Abstract
This 83 year-old male was admitted in August 1982 because of fugue and stupor from midnight to early morning beginning ten days earlier. After admission, hypoglycemia was diagnosed, and suffering from repeated hypoglycemic attacks. A 24-hour plasma glucose profile showed both fasting hypoglycemia and postprandial hyperglycemia, and a 50 g glucose tolerance test showed slight impairment. Simultaneous determinations of fasting serum Immuno-Reactive Insulin (IRI) and serum C-peptide-like Immunoreactivity (CPR) showed extremely elevated values (the former: 6657-13130 itU/ml, the latter: 62.0ng/ ml). Total insulin, free insulin and 1251-insulin binding rate were >770 pU/mi, 52 pU/m/ and 72%, respectively. Major part of antiinsulin antibody belonged to IgG class of kappa light chains. No evidence that he had been treated with such therapeutic agents as methimazol, thiopronin, any kind of ACE inhibitors, or used insulin was obtained. Since hypoglycemic symptoms at night gradually ameriorated without specific treatment, patient was discharged and regularly followed up. Plasma levels of IRI one year and six years after his first hospitalization significantly decreased to 325 μU/ml and 44 μU/ml, respectively, and so hypoglycemia was not occurred during the follow up. HLA types were positive for Loci All, Bw52, 62, Cw4 and DR4.
One hundred and ten cases of Insulin Autoimmune Syndrome (IAIS) were reported in Japan during the period from 1970 to 1984, and this case is recognized as the oldest.
As yet, however, the causes of IAIS have not been determined, and the key to their elucidation depends on accumulating as many cases as possible and additional and more advanced investigations.
