ESPE Abstracts

Background: Islet autoantibodies such as Glutamic Acid Decarboxylase (GAD), Islet antigen-2 (IA-2), Zinc Transporter 8 (ZnT8), and Insulin autoantibody (IAA) are known to be detected at higher frequencies in pediatric patients clinically diagnosed with type 2 diabetes than in adults. Therefore, it is crucial to evaluate them for accurate diagnosis, prognosis, and treatment direction. However, guidelines for when to re-evaluate patients with negative islet autoantibody results have not been established yet.

Case report: A 12-year-old boy was referred to our hospital with suspicion of metabolic syndrome related to severe obesity, hypertension, hyperglycemia, and elevated liver enzymes from a local clinic. His height was 163.1 cm, weight 81.9 kg, body mass index (BMI) 21.4 kg/m2 (BMI z-score 3.08), and blood pressure 125/89 mmHg. No glycosuria, proteinuria, or ketonuria was found in the urinalysis performed at our hospital. He showed increased AST/ALT levels at 98/154 u/L, HbA1c 7.8%, c-peptide 9.49 ng/mL (random glucose 146 mg/dL), acanthosis nigricans, HOMA2B 169.8%, and HOMA2IR 8.00, leading to a diagnosis of type 2 diabetes with insulin resistance as the main pathological mechanism. Initial treatment with metformin and basal insulin was started for induction. At the time of the initial diagnosis, islet autoantibodies, including GAD antibody, islet cell antibody, and anti-insulin antibody, were all negative. During the 3-year follow-up, despite increasing the basal insulin dose to 1 IU/kg, his HbA1c remained poorly controlled at 8.4% and c-peptide decreased to 2.28 ng/mL (glucose 173 mg/dL). HOMA2B value decreased to 41.3%, and HOMA2IR was 2.06. The decision was made to switch to insulin multiple daily injections, and a retest of GAD antibody revealed a seroconversion to 2.4 U/ML (reference range <1.0), confirming a diagnosis of latent autoimmune diabetes in youth (LADY).

Conclusion: The prevalence of LADY in pediatric patients has not been accurately determined. When the clinical course differs from typical pediatric type 2 diabetes, evaluating for seroconversion to diagnose LADY may be necessary, even if initial islet autoantibody results are negative.