Autoimmune Polyglandular Syndrome Type III: A Case Report of a Diagnostic Challenge in a Middle-Age Woman
Keywords:
thyroiditis, pernicious anemia, autoimmune polyglandular syndrome type 3, latent autoimmune diabetes in adults (LADA)Abstract
Introduction: Autoimmune Polyglandular Syndrome Type III (APS III) is characterized by the coexistence of autoimmune thyroid disease with other autoimmune disorders, excluding adrenal insufficiency. It remains underdiagnosed due to its variable and often non-specific clinical presentation.
Case Presentation: We report the case of a middle-aged female with a known history of autoimmune hypothyroidism who presented with symptoms of anemia and poor glycemic control. Laboratory investigations revealed positive anti-parietal cell antibodies, elevated intrinsic factor antibodies, and vitamin B12 deficiency consistent with pernicious anemia. She was also diagnosed with latent autoimmune diabetes in adults (LADA), based on positive anti-GAD antibodies and suboptimal glycemic response. These findings fulfilled the criteria for APS Type III. The patient responded well to vitamin B12 supplementation and insulin therapy, with marked improvement in hematological and metabolic parameters.
Conclusion: APS type III can manifest with non-specific or overlapping clinical features, which may contribute to delayed identification. Clinicians should maintain a high level of suspicion in patients with already diagnosed autoimmune disorders.
