Hypoglycemia due to antiinsulin receptor antibodies in systemic lupus erythematosus.

An elderly woman with unexplained episodic fasting hypoglycemia was hospitalized for ascites. Evaluation revealed polyserositis, arthritis and immunologic abnormalities that suggested the diagnosis of systemic lupus erythematosus (SLE). Antibodies to insulin receptor with insulin binding inhibitory activity were detected in her serum. Treatment with prednisone was accompanied by resolution of hypoglycemic episodes and disappearance of the antireceptor antibodies. Autoantibody mediated alterations in serum glucose may be included in the growing list of autoimmune phenomena in SLE. Antiinsulin receptor antibodies should be sought in patients with SLE and idiopathic hypoglycemia.