Autoimmune Polyendocrine Syndrome type II (APS2) describes the onset of multiple disorders involving the dysfunction of hormone-producing organs due to autoimmunity. All APS2 cases exhibit Addison’s disease (AD), caused by autoimmune destruction of the adrenal glands. Forms of APS2 constitute additional autoimmune diseases of the thyroidand pancreatic glands. Autoimmune thyroid disordersincludeHashimoto’s Thyroiditis (hypothyroidism) and Grave’s Disease (hyperthyroidism). Pancreatic autoimmunity leads to insulin dependent diabetes mellitus (IDDM).The association of AD withhypothyroidism is most common among APS2 cases, while the association of all three glandular disorders, representing the complete form of APS2, is least common, with an estimated prevalence of 1.4-4.5 cases per 100,000 individuals.APS2 is the most common immunoendocrinopathy syndrome; approximately 75% of affected cases are female, and the age of onset occurs typically after the third decade of life. APS2 cases can further develop relativelyminor autoimmune diseases including vitiligo, atrophic gastritis, pernicious anemia,hypergonodotropic hypogonadism, and celiac disease.
Lymphoplasmacytic infiltration of adrenal, thyroid, and pancreatic glands is the primary pathological process in APS2.Circulating autoantibodies target specific self-antigens, blocking organ activity (AD, hypothyroidism, IDDM), or stimulating organ activity (hyperthyroidism). Diagnosis involves organ imaging and autoantibody screening following the onset of symptoms pertaining to the autoimmune disorders. Management of APS2 involves hormone replacement therapy with the exception of hyperthyroidism and celiac disease treatment. Due to the variable latency in the onset between specific disordersin APS2, cases with monoglandular autoimmune diseasemust undergo repeated screening of organ-specific autoantibodies.
Qari and Damnan (2000) presented three cases of autoimmune polyglandular syndrome type 2 (APS2) in a Saudi Arabian family. The first patient, a 58 year old female, was initially diagnosed with Hashimoto’s hypothyroidism and with insulin dependent diabetes mellitus (IDDM) prior to the current diagnosis. Her clinical presentation included dizziness, fatigue, hyperpigmentation, postural hypotension, and premature onset of menopause. A positive corticotropin stimulation test, and electrolyte abnormalities including hyponatremia and hyperkalemia, lead to diagnosis of Addison’s disease (AD). With no history of chronic infections or cancer, the cause of AD was attributed to autoimmune adrenalitis. Measurement of thyroid autoantibodies confirmed autoimmune hypothyroidism, leading to diagnosis of the complete form of APS2, with hypogonadism. She was treated with hydrocortisone, fludrocortisone, thyroxin, and hypoglycemic drugs. Electrolyte abnormalities normalized, thyroid function was restored, and no other autoimmune diseases developed. Her 36-year old daughter presented with similar symptoms but did not present with IDDM nor ovarian failure. She was diagnosed with AD and hypothyroidism, and was treated with hydrocortisone, fludrocortisone, and thyroxin. The older patient's 14 year-old granddaughter was diagnosed with AD and was treated with hydrocortisone. Organ specific autoantibody screening for the remainder of the family was attempted, however the samples were lost and the test was not repeated.