Abstract
In Japan, since 1970, fourteen patients have been reported who suffered from a new type of hypoglycemia, called insulin autoimmune syndrome, associated with insulin antibodies without any immunization using insulin preparations. One of characteristics of this syndrome is that remission of the disease occurs pontaneously.
A 70-year-old Japanese man was admitted to the Saiseikai Imabari Hospital on February 12, 1975 because he became unconscious every morning after February 5. Each attack was treated with intravenous injection of glucose. Attacks occurred in the early morning of February 13 and 14. Blood glucose during the two attacks was 40 mg/100ml and 24 mg/100ml respectively. On February 15 the attacks disappeared spontaneously, and hypoglycemic attacks occurred only once in ten days. Immunoreactive insulin (IRI) extracted with acid ethanol was 9020μU/ml, and C-peptide immunoreactivity (CPR) was 36 ng/ml in serum obtained during the attack of February 14, 1975. Major portions of the IRI and CPR were extracted from serum IgG which was precipitated with anti-human IgG antiserum.
By radioimmunoelectrophoresis, specific precipitation method and Christiansen's method, insulinbinding antibodies of the patient were found only in IgG. Light chains of the insulinbinding globulins were mainly of the kappa type, as compared with diabetics treated with insulin in whom the lambda type could not be disregarded besides the kappa type. The patient's serum showed only non-specific binding to, 125I-porcine proinsulin, although diabetics treated with insulin had specific antibodies to porcine proinsulin in the serum.
The diagnosis of insulin autoimmune syndrome was made on this patient who showed rapid and spontaneous improvement after the attacks of spontanous hypoglycemia.
