Autoimmune polyendocrine syndrome in type 1 diabetes: why formal diagnosis matters for clinical utility.

In response to Huang et al., we clarify the take-home message of our study on autoimmune polyendocrine syndrome (APS) in type 1 diabetes mellitus (T1DM). Existing guidelines recommend screening T1DM patients for thyroid and celiac diseases. When positive, there is a lack of guidance on how to proceed. Nevertheless, if T1DM patients do have AITD or celiac disease, they qualify for an APS diagnosis, which signals a high pretest probability for additional autoimmunity. Our data show that among 198 patients meeting APS criteria at baseline, only 17/198 (8.6%) had a formal APS diagnosis documented in their medical records. Extended screening uncovered new autoantibody positivity in 39% and new autoimmune diseases in 11.5% of patients. In the end, this led us to signal an under-recognition of APS in T1DM. Based on this evidence, we do not advocate for universal, broad screening panels in routine practice. Instead, we argue that formal diagnostic recognition and medical record documentation of APS are essential first steps to prevent fading clinical awareness and trigger lifelong vigilance.