Autoimmune Polyendocrine Syndrome

Overview

Autoimmune polyendocrine syndrome (APS) refers to a group of uncommon conditions in which the body's immune system mistakenly attacks more than one of its own hormone-producing (endocrine) glands. Because several glands are affected, a person can develop a combination of hormone deficiencies, such as an underactive adrenal gland together with thyroid or other gland problems. Some forms also involve non-endocrine autoimmune problems affecting the skin, gut, or other tissues.

Doctors describe two main patterns. Type 1 is rare, usually begins in childhood, is caused by changes in a single gene, and classically combines a yeast infection of the skin and mucous membranes, underactive parathyroid glands, and adrenal failure. Type 2 is more common, usually appears in adults, runs in families, and combines adrenal failure with autoimmune thyroid disease and/or type 1 diabetes. While the syndrome cannot be cured, the individual hormone deficiencies can usually be treated effectively with hormone replacement, and ongoing monitoring is important because new gland problems can appear over time.

Symptoms

Symptoms depend on which glands are affected and which hormones are lacking, and they may appear one at a time over years.

• Fatigue, weakness, weight loss, low blood pressure, and darkening of the skin (adrenal failure)
• Tiredness, weight changes, and temperature intolerance (thyroid disease)
• Increased thirst and urination and high blood sugar (type 1 diabetes)
• Muscle cramps and tingling from low calcium (underactive parathyroid glands)
• Persistent skin or mouth yeast infections (in type 1)
• Other features such as patchy hair or skin color loss, anemia, or digestive problems

Because a sudden worsening of adrenal failure (an adrenal crisis) can be life-threatening, symptoms such as severe weakness, vomiting, and very low blood pressure need urgent attention.

Causes

Autoimmune polyendocrine syndrome is caused by the immune system attacking the body's own glands. The underlying triggers differ by type.

• Type 1: Caused by changes (mutations) in a single gene that normally helps the immune system tolerate the body's own tissues. It is inherited in a pattern that usually requires an affected gene from both parents.
• Type 2: Results from a combination of multiple genes and likely environmental factors, and tends to cluster in families rather than following a single-gene pattern.

In both types, immune cells and antibodies damage gland tissue, gradually reducing hormone production.

Risk Factors

• A family history of autoimmune endocrine disease
• Having one autoimmune gland disorder, which raises the chance of others
• Specific inherited genes (especially for type 1)
• Female sex (more common in type 2)
• Other personal autoimmune conditions such as vitiligo or pernicious anemia

Diagnosis

Diagnosis involves identifying failure of more than one gland and confirming an autoimmune cause.

• Hormone blood tests: Measuring levels from the adrenal, thyroid, parathyroid, and pancreas to detect deficiencies.
• Autoantibody tests: Detecting antibodies against specific glands that point to an autoimmune process.
• Blood chemistry: Checking blood sugar, calcium, sodium, and potassium.
• Genetic testing: Used in some cases, particularly to confirm type 1.
• Ongoing screening: Periodic testing because new gland problems can develop after the first diagnosis.

Treatment

There is no cure, but each hormone deficiency can usually be treated, and the focus is on replacing missing hormones and monitoring for new problems.

• Hormone replacement: Steroid hormones for adrenal failure, thyroid hormone for thyroid deficiency, calcium and vitamin D for low parathyroid function, and insulin for type 1 diabetes.
• Treating other features: Antifungal medicines for persistent yeast infections in type 1, and care for related conditions as needed.
• Emergency planning: People with adrenal failure are taught to increase steroids during illness and to carry an emergency injection and medical identification to prevent an adrenal crisis.
• Regular follow-up: Ongoing monitoring by an endocrinologist to adjust treatment and catch newly affected glands early.

With proper hormone replacement and monitoring, many people lead full lives, though lifelong treatment is required.

Prevention

• The syndrome itself cannot be prevented, but complications can be reduced
• Keep up with regular monitoring to detect new gland problems early
• Take hormone replacement exactly as prescribed
• Learn sick-day rules for adrenal insufficiency and carry an emergency kit
• Wear medical identification noting adrenal insufficiency
• Inform relatives, who may benefit from screening

When to See a Doctor

See a doctor if you have symptoms of a hormone problem such as persistent fatigue, weight loss, increased thirst, muscle cramps, or skin changes, especially if you already have one autoimmune gland condition. Seek emergency care immediately for signs of an adrenal crisis, including severe weakness, vomiting, abdominal pain, confusion, and very low blood pressure or fainting, as this is life-threatening and needs urgent steroid treatment. Carry medical identification if you have adrenal insufficiency.

Related Topics

Frequently Asked Questions

References

1. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
2. MedlinePlus, U.S. National Library of Medicine. Autoimmune polyglandular syndrome.
3. National Organization for Rare Disorders (NORD).
4. Genetic and Rare Diseases Information Center (GARD).