ODP043 Hypokalemia in Autoimmune Polyglandular Syndrome: A Case of Newfound Type I (Distal) Renal Tubular Acidosis

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy Type 1 (APECED) is a rare autosomal recessive disorder predisposing to early development of chronic mucosal candidiasis and progressive development of various endocrinopathies, such as Addison's disease, Primary Hypoparathyroidism, and Type 1 Diabetes (T1D). Few cases described in literature regarding renal involvement in this disorder, with most common manifestation being tubulo-interstitial nephritis, however, there is limited evidence regarding presentation of APECED with hypokalemia due to concomitant Type I Renal Tubular Acidosis (RTA). Case of a 47-year-old female with past medical history of APECED Type 1 (consisting of hypoparathyroidism, adrenal insufficiency, and chronic mucocutaneos candidiasis), T1DM on honeymoon, hypothyroidism, and nephrolithiasis presenting to the emergency department complaining of bilateral upper and lower extremity weakness of one week in evolution, but worsening on day of admission. Denies associated constitutional symptoms. Strong positive first-degree relative history for autoimmune diseases. Physical examination: 2/5 strength in all four extremities, deep tendon reflexes grossly intact, no gross sensory or motor deficits. Patient on oral steroid therapy for her Addison's, calcitriol supplementation for hypoparathyroidism, and potassium chloride supplementation since a prior hypokalemic episode 17 years ago. Laboratory workup results remarkable for sodium: 140 mmol/L (N: 135-144 mmol/L), chloride: 110 mmol/L (N: 95-105 mmol/L), potassium: 2. 0 mmol/L (N: 3.4-4.5 mmol/L), central bicarbonate: 18mmol/L (N: 23-31 mmol / L), anion gap: 12 (N: 10-12), glycosylated hemoglobin: 5.2% (N: 4.7-6.2%) and anti-glutamic acid decarboxylase antibodies >25,000 U/mL (N: