Endocrine Abstracts

JOINT2603

Introduction: Autoimmune diseases share a common predisposition and can coexist in the same patient. Type 1 diabetes, hyperthyroidism, and myasthenia gravis have similar immunopathological bases. The coexistence of these three conditions is rarely reported in the literature but has significant diagnostic, therapeutic, and prognostic implications. We report a case of this association.

Case Report: A 23-year-old male was diagnosed with type 1 diabetes in December 2022 at the age of 21 and he was managed with a basal-bolus insulin regimen. During follow-up, he reported progressive fatigue worsening throughout the day and dysphagia. Clinical examination revealed left eyelid ptosis, leading to a diagnosis of myasthenia gravis in February 2023. He was hospitalized in the neurology department and treated with pyridostigmine 480 mg/day and corticosteroids, with good clinical improvement. During a subsequent hospitalization in June 2023, the patient presented with weight loss, polyphagia, palpitations, and diarrhea. Examination revealed a small, homogeneous goiter, inactive bilateral exophthalmos, and distal tremors. Laboratory tests showed TSH < 0.014 µUI/ml, FT4: 88.4 pmol/l, positive anti-TPO antibodies at 90.8 UI/ml, negative anti-TG antibodies. Based on these findings, Graves’ disease was suspected, and the patient was started on thiamazole 30 mg/day and propranolol 120 mg/day.

Conclusion: These conditions highlight the complex interplay between autoimmunity, genetics, and immune dysfunction. A gene associated with early-stage type 1 diabetes and myasthenia gravis (sialitis and peri-insulitis) has been mapped to chromosome 1 near the Bcl-2 locus. Additionally, the CTSL2 gene, encoding cathepsin V, a cysteine protease involved in antigen presentation in human cortical thymic epithelial cells, may play a role in the autoimmunity of these three diseases. A personalized approach is essential for diagnosis, treatment, and long-term follow-up of these patients.