Polyglandular Autoimmune Syndrome Type 2 (PAS-2)

Diagnosis criteria for polyglandular autoimmune syndrome type 2 (PAS-2) are autoimmune adrenocortical insufficiency with autoimmune thyroiditis and/or type I diabetes mellitus.

Description

PAS-2 is also known as Schmidt’s syndrome when adrenalitis is associated with thyroiditis and Carpenter’s syndrome for adrenalitis with hypoparathyreosis. Gonadal failure or vitiligos are frequently described as part of PAS II. Other conditions include celiac disease, autoimmune hepatitis, alopecia, pernicious anemia, and myasthenia gravis.

Symptoms

Depends on the organ affected.

Diagnosis/Treatment

Depends on the organ affected. Treatment involves life-long follow up and screening for another glandular failure in patients already diagnosed with PAS-2.

Incidence

PAS-2 is a relatively rare disease. Its prevalence is 1.5-2: 100 000. It is two times more frequent among women. The first signs of PAS-2 usually develop between 20–30 years of age.

Pathogenesis

Addison’s disease occurs when more than 90% of adrenal gland tissue is destroyed (primary Addison’s disease). The destruction can occur due to various causes:

Circumstantial Evidence:

  • PAS-2 is associated with DQA1*0501, DQB1*0201 (DQ2) and, because of the linkage disequilibrium (non-random association), with A1, B8, and DR3
  • Approximately 50 percent of PAS-2 cases are familiar. The pattern of inheritance is consistent with autosomal dominance with incomplete penetration

Indirect Evidence

  • Mouse model: NOD mice show histological signs of adrenalitis, thyroiditis, sialitis, and parathyroiditis.