Endocrine Abstracts

Background: Autoimmune Polyglandular Syndrome Type 3A (APS-3A) comprises autoimmune thyroid disease with type 1 diabetes mellitus (T1DM) in the absence of adrenal involvement. Concurrent metabolic crises are rare and diagnostically challenging.

Case: A 29-year-old woman with no medical comorbidities was admitted following resuscitation from out-of-hospital cardiac arrest with hyperpyrexia, encephalopathy, sinus tachycardia, metabolic acidosis, and ketonaemia (4.0 mmol/l). Investigations showed glucose 20 mmol/l, HbA1c 95 mmol/mol, TSH < 0.01 mIU/l, FT4 37 pmol/l, FT3 16.6 pmol/l, and TRAb 73 U/l (<3.3), consistent with concurrent diabetic ketoacidosis and Graves’ thyrotoxicosis. Thyroid storm was the clinical diagnosis and the Burch-Wartofsky score 90, consistent with thyroid storm (clinical diagnosis). Echocardiography revealed severe biventricular failure (LVEF ≈ 30 %). Despite circulatory support, she developed refractory cardiogenic shock requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Treatment included propylthiouracil 250 mg TDS, Lugol’s iodine 5 drops TDS, and hydrocortisone 100 mg QDS, alongside insulin infusion and supportive care. Over nine days, thyroid hormones normalised; ECMO was weaned with recovery of LVEF to 50–55 %. Islet autoantibodies (GAD, IA-2, ZnT8 > 2000 U/mL) confirmed autoimmune T1DM, establishing the diagnosis of APS-3A. Therapy was transitioned to carbimazole 15 mg BD with a block-and-replace regimen once biochemically hypothyroid. The patient continues to recover and was discharged for rehabilitation.

Discussion: This case illustrates the rare coexistence of thyroid storm and DKA as simultaneous features of APS-3A, culminating in thyrotoxic cardiomyopathy necessitating temporary mechanical support. The clinical severity may exceed biochemical derangement; aggressive and early support is required in thyroid storm and early ECMO as a bridge to recovery can be lifesaving.

Conclusion: Severe presentations of endocrine emergencies can include simultaneous thyroid storm and DKA (each due to autoimmune disease APS-type 3A). In severe cardiorespiratory failure ECMO can be successfully employed to allow endocrine management leading to recovery.