A case of autoimmune insulin syndrome / 대한내과학회지

ABSTRACT

Autoimmune insulin syndrome is characterized by a combination of fasting hypoglycemia, high total serum insulin concentrations, and the presence of autoantibodies to the native human insulin in serum. A healthy 69-year-old man developed spontaneous hypoglycemia after being given some medications for the common cold. His laboratory finding shows endogenous hyperinsulinism. Therefore, an insulinoma was suspected but the imaging study shows no mass lesion in the pancreas and the anti-insulin antibody titer was high(>100U/mL). He had no specific medication history except for a treatment of a current upper respiratory infection (URI). Among the URI medication, it was found that N-acetylcysteine contains a sulfhydryl group and could induce autoimmunization. The patient was treated with corticosteroid for 3 months. His anti-insulin antibody titer had decreased to normal level and has not shown any hypoglycemic episodes for more than one and a half years. We present this case with a review of relevant literature.