Insulin Autoimmune Syndrome (Hirata's disease): severe hypoglycemic episodes in Graves' hyperthyroidism patient treated with methimazole.

Insulin Autoimmune Syndrome (IAS) or Hirata’s disease is characterized by severe hypoglycemic episodes, a high level of immunoreactive insulin, and a high titer of insulin autoantibody in a person who has never received exogenous insulin. It is noted that IAS has a strong genetic predisposition and the majority of the IAS cases were reported from Japan, where it is the third leading cause of hypoglycemia. It is also known that some drugs with sulphydryl groups in their chemical structures can induce the formation of insulin autoantibodies in predisposed individuals, and Graves’ patient who possesses Bw62/Cw4/DR4 carrying DRB1*0406 maybe at risk of developing IAS when methimazole is administered. The following is the first IAS (Hirata’s disease) case reported from Indonesia, in a patient with Graves’ disease who was treated with methimazole.