Autoimmune thrombocytopenia and primary biliary cirrhosis with hypoglycemia and insulin receptor autoantibodies. A case report.

A 43-year-old woman with spontaneous episodes of neuroglycopenic hypoglycemia was found to have immune-mediated thrombocytopenic purpura and primary biliary cirrhosis. Hypoglycemia along with hyperinsulinemia suggested insulinoma. Serum c-peptide levels were disproportionately low, raising the possibility of factitious hypoglycemia. The patient's plasma contained circulating insulin receptor autoantibodies, thought to cause hypoglycemia by their insulin-like actions. With prednisone therapy, her other autoimmune features improved, and the hypoglycemia eventually resolved. Hypoglycemia mediated by insulin receptor autoantibodies should be considered in patients with fasting hypoglycemia and features suggesting an underlying autoimmune disorder before pursuing more invasive procedures. High-dose steroids may be life-saving in this disorder.