Histological changes of the pancreas in an elderly diabetic patient positive for GAD antibody

We examined the histological changes of the pancreas in a 75-year-old diabetic woman who was treated with sulphonylurea for 10 years and required insulin treatment for the subsequant 10 years. She was positive for antiglutamic acid decarboxylase antibody (GAD Ab) 20 years after the diagnosis of diabetes. Her autopsied pancreas revealed disfigured islets and no beta cells. These changes were indistinguishable from those of the long-sustained type 1 diabetes mellitus, and insulitis was not found. This case suggests that diabetic patients positive for the GAD Ab, even if oral hypoglycemic agents are effective, may develop complete beta cell destruction over a long period.