[Insulin autoimmune syndrome : A rare, but important differential diagnosis of hypoglycemia].

A 69-year-old female patient was referred to the Medical University of Hanover for further diagnostic evaluation of recurrent severe hypoglycemia. The patient had previously been started on clopidogrel after arterial stenting for peripheral arterial obstructive disease (PAOD). The presence of an insulinoma and paraneoplastic syndrome was excluded. Increased serum insulin and insulin autoantibodies levels were confirmed, despite normal to low blood sugar levels. An insulin autoimmune syndrome was diagnosed, most likely induced by the prior intake of clopidogrel. Treatment with immunoadsorption was initiated, achieving a significant reduction in hypoglycemic events and a lasting response to treatment over 3 months.