A case of insulin autoimmune syndrome / 대한내과학회지

Insulin autoimmune syndrome is an uncommon cause of hypoglycemia. According to the type of antibody, it can be classified as caused by insulin or insulin receptor autoantibodies. Generally, insulin autoimmune syndrome develops following exposure to exogenous insulin or sulfhydryl medications, although insulin or insulin receptor antibody may also occur spontaneously. We treated a 54-year-old woman who developed spontaneous hypoglycemia. The patient had repeated hypoglycemia despite the infusion of dextrose solution. Her serum insulin, c-peptide, and insulin autoantibody were elevated, even during the hypoglycemic periods. Insulin receptor autoantibody and HLA-cw4/B62/DR4 were positive. After steroid and diazoxide treatment, the hypoglycemic symptoms improved gradually. No further hypoglycemic episodes occurred after tapering the medication over 1 year. We present a case of insulin autoimmune syndrome with positive insulin and insulin receptor autoantibodies.

A Case of Autoimmune Hypoglycemia Complicated with Diabetic Ketoacidosis

Autoimmune hypoglycemia is characterized by hyperinsulinemia, fasting hypoglycemia, and the presence of insulin auto- antibodies without previous exposure to exogenous insulin. We experienced a case of autoimmune hypoglycemia without diabetes mellitus or any evidence of insulinoma. The insulin auto-antibody and insulin receptor auto-antibody were present. We diagnosed the patient as having autoimmune hypoglycemia and treated with glucocorticoid. After treatment, the hypoglycemic symptoms were resolved. However, four months later, the patient was readmitted with transient diabetic ketoacidosis. After recovery, he showed no signs of diabetes mellitus. We believe that insulin auto-antibodies may play a role in autoimmune hypoglycemia and diabetic ketoacidosis, but its role and mechanism are not precisely known. Further studies are needed to define the action mechanisms and the functions of insulin auto-antibodies: here we present case with a relevant literature.