Abstract: This disclosure describes methods and compositions for detecting the presence of autoantibodies associated with autoimmune polyglandualar syndrome 1 (APS1) in a biological sample. In particular, detection of APS1-specific autoantibodies that specifically bind to certain APS1 associated autoantigens in such methods is described. Also provided are methods of treating subjects with APS1 or at risk of developing APS1 associated conditions. Also provided are devices and kits useful for the diagnosis and prognostic assessment of subjects having APS1 and for assessing subject risk at developing particular APS1-associated conditions.