Medical Nutrition Therapy Is Effective in the Management of Hypoglycemia Caused by Insulin Antibodies: A Case Report and Literature Review

Insulin autoimmune syndrome induced by omeprazole in an Asian Male with HLA-DRB1*0406 Subtype: A case report

Insulin autoimmune syndrome (IAS) is characterized by hyperinsulinemic hypoglycemia and elevated anti-insulin antibodies. While thiol-containing drugs commonly induce IAS, cases induced by proton pump inhibitors are rare. We report a case of IAS induced by omeprazole in a 27-year-old Chinese man with the HLA-DRB1*0406 subtype. This patient presented with Whipple's triad after taking omeprazole without concurrent insulin use. The mixed-meal tolerance test (MMTT) and insulin-C-peptide release tests revealed a rapid surge in insulin levels within one hour, with a non-significant increase in C-peptide and a significant rise in insulin after precipitation. Further examination revealed high-titer positive insulin autoantibodies, leading to a diagnosis of insulin autoimmune syndrome (IAS). Symptoms resolved upon discontinuation of omeprazole and adherence to dietary recommendations, with insulin autoantibody levels decreasing after a 6-month follow-up. This case highlights omeprazole's potential to induce IAS, underscoring the need for vigilance due to widespread use of proton pump inhibitor.

Persistent Insulin Autoimmune Syndrome in a Caucasian Male in the Absence of Triggers

Insulin autoimmune syndrome (IAS) or Hirata disease is a rare condition presenting as recurrent hypoglycemia, and associated with elevated insulin levels in the presence of insulin autoantibodies (IAAs) in patients who were never exposed to exogenous insulin and with no evidence of pancreatic abnormalities. IAS is much more frequent in East Asians, especially the Japanese population, compared to the lower incidence in Caucasians. However, it can be associated with other autoimmune diseases or drug use like methimazole and alpha-lipoic acid (ALA). We report a case of a 47-year-old Caucasian male presenting with a 12-month history of worsening episodes of fasting and post-prandial hypoglycemia associated with symptoms of dizziness, tremors, palpitations, and unconsciousness associated with hypoglycemia. Symptoms resolved with the administration of carbohydrate-containing foods, establishing Whipple's triad. At an outside facility, he had initial labs that showed elevated insulin levels (141 µU/ml) with normal glucose, C-peptide, and proinsulin levels, but there was no availability of an IAA lab assay. Given his symptoms, severity, and frequency of hypoglycemia, he was admitted to the hospital for a 72-hour fast, which showed the lowest glucose level of 64 mg/dl with inappropriately high insulin of 22.2 µU/ml, low C-peptide of 0.57 ng/ml, and undetectable proinsulin of <1.6 pmol/L, but with IAA being >50 U/ml (0.0-0.4 U/ml). He was treated with intensive dietary counseling with a low-carbohydrate diet and prednisone 20 mg twice daily initially. Additionally, he could not tolerate octreotide, diazoxide, and acarbose due to side effects. He is currently on prednisone 10 mg daily and nifedipine with no further hypoglycemic episodes, but still has a high IAA of >50 U/ml and serum insulin levels of 70-112 µU/ml. Our case highlights the importance of recognizing hypoglycemia and checking for IAA levels as first-line diagnostic tests, in the absence of which there could be a delay in diagnosis and leading to unnecessary lab and imaging testing. Our case is unique since it happened in a Caucasian without any prior exposure to a triggering factor and has not undergone self-remission yet, which happens in most of IAS cases.

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 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.

Hypoglycemia Caused by Exogenous Insulin Antibody Syndrome: A Large Single-Center Case Series From China

CONTEXT

Exogenous insulin antibody syndrome (EIAS) can lead to unexpected and potentially life-threatening recurrent hypoglycemia.

OBJECTIVE

We aimed to better define autoimmune hypoglycemia caused by EIAS in patients with diabetes and shed light on the improvements in the identification and intervention for this rare but possibly life-threatening condition.

METHODS

We summarized the clinical characteristics of autoimmune hypoglycemia caused by EIAS in 23 patients with diabetes. Furthermore, we performed human leukocyte antigen (HLA) genotyping of 10 patients.

RESULTS

We identified a high frequency of autoimmune comorbidities (21.7%), food or drug allergy (48%), insulin allergy (30%), lipodystrophy at the insulin injection sites (22%), and antinuclear antibodies (25%) in the patients. Alternation between hyperglycemia and hypoglycemia was observed in more than 90% of the patients. Most patients showed a high insulin autoantibody titer (>90%) and inappropriately increased insulin concentration (insulin/C-peptide molar ratio >7, >85%). We detected similar frequencies of DRB1*0405-DQB1*0401 and DRB1*0901-DQB1*0303 compared with previously reported frequencies in type 1 diabetes, and a lower frequency of DRB1*0406 compared with insulin autoimmune syndrome. The spontaneous remission rate exceeded 70%.

CONCLUSION

Predisposing factors for autoimmune hypoglycemia caused by EIAS include a strong autoimmune background. Susceptible HLA genotypes for type 1 diabetes or insulin autoimmune syndrome might not explain susceptibility to this condition. Additionally, insulin autoantibodies and the insulin/C-peptide molar ratio are reliable screening options. The prognosis for this condition is favorable. Monitoring of insulin and insulin autoantibodies may contribute to treatment effectiveness.

Type 1 diabetes complicated with cyclic vomiting syndrome and exogenous insulin antibody syndrome: A case report

Every fifth individual with type 1 diabetes (T1D) suffers from an additional autoimmune disorder due to shared genetic factors and dysregulated immunity. Here we report an extremely rare case of T1D complicated with cyclic vomiting and hypoglycaemia. A 27-year-old Chinese woman with 14-year history of T1D was periodically hospitalized for severe vomiting of more than 30 times a day without apparent organic causes. The vomiting developed acutely and remitted spontaneously after 2-3 days, followed with intractable hypoglycaemia for another 3-4 days during the hospitalization. A few weeks after discharge, she was admitted once again with the same symptoms and disease course. Cyclic vomiting syndrome (CVS) was diagnosed according to the Rome IV criteria, a system developed to define the functional gastrointestinal disorders. Dynamic association and disassociation of exogenous insulin and insulin antibodies (IAs) were identified in her blood during hypoglycaemia, leading to the diagnosis of exogenous insulin antibody syndrome (EIAS). Treatment with rituximab to suppress the IAs was associated with a striking amelioration of hypoglycaemia. Unexpectedly, the episodes of cyclic vomiting were also dramatically reduced. In conclusion, we identified the first case with alternating CVS and EIAS in the setting of T1D. Dynamic measurements of free and total insulin are helpful for the diagnosis of EIAS. CVS is likely to be a latent autoimmune disorder considering the good response to rituximab treatment.

Exogenous insulin antibody syndrome treated with plasma exchange after an incomplete response to immunosuppressive therapy

A 43‐year‐old man with a 23‐year history of type II diabetes presented with uncontrolled hyperglycemia with frequent episodes of ketoacidosis. He was diagnosed with exogenous insulin antibody syndrome, and received high‐dose methylprednisolone to treat insulin resistance. Ketoacidosis relapsed 2 years later, and the patient showed an incomplete response to glucocorticoids. We decided to administer therapeutic plasma exchange, which resulted in rapid lowering of the daily insulin requirement and improved glycemic control.

Analysis of the clinical characteristics of insulin autoimmune syndrome induced by exogenous insulin in diabetic patients

BACKGROUND

The exact incidence, clinical features and uniform diagnostic criteria of exogenous insulin autoimmune syndrome (EIAS) are still unclear. The purpose of this study is to explore the clinical characteristics of EIAS and to provide a structural approach for clinical diagnosis, treatment and prevention.

METHODS

The literature on EIAS in Chinese and English from 1970 to 2020 was collected for retrospective analysis.

RESULTS

A total of 122 patients (33 males and 73 females) were included in the study with a median age of 67 years (range 14-86) and a median HbA1c of 7.7%. EIAS mainly occurred in type 2 diabetes mellitus patients using premixed insulin. Symptoms manifested were hypoglycemia in 86.54%, recurrent episodes of symptomatic hypoglycemia in 35.58%, nocturnal hypoglycemia along with daytime hyperglycemia in 21.15% and recurrent hypoglycemia after discontinued insulin in 64.43%. The onset of symptoms occurred at night, in the early morning or during fasting, ranging from a few days to 78 months after the administration of insulin. The mean blood glucose level during the hypoglycemic phase was 2.21 mmol/L (range 1-3.4), and the serum insulin levels were mainly ≥ 100 U/mL and were associated with low C-peptide levels (≤ 10 ng/ml). Insulin autoantibodies (IAAs) were positive in all EIAS patients. The 75-g extended oral glucose tolerance test (OGTT) mainly showed a diabetic curve. Pancreatic imaging was unremarkable. Withdrawal of insulin alone or combination of oral hypoglycemic agents or replacement of insulin formulations or with corticosteroid treatment eliminated hypoglycemia in a few days to 3 months. IAA turned negative in 6 months (median, range 1-12). No hypoglycemia episodes were observed at a median follow-up of 6 months (range 0.5-60).

CONCLUSIONS

EIAS is an autoimmune disease caused by insulin-binding antibodies in susceptible subjects. Insulin antibodies change glucose dynamics and could increase the incidence of hypoglycemic episodes. Detection of insulin antibodies is the diagnostic test. Changing therapeutic modalities reduced the incidence of hypoglycemic episodes.

Therapeutic plasma exchange for exogenous insulin antibody syndrome in combined variable immunodeficiency: a case report

A 32-year-old male with type I diabetes presented with profound hypoglycemia due to exogenous insulin antibody syndrome in the setting of newly-diagnosed common variable immunodeficiency. Immunomodulatory therapy was not initially effective, but after the initiation of plasma exchange hypoglycemia resolved, and glucose lability improved.

Insulin autoimmune syndrome: from diagnosis to clinical management

Autoimmune forms of hypoglycemia are a rare cause of low blood sugar levels among Caucasians, and often go misdiagnosed, exposing patients to lengthy series of pointless, potentially harmful and expensive tests. There are two types of autoimmune hypoglycemia. One is insulin autoimmune syndrome (IAS), which is characterized by hyperinsulinemic hypoglycemia, elevated insulin autoantibody (IAA) titers, no prior exposure to exogenous insulin, and no of pathological abnormalities of the pancreatic islets. This condition is also known as "Hirata's disease". The other is type B insulin resistance syndrome (TBIRS), a rare autoimmune disorder resulting in a broad array of abnormalities in glucose homeostasis-from hypoglycemia to extremely insulin-resistant hyperglycemia-caused by the presence of insulin receptor autoantibodies (IRAbs). This review focuses on these two syndromes, describing their epidemiology, possible genetic background, clinical presentation, pathophysiology, diagnosis and treatment.

Exogenous insulin antibody syndrome (EIAS): a clinical syndrome associated with insulin antibodies induced by exogenous insulin in diabetic patients

Insulin has been used for diabetes therapy and has achieved significant therapeutic effect. In recent years, the use of purified and recombinant human insulin preparations has markedly reduced, but not completely suppressed, the incidence of insulin antibodies (IAs). IAs induced by exogenous insulin in diabetic patients is associated with clinical events, which is named exogenous insulin antibody syndrome (EIAS). The present review is based on our research and summarizes the characterization of IAs, the factors affecting IA development, the clinical significance of IAs and the treatments for EIAS.