Case Report
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Mar 26, 2024; 12(9): 1691-1697
Published online Mar 26, 2024. doi: 10.12998/wjcc.v12.i9.1691
Exogenous insulin autoimmune syndrome: A case report and review of literature
Ling-Ling Xu, Jia-Xin Chen, Jing-Ping Cheng, Ni Luo
Ling-Ling Xu, Jia-Xin Chen, Medical College, School of Medicine, Wuhan University of Science and Technology, Wuhan 430065, Hubei Province, China
Jing-Ping Cheng, Ni Luo, Department of Gerontology, CR & WISCO General Hospital Affiliated to Wuhan University of Science and Technology, Wuhan 430080, Hubei Province, China
Co-first authors: Ling-Ling Xu and Jia-Xin Chen.
Co-corresponding authors: Jing-Ping Cheng and Ni Luo.
Author contributions: Xu LL wrote the manuscript; Chen JX proofread and verified the data in the manuscript; Cheng JP and Luo N screened patients and obtained clinical data and final reviewed the manuscript; All authors have read and approve the final manuscript. Xu LL summarized the data and wrote the first draft. Chen JX proof-collated the data and optimized the manuscript. Both authors have made crucial and indispensable contributions towards the completion of the project and thus qualified as the co-first authors of the paper. Both Cheng JP and Luo N have played important and indispensable roles in data interpretation and manuscript preparation as the co-corresponding authors. Cheng JP conceptualized, designed, and supervised the whole process of the project. Luo N was responsible for data re-analysis and re-interpretation, table drawing and ideas refining. This collaboration between Cheng JP and Luo N is crucial for the publication of this manuscript and other manuscripts still in preparation.
Informed consent statement: Informed written consent was obtained from the patient for publication of this report and any accompanying tables.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Jing-Ping Cheng, Doctor, Chief Doctor, Department of Gerontology, CR & WISCO General Hospital Affiliated to Wuhan University of Science and Technology, No. 29 Metallurgy Avenue, Qingshan District, Wuhan 430080, Hubei Province, China. 404178516@qq.com
Received: January 24, 2024
Peer-review started: January 24, 2024
First decision: January 31, 2024
Revised: February 23, 2024
Accepted: March 6, 2024
Article in press: March 6, 2024
Published online: March 26, 2024
Abstract
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 non-classical 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.

Keywords: Insulin autoimmune syndrome, Type 2 diabetes, Exogenous insulin, Insulin autoantibodies, Hypoglycemia, Case report

Core Tip: Exogenous insulin autoimmune syndrome (EIAS), also known as non-classical insulin autoimmune syndrome, occurs in individuals with type 2 diabetes who use exogenous insulin, resulting in the production of insulin autoantibodies and the subsequent development of hyperinsulinemia. This condition is characterized by significant fluctuations in blood glucose levels and insulin resistance. In patients with type 2 diabetes receiving treatment with oral medications or insulin therapy, episodes of hypoglycemia are often attributed to drug-related causes. Consequently, EIAS tends to be overlooked in clinical practice, particularly among elderly patients. Herein, we report a case of EIAS in an elderly person. Based on an analysis of PubMed cases, it has been observed that the disease tends to be self-limiting with a favorable prognosis.