Exogenous insulin autoimmune syndrome:A case report and review of literature

BACKGROUND Insulin autoimmune syndrome(IAS)is a severe manifestation of spontaneous hypoglycemia.It is characterized by elevated levels of immune-reactive insulin and highly potent insulin autoantibodies(IAAs),which are induced by endogenous insulin circulating in the bloodstream.It is distinguished by recurring instances of spontaneous hypoglycemia,the presence of IAA within the body,a substantial elevation in serum insulin levels,and an absence of prior exogenous insulin administration.Nevertheless,recent studies show that both conventional insulin and its analogs can induce IAS episodes,giving rise to the notion of nonclassical IAS.Therefore,more attention should be paid to these diseases.CASE SUMMARY In this case report,we present a rare case of non-classical IAS in an 83-year-old male patient who present with symptoms of a psychiatric disorder.Upon symptom onset,the patient exhibited Whipple's triad(including hypoglycemia,blood glucose level less than 2.8 mmol/L during onset,and rapid relief of hypoglycemic symptoms after glucose administration).Concurrently,his serum insulin level was significantly elevated,which contradicted his C-peptide levels.After a comprehensive examination,the patient was diagnosed with exogenous insulin autoimmune syndrome.Considering that the patient had type 2 diabetes mellitus and a history of exogenous insulin use before disease onset,it was presumed that non classical IAS was induced by this condition.The PubMed database was used to search for previous cases of IAS and non-classical IAS to analyze their characteristics and treatment approaches.CONCLUSION The occurrence of non-classical IAS is associated with exogenous insulin or its analogs,as well as with sulfhydryl drugs.Symptoms can be effectively alleviated through the discontinuation of relevant medications,administration of hormones or immunosuppressants,plasma exchange,and lifestyle adjustments.

Overcoming of insulin autoantibody mediated insulin resistance in a Chinese elderly patient with multi-organ dysfunction by withdrawal of insulin injection:a case report and review of literature

Insulin autoantibody (IAA) mediated insulin resistance (AMIR) is very rare in human insulin era.Here we report a typical case of a 90-year-old Chinese man who suffered from heart and renal dysfunction,lung infection and very poor blood glucose control,and meanwhile injected with higher than 200 U human insulin for his diabetes.His IAA was posi-tive with high affinity to insulin,as insulin antigen-antibody binding rate was 52% in vitro.Serum insulin level and the binding rate decreased dramatically with cession of insulin injection; also blood glucose profile restored to response to pre-vious dose insulin injection and remained during follow-up.Both the reason for the IAA formation and the solution to the AMIR were discussed in detail.