Early Remission of Type B Insulin Resistance Syndrome Achieved by Glucocorticoid-based Immunosuppressive Therapy and Visualized by Intermittently Scanned Continuous Glucose Monitoring

Type B insulin resistance syndrome (TBIRS) is an extremely rare autoimmune disorder characterized by severe insulin resistance and/or hypoglycemia caused by autoantibodies against the insulin receptor (IRAb). We report the case of a 52-year-old woman who presented with weight loss and severe hyperglycemia resistant to high-dose insulin therapy. Markedly elevated IRAb levels confirmed the diagnosis of TBIRS. Glucocorticoid-based immunosuppressive therapy with cyclosporine rapidly improved glycemic control, and clinical remission was achieved approximately 40 days after treatment initiation. Intermittently scanned continuous glucose monitoring enabled the visualization of the transition from extreme insulin resistance to near-normoglycemia and helped avoid severe hypoglycemia during the patient's antibody decline period.