Clinical Analysis Of Three Patients Of Insulin Autoimmune Syndrome And Literature Review

Objective: This study aims to analysis the clinical features of three cases of Insulin autoimmune syndrome(IAS)to in order to improve the reorganization and levels of diagnosis and treatments of the disease,and reduce misdiagnosis and mistreatment of the disease in the clinical practice.Methods:The clinical features of three IAS patients who diagnosed and treated in our Hospital from March 2011 to August 2015,were retrospectively collected,including medical history,physical examination,diagnosis,therapy and prognosis,and those clinical characteristics were analyzed in combination with literature review.Results:1.3 cases of IAS patients reported in this study,including 2 females and 1 male;age was between 59 and 63 years old.2.Of the 3 cases 2 patients had suspicious history of using sulfur/sulfydryl drugs and autoimmune disorders,including a case of taking "methimazole" many times for "hyperthyroidism" recurrence,and a case of clopidogrel for antiplatelet treatment over one year with a small high immunoglobulin G,while the other one had no definite cause.3.3 cases of IAS showed recurrent severe spontaneous hypoglycemia as the first symptom,there was no regular pattern of the onset time of hypoglycemia,and swing as hyperglycemia and hypoglycemia.4.Insulin levels and insulin release indices were significantly elevated in 3 IAS patients when hypoglycemia was occured;C-peptide level was not obvious elevated,blood glucose<2.8mmol/L,the plasma insulin>156uIU/mL,insulin release index>3.61.5.Extended OGTT of 2 patients in 3 cases showed that diabetes mellitus or impaired glucose tolerance after meal,all induced hypoglycemia lately;1 case of total C-peptide levels were increased and showed "separation phenomenon" compared with insulin in inducing hypoglycemia.6.The serum insulin autoantibody were all positive.7.There were any abnormal pancreas of 3 cases.8.After treatments including the drug which might induce IAS was not employed and adjustment of dietary structure,or short-term glucocorticoids were used,the symptoms of hypoglycemia did not occur again.Conclusion:Non-diabetic patients,who have not used exogenous insulin,with repeatedly irregularly severe hypoglycemia and swings as hypoglycemia and hyperglycemia,occur hypoglycemia with significantly increased level of serum insulin,it need to be alert to the possibly of insulin autoimmune syndrome.It is necessary to oral glucose tolerance test,if the test can induce hypoglycemia and the increased insulin levels is significantly higher than the increased C-peptide,it should consider the more possibility of insulin autoimmune syndrome.It need to should improve the insulin autoantibody test and pancreatic imaging examination,if the insulin autoantibody is positive and excluding insulinoma by imaging,it can diagnose insulin autoimmune syndrome.The disease is generally good prognosis,the antibody can transform negative in short-term.After 3 months treatment,if possible,insulin autoantibody?insulin level and C-peptide level need to be test.