Late-onset Type 1 Diabetes Mellitus in an Elderly Japanese Woman with Single Positive Insulinoma-associated Tyrosine Phosphatase-like Protein-2 (IA-2) Antibody

Abstract

A 79-year-old Japanese old woman hospitalized to assess elevated plasma glucose of 499 mg/dl, HbA₁c 6.0%, and positive urine ketone bodies on January 13,2006, had a urinary C peptide concentration of 11.3 μg/day, indicating decreasing insulin secretion. Although antiglutamic acid dehydrogenase (GAD) antibody was negative, she was suspected to have “fulminant type 1 diabetes” due to the rapid onset. She was also diagnosed with autoimmune-related type 1 diabetes mellitus due to high IA-2 antibody (27U/ml). She was treated with insulin during hospitalization. We consider this worth reporting, because very few cases of senile onset type 1 diabetes mellitus are positive for IA-2 antibody.