APS Crossover: A Multiglandular Challenge

Abstract Autoimmune polyglandular syndromes (APS) involve dysfunction of multiple endocrine glands due to immune system dysregulation, often presenting in a progressive or overlapping pattern. This report details the case of a 26-year-old woman with poorly controlled type 1 diabetes mellitus who presented with diabetic ketoacidosis. Further clinical assessment revealed primary amenorrhea, short stature, and absent secondary sexual characteristics, prompting an expanded endocrine evaluation. Workup demonstrated autoimmune thyroid disease, confirmed by elevated thyroid stimulating hormone and anti-thyroid peroxidase antibodies, along with positive glutamic acid decarboxylase antibodies supporting the autoimmune etiology of her diabetes. Hormonal analysis revealed low gonadotropins suggestive of hypogonadotropic hypogonadism, while PTH levels were raised despite normal calcium and phosphorus, indicating early parathyroid involvement. Adrenal function and pituitary imaging were normal. Although the absence of adrenal insufficiency rules out classic APS type 2, the range of findings does not fit neatly into any one category, raising the possibility of an evolving syndrome with overlapping features of APS types 2, 3, and 4. This case illustrates the spectrum-like presentation of adult-onset autoimmune endocrinopathies and underscores the importance of ongoing evaluation for latent or emerging glandular involvement.