Activating Autoantibodies against the Calcium-Sensing Receptor Detected in Two Patients with Autoimmune Polyendocrine Syndrome Type 1

Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder caused by mutations in the autoimmune regulator (AIRE) gene. Hypoparathyroidism occurs in 80% of patients with APS1 and has been suggested to result from an autoimmune reaction against the calcium-sensing receptor (CaSR) in parathyroid cells. Anti-CaSR binding antibodies have previously been detected in patients with APS1.The aim of this study was to determine...