(11.01) A Case of Autoimmune Polyendocrine Syndrome Type 2

Autoimmune polyglandular syndromes (APS) are a rare group of polyendocrine conditions that include multiple glandular deficiencies associated with other autoimmune diseases. There are three types of APS, of which APS type 2 (APS-2) is the most common. APS-2 is defined by the presence of Addison’s disease associated with autoimmune thyroid disease and/or diabetes mellitus type 1.


Case(s) Description :

The patient is a 61-year-old male with a past medical history of hypertension and prostate cancer status post prostatectomy, who was sent to the hospital by primary care physician for hyponatremia and hypotension despite discontinuing antihypertensives. The patient reported that he has had generalized weakness and chronic fatigue for several months, feeling cold all the time and occasional lower extremity swelling. He denied chest pain, palpitations, shortness of breath, changes in bowel habits, tremors, dizziness, lightheadedness, numbness, tingling or changes in hair/nails/skin. Vitals on arrival showed systolic blood pressure in the 90s and diastolic blood pressure in the 60s. Physical exam was unremarkable including a non-enlarged and non-tender thyroid. Labs showed hyponatremia at 123 mmol/L (135- 145 mmol/L), TSH 68.82 mcIntlUnit/mL (0.34-5.60 mcIntlUnit/mL), FT4 0 ng/dL (0.58-1.64 ng/dL) and TT3 0.18 ng/mL (0.87- 1.87 ng/mL). Given hyponatremia and hypotension, there was a concern for adrenal insufficiency, so a random cortisol was ordered, which came back low at 2.0 mcg/dL. The patient also had elevated thyroid peroxidase antibodies, consistent with likely autoimmune thyroiditis. Patient was started on intravenous hydrocortisone and levothyroxine. He had improvement in weakness, hyponatremia and blood pressure. Hydrocortisone was tapered down to physiological dose. The patient was discharged on oral levothyroxine and a physiological dose of hydrocortisone. He was also scheduled for outpatient follow-up with plans for a cosyntropin stimulation test to confirm Addison’s disease.


Discussion :

APS-2 is the most common of the polyendocrine syndromes. It is more common in women than men in a 3:1 ratio and presents in the 3^rd or 4^th decades of life. Autoimmune thyroiditis is the most common initial presentation. Adrenal insufficiency may be concurrent, may be delayed in onset for up to two decades, or may never manifest. This case is unique because of the concurrent presentation of autoimmune thyroiditis and adrenal insufficiency. Unlike the common age of presentation, the patient presented at a much later age. Though a cosyntropin stimulation test is pending, initial presentation of autoimmune thyroiditis alone in the 6^th decade of life is unusual.