyroid disease and/or type 1 diabetes. Recognise the clustering — one autoimmune endocrinopathy should prompt looking for the others.

Recognise

  • APS-1 (childhood): mucocutaneous CANDIDIASIS + HYPOPARATHYROIDISM + ADDISON'S (± other organ-specific autoimmunity)
  • APS-2 (adults, commonest): ADDISON'S + autoimmune THYROID disease and/or type 1 DIABETES
  • Often other autoimmune disease (vitiligo, pernicious anaemia, coeliac, premature ovarian insufficiency)

Red flags

  • Underlying Addisonian crisis risk; new autoimmune endocrinopathy → screen for the others

Differentials & how to tell them apart

Isolated autoimmune endocrinopathya single gland affected without the cluster
MEN syndromestumours (neoplasia), not autoimmune destruction

Investigations

Hormone profiles of the involved glands (cortisol/ACTH, calcium/PTH, TFTs, glucose) + relevant autoantibodies (21-hydroxylase, TPO, GAD); AIRE genetics (APS-1); screen periodically.

Management

Replace each deficient gland + screen for and monitor the others

  1. 1When one autoimmune endocrinopathy is found, SCREEN for the others (the syndrome clusters). Replace each deficient hormone — glucocorticoid before thyroxine if both adrenal and thyroid are involved.Gate: In combined adrenal + thyroid disease, replace GLUCOCORTICOID before levothyroxine (thyroxine first can precipitate an adrenal crisis); one autoimmune gland failure should trigger looking for the cluster
  2. 2Lifelong replacement and periodic re-screening for emerging endocrinopathies; family awareness.
Replace each deficient hormone — glucocorticoid/mineralocorticoid (Addison), levothyroxine, insulin, calcium/vitamin D (hypoparathyroidism)
Treat candidiasis (APS-1) — antifungals

Key points

Clusters of autoimmune endocrine failure: APS-1 = candidiasis + hypoparathyroidism + Addison's (kids); APS-2 = Addison's + thyroid ± T1DM (adults). Find one → look for the rest; steroid before thyroxine.

Monitor & prognosis

Periodic hormone screening; new autoimmunity.

Good on replacement.

Source: Society for Endocrinology