Drug-induced insulin autoimmune syndrome

Exogenous Insulin Antibody Syndrome (EIAS) Presenting in an Elderly, Long-Term Patient with Type 1 Diabetes Mellitus that Resolved with Low-Cost Outpatient Therapy with Mycophenolate Mofetil and Regular Insulin by Pump

Exogenous insulin antibody syndrome (EIAS) has until recently been a rarely described complication of exogenous insulin therapy. EIAS results not only in hyperglycemia, but also in hypoglycemia and occasionally in ketoacidosis (DKA). The incidence of EIAS is increasing probably due to an overall increase in autoimmunity associated with the coronavirus disease 2019 (Covid-19) epidemic resulting in increasing binding of insulin by antibodies. Herein, we describe a case of EIAS occurring in an elderly patient with longstanding type 1 diabetes mellitus (T1DM) who had progressive loss of glycemic control. It responded positively, as we have previously described, to oral mycophenolate mofetil and the use of soluble regular insulin delivered by continuous subcutaneous insulin infusion (CSII). Therefore, EIAS is an increasingly frequent cause of hyperglycemia with and without DKA, and hypoglycemia in subjects with T1DM. Once diagnosed, they can be treated with mycophenolate mofetil and soluble insulin in an outpatient setting, which will decrease the rate of hospitalization and lower the expense of therapy.

A clinical case of insulin autoimmune syndrome with monoclonal gammopathy of uncertain significance; complexity in management

Insulin autoimmune syndrome (IAS) is a rare cause of spontaneous hypoglycaemia. We discuss a 91-year-old Caucasian lady who presented with syncope and episodic adrenergic and neuroglycopenic symptoms. Despite significantly elevated insulin, C-peptide, and proinsulin levels with the presence of anti-insulin antibodies, a pancreatic mass was not identified. Serum immunoelectrophoresis demonstrated monoclonal gammopathy of undetermined significance (MGUS). Treatment involved high-dose steroids, diazoxide, corn starch and acarbose, however the patient passed away four months later due to worsening co-morbidities. The management of IAS in the setting of MGUS is challenging.

How should we differentiate hypoglycaemia in non-diabetic patients?

Hypoglycaemic syndromes are rare in apparently healthy individuals and their diagnosis can be a difficult challenge for clinicians as there are no shared guidelines that suggest how to approach patients with a suspect hypoglycaemic disorder. Since hypoglycaemia symptoms are common and nonspecific, it's necessary to document the Whipple Triad (signs and/or symptoms compatible with hypoglycaemia; relief of symptoms following glucose administration; low plasma glucose levels) before starting any procedure. Once the triad is documented, a meticulous anamnesis and laboratory tests (blood glucose, insulin, proinsulin, C-peptide, β-hydroxybutyrate and anti-insulin antibodies) should be performed. Results can guide the physician towards further specific tests, concerning the suspected disease. In this review, we consider all current causes of hypoglycaemia, including rare diseases such as nesidioblastosis and Hirata's syndrome, describe appropriate tests for diagnosis and suggest strategies to differentiate hypoglycaemia aetiology.

Drug-induced hyperinsulinemic hypoglycemia: An update on pathophysiology and treatment

The initial step for the differential diagnosis of hypoglycemia is to determine whether it is hyperinsulinemic or non hyperinsulinemic. Existing literature discusses drug-related hypoglycemia, but it misses a focus on drug-induced hyperinsulinemic hypoglycemia (DHH). Here we reviewed the association existing between drugs and hyperinsulinemic hypoglycemia. We primarily selected on the main electronic databases (MEDLINE, EMBASE, Web of Science, and SCOPUS) the reviews on drug-induced hypoglycemia. Among the drugs listed in the reviews, we selected the ones linked to an increase in insulin secretion. For the drugs missing a clear association with insulin secretion, we investigated the putative mechanism underlying hypoglycemia referring to the original papers. Our review provides a list of the most common agents associated with hyperinsulinemic hypoglycemia (HH), in order to facilitate both the recognition and the prevention of DHH. We also collected data about the responsiveness of DHH to diazoxide or octreotide.

Clopidogrel as a Distinctive Cause of Insulin Autoimmune Syndrome: A Systematic Case Review

The sulfhydryl group of clopidogrel metabolite could induce insulin autoimmune syndrome (IAS) with hypoglycemia as the major symptom. For patients with cardiovascular disease taking clopidogrel for vascular protection, this adverse event hypoglycemia increases the risk of cardiovascular events. However, discontinuing clopidogrel leaves patients without appropriate antiplatelet therapy. Treating IAS with glucocorticoids is also risky for these patients' primary cardiovascular diseases. Early recognition and appropriate treatment of clopidogrel-induced IAS (CIAS) would be beneficial for patients. This research aimed to discover the clinical features and investigate optimal therapeutic management of CIAS. We systematically searched for cases of CIAS in PubMed and Embase and performed data mining in Food and Drug Administration Adverse Event Reporting System (FAERS). In the CIAS series, clinical features were summarized and compared to 287 IAS cases, including demographic information, HLA alleles, onset, and symptoms. The therapeutic effect of glucocorticoids was compared between the receiving group and the not-receiving group. The possibilities of common antiplatelet drugs to induce hypoglycemia/IAS were investigated with chemical structure and FAERS reports. A CIAS series of 51 patients was established. CIAS had an onset age of 74.8±8.6 years old, 92.2% male, and a balanced proportion of East Asians and non-East Asians. Confusion occurred more frequently in CIAS than in IAS from various causes, while the other symptoms and hypoglycemia types were similar. The recovery time was approximately the same whether using glucocorticoids/immunotherapy in CIAS or not. Among common antiplatelet drugs, ticagrelor and rivaroxaban were unlikely to induce hypoglycemia/IAS. Clopidogrel is a distinctive cause of IAS featuring an elderly male presenting confusion as the symptom of hypoglycemia. Glucocorticoids/immunotherapy might not be necessary for the long-term recovery of CIAS. To balance the risks of hypoglycemia and cardiovascular events, substituting clopidogrel with ticagrelor and rivaroxaban might be considered.

A disproportionality analysis of the adverse effect profiles of methimazole and propylthiouracil in patients with hyperthyroidism using the Japanese Adverse Drug Event Report Database

BACKGROUND

Antithyroid drugs (ATDs) are frequently used to achieve euthyroidism in patients with hyperthyroidism. ATDs cause characteristic common and rare adverse events; however, comprehensive comparisons between methimazole (MMI) and propylthiouracil (PTU) in terms of adverse events are limited.

METHODS

In this study, we thoroughly explored adverse events in association with MMI and PTU use with a disproportionality analysis using the Japanese Adverse Drug Event Report (JADER) database and evaluated the prevalence of MMI and PTU prescriptions using the National Database of Health Insurance Claims and Specific Health Checkups (NDB) Open Data Japan. We analyzed 3271 cases of MMI use and 1029 cases of PTU use with respect to 9789 preferred terms (PTs) for adverse events registered in the JADER database by calculating and comparing reporting odds ratios (RORs).

RESULTS

We found that 8 PTs, including agranulocytosis (p < 0.0001, 4.01-fold), aplasia cutis congenita (p < 0.0001, 123.22-fold), and exomphalos (p = 0.0002, 22.17-fold), demonstrated significantly higher RORs (more than 4-fold) for MMI use than for PTU use. Nineteen PTs, including anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (p < 0.0001, 29.84), rapidly progressive glomerulonephritis (p < 0.0001, 6.44), and pulmonary alveolar hemorrhage (p < 0.0001, 7.77), had RORs for PTU use more than four times those for MMI use. NDB Open Data Japan showed more frequent PTU prescriptions than MMI prescriptions for women of reproductive age.

CONCLUSIONS

This large-scale study confirmed that a variety of congenital malformations were identified as having significantly high RORs for MMI use, while diseases related to ANCA-associated vasculitis were specific to PTU.

Hypoglycemia as a potential risk for patients taking clopidogrel: A systematic review and meta-analysis

BACKGROUND

Clopidogrel is a cornerstone antiplatelet drug used in cardiovascular, cerebrovascular, and peripheral artery diseases. The sulfhydryl group of clopidogrel metabolite could induce insulin autoimmune syndrome (IAS) with hypoglycemia as the major symptom. Discontinuing clopidogrel and substituting it with ticagrelor has been revealed as an effective treatment in previous studies. Since hypoglycemia serves as a risk factor for cardiovascular and cerebrovascular events, we aimed to determine the association between hypoglycemia/IAS and clopidogrel and to investigate whether clopidogrel is a modifiable and causal risk factor of hypoglycemia/IAS.

METHODS

MEDLINE, Embase, Cochrane databases, and clinical trial registries were searched for randomized controlled trials (RCTs) of clopidogrel from inception to 28 February 2022. RCTs comparing clopidogrel with placebo or other antiplatelet drugs were eligible if meeting the inclusion criteria: 1) clopidogrel was administrated 75 mg qd orally as a long-term antiplatelet prescription at least for months, and 2) hypoglycemia-inducible drugs were not used in the control arm. One investigator abstracted articles and performed a quality assessment. Uncertainties were resolved by discussions with two investigators independently. Odds ratio (OR) and risk difference (RD) were calculated and performed with subgroup analyses. The pre-specified protocol was registered in PROSPERO (CRD42022299622).

RESULTS

Six trials with 61,399 participants in total fulfilled the criteria and were included in the meta-analysis. Clopidogrel might not be associated with higher hypoglycemia odds (OR 0.95, 95% CI 0.65 to 1.40). However, Asian participants (p = 0.0437) seemed more likely to develop clopidogrel-associated hypoglycemia. Clopidogrel-associated hypoglycemia occurred at the highest rate of 0.03% (RD -0.00023, 95% CI -0.00077 to 0.00031), and this increased to 0.91% (RD 0.00210, 95% CI -0.00494 to 0.00914) in an aging population and to 0.18% (RD 0.00040, 95% CI -0.00096 to 0.00177) when Asian ratio of the population was elevated.

CONCLUSIONS

We raise the concern that clopidogrel might be a modifiable and causal risk factor of hypoglycemia. The Asian population might be more vulnerable and need additional care.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, identifier CRD42022299622.

Hirata's disease (insulin autoimmune syndrome) following envenomation by a common krait

Snakebite envenomation is known to cause local as well as systemic haematological, myotoxic and neurological effects. Adverse effects on the endocrine system following envenomation are rarely reported. Hirata's disease, also known as insulin autoimmune syndrome (IAS) is a rare disorder that causes hypoglycaemia due to excessive production of insulin autoantibodies. This report describes a rare case of IAS which developed in a snakebite victim following envenomation by a common krait and antivenom treatment. The patient was initially treated with dextrose and corticosteroids, although plasmapheresis was required to reduce the concentration of insulin antibodies and normalise the patient's glucose level. The patient then made an uneventful recovery without permanent sequelae. This report demonstrates the impacts of envenomation by a common krait on developing Hirata's disease and creates awareness among clinicians who treat snakebite envenomation.

Insulin Allergy to Detemir Followed by Rapid Onset of Diabetic Ketoacidosis: A Case Report and Literature Review

The management of diabetes mellitus in an insulin-dependent patient is challenging in the setting of concomitant antibody-mediated-insulin hypersensitivity. We report a case of a 62-year-old woman with pre-existing type 2 diabetes mellitus of 10 years duration who developed type 3 hypersensitivity reaction to insulin analogue detemir, and subsequently, severe diabetic ketoacidosis (DKA). She was C-peptide negative and was diagnosed with insulin-dependent diabetes. Despite increasing dose adjustments, insulin-meal matching, and compliance with insulin, she experienced episodes of unexpected hyperglycaemia and hypoglycaemia. The development of rash after detemir initiation and rapid progression to DKA suggests an aberrant immune response leading to the insulin allergy and antibody-induced interference with insulin analogues. Glycaemic control in the patient initially improved after being started on subcutaneous insulin infusion pump with reduced insulin requirements. However, after a year on pump therapy, localised insulin hypersensitivity reactions started, and glycaemic control gradually deteriorated.

Alpha lipoic acid with pulsed radiofrequency in treatment of chronic lumbosacral radicular pain: A prospective, randomized study

BACKGROUND

The effect of adding alpha lipoic acid (ALA) to pulsed radiofrequency (PRF) for treatment of lumbar-sacral pain was evaluated.

OBJECTIVE

to evaluate the effect of using ALA as an adjuvant therapy with PRF for treatment of chronic lumbosacral radicular pain caused by herniated disc.

METHODS

One hundred twenty patients with lumbo-sacral radicular pain allocated into 2 groups. Group I: treated with PRF at 42°C for 120 seconds. Group II: treated as in group I, plus oral ALA 600 mg (Thiotacid 600 mg, EVA PHARMA, Egypt) three times per day (1800 mg/day) for 3 weeks then 600 mg once daily for 2 weeks. The lumbo-sacral radicular pain evaluated using the numerical rating pain score and Oswestry Disability Index.

RESULTS

Success rate was significantly higher in group II at 3 and 6 months after intervention. The median values of the numerical rating pain score and the Oswestry Disability Index were significantly lower in group II with no significant difference in Epworth Sleepiness Scale. No major complications were reported in both groups.

CONCLUSION

The current study supports the use of ALA with PRF on the dorsal root ganglion for treating lumbosacral radicular pain.

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.

Analysis of the clinical characteristics of insulin autoimmune syndrome induced by alpha-lipoic acid

WHAT IS KNOWN AND OBJECTIVE

Alpha-lipoic acid (ALA) is widely used as a dietary supplement and antiageing agent. Insulin autoimmune syndrome (IAS) is the most serious adverse reaction reported with the use of ALA. The purpose of this study was to explore the clinical characteristics of ALA-induced IAS and provide a scientific reference for clinical diagnosis, treatment and prevention.

METHODS

We collected literature on IAS cases induced by ALA for retrospective analysis in Chinese and English.

RESULTS AND DISCUSSION

The median age of 37 patients (28 females and 9 males) was 61 years (range 32-82). The symptoms occurred at night and in the early morning (60.7%), in the late postprandial period (50.0%) or after fasting (35.7%), within hours in some patients and up to 2 months in others after stopping ALA or during medication treatment. Autonomic nervous system symptoms (81.1%) and neurological hypoglycaemia (64.9%) are the main clinical manifestations of hypoglycaemia. The blood glucose concentration at the onset of hypoglycaemia was 2.19 mmol/L (median, range 1.09-3.52), the insulin concentration was ≥100 μIU/ml (94.6%), and the C-peptide concentration was ≤20 ng/ml (83.3%). Testing for IgG insulin autoantibodies (IAAs) was positive in 37 patients. Pancreatic imaging was unremarkable on computed tomography (CT), magnetic resonance imaging (MRI) and abdominal sonography. Hypoglycaemia disappeared within 5 days to 8 months after withdrawing ALA alone or using corticosteroid treatment. IAA turned negative in 7 months (median; range 2-36). Follow-up showed no recurrent hypoglycaemic episodes at 7.25 months (median; range 1-36).

WHAT IS NEW AND CONCLUSION

ALA-induced IAS is a clinically rare autoimmune disease with hypoglycaemia that occurs during medication treatment or after drug withdrawal that should be treated promptly.

Long-term follow-up of insulin autoimmune syndrome in an elderly patient

An 84-year-old man was admitted to our hospital. His blood glucose level was 20 mg/dL. Since laboratory tests showed high titers of insulin antibodies, insulin autoimmune syndrome (IAS) was diagnosed. In　order to avoid hypoglycemia, steroids can be effective in the long-term management of IAS in elderly patients.

Insulin Autoimmune Syndrome - A Case Series

Insulin autoimmune syndrome, or Hirata's disease, is a rare cause of hypoglycaemia. It is characterised by spontaneous episodes of hypoglycaemia, without any exposure to exogenous insulin. The majority of cases are seen in the Japanese population and it is rarely found to affect other ethnicities. The recognition of this disease is important to avoid unnecessary investigations and procedures. Here, we report two cases of insulin autoimmune syndrome, which were diagnosed and managed in our institute.

Insulin autoimmune syndrome: A rare cause of hypoglycemia

Insulin autoimmune syndrome (IAS) is a rare cause of hyperinsulinemic hypoglycemia. It is due to autoantibodies to endogenous insulin in person who has never been sensitized to insulin by injections. IAS is a third leading cause of spontaneous hypoglycemia in Japan and it is increasingly being recognized worldwide in non-Asian population. However, we report a case of IAS in Asian male. A certain class of medication called sulfhydryl compounds have been shown to sometimes cause IAS. Recently a compound called alpha lipoic acid (ALA) has been associated with an increased risk of developing IAS. ALA is sometimes used for dieting purposes. We report a case of 36-year-old Indian male presented with symptoms of dizziness and feeling of hunger with sweating, noted to have low blood sugars on multiple occasions. There is a definite history of ALA compound intake as dietary supplements with multivitamins. Subsequently, he was diagnosed as a case of recurrent hypoglycemia from IAS due to ALA intake and managed accordingly.

Assessment of adverse reactions to α-lipoic acid containing dietary supplements through spontaneous reporting systems

BACKGROUND & AIMS

Alpha-lipoic acid (ALA)-containing dietary supplements are widely used in clinical practice, although their safety assessment is under-investigated. We characterize the safety profile of ALA-containing products by analysing spontaneous reports of suspected adverse reactions (ARs).

METHODS

Suspected ARs to ALA-containing products were extracted from the Italian Phytovigilance System (IPS), and scrutinized in terms of seriousness and causality (through WHO UMC system), with a specific focus on important (IMEs) and designated medical events (DMEs). To characterize the reporting profile from an international perspective, the WHO-VigiBase was also queried.

RESULTS

From March 2002 to February 2020, out of 2147 total reports, 116 reports concerning 212 ARs to ALA-containing products were collected. Women were involved in 68.1% of cases. Skin (44.9%) and gastrointestinal disorders (10.8%) were the most frequently represented ARs. Causality assessment resulted as definite (15), probable (35), possible (24), unlikely (5), and unclassifiable (37). In 70% of cases, events occurred within 30 days of ALA use. Forty-five reports were serious (38.8%), being insulin autoimmune syndrome the most frequently reported (N = 10). IMEs were recorded in 20 cases, including four DMEs (3 angioedema and one anaphylactic shock). Similar distribution emerged from the 5641 reports in the WHO-VigiBase.

CONCLUSIONS

The remarkable reporting of unpredictable skin, immune and hepatic ARs, coupled with seriousness, strong causality and early onset, calls for a) careful risk-benefit assessment of ALA-containing products by regulators; b) awareness and monitoring by clinicians and c) continuous vigilance of their safety profile through valuable spontaneous reporting systems such as IPS.

Nationwide survey of endogenous hyperinsulinemic hypoglycemia in Japan (2017-2018): Congenital hyperinsulinism, insulinoma, non-insulinoma pancreatogenous hypoglycemia syndrome and insulin autoimmune syndrome (Hirata's disease)

AIMS/INTRODUCTION

We aimed to investigate the nationwide incidence, treatment details and outcomes of patients with endogenous hyperinsulinemic hypoglycemia (EHH), including those with transient/persistent congenital hyperinsulinism (CHI), insulinoma, non-insulinoma pancreatogenous hypoglycemia syndrome and insulin autoimmune syndrome (Hirata's disease) in Japan.

MATERIALS AND METHODS

A nationwide, questionnaire-based survey was carried out to determine the number of patients with EHH who were treated for hypoglycemia or hypoglycemia-related complications in 2017-2018. The questionnaires were sent to all hospitals in Japan with >300 beds, and with pediatric and/or adult clinics likely managing EHH patients. The secondary questionnaires were sent to obtain the patients' date of birth, sex, age at onset, treatment details and post-treatment outcomes.

RESULTS

A total of 447 patients with CHI (197 transient CHI, 225 persistent CHI and 25, unknown histology), 205 with insulinoma (118 benign, 18 malignant and 69 unknown subtype), 111 with non-insulinoma pancreatogenous hypoglycemia syndrome (33 post-gastric surgery HH, 57 postprandial HH, 10 nesidioblastosis and 11 unknown subtype) and 22 with insulin autoimmune syndrome were identified. Novel findings included: (i) marked improvement in the prognosis of persistent CHI over the past 10 years; (ii) male dominance in the incidence of transient CHI; (iii) non-insulinoma pancreatogenous hypoglycemia syndrome emerging as the second most common form of EHH in adults; (iv) frequent association of diabetes mellitus with insulin autoimmune syndrome; and (v) frequent post-treatment residual hypoglycemia and impaired quality of life.

CONCLUSIONS

The first nationwide, all age group survey of EHH showed the current status of each type of EHH disorder and the unmet needs of the patients.

Insulin Autoimmune Syndrome: A Case of Clopidogrel-induced Autoimmune Hypoglycemia

CONTEXT

Insulin autoimmune syndrome (IAS) is characterized by hyperinsulinemic hypoglycemia with elevated anti-insulin antibodies. Most commonly observed in the Japanese population, elsewhere it is rare and associated with autoimmune diseases, plasma cell dyscrasias, or sulfhydryl group medications. The active metabolite of clopidogrel has a sulfhydryl group and here we report a case of clopidogrel-induced IAS.

CASE DESCRIPTION

A 67-year-old man was admitted with severe hyperinsulinemic hypoglycemia requiring continuous intravenous infusion of 10% dextrose to sustain euglycemia. His symptoms of hypoglycemia had started after commencing dual antiplatelet therapy (including clopidogrel) for ischemic heart disease 9 months earlier. The hypoglycemia was associated with elevated insulin, proinsulin, c-peptide, and anti-insulin antibody titers as well as the HLA-DRB1*04 haplotype. Multiple localizing studies were negative for an insulinoma. A diagnosis of IAS was thus made. Clopidogrel cessation, oral dexamethasone, and diazoxide therapy were not sufficient to safely wean the dextrose infusion. Plasma exchange was ultimately effective.

CONCLUSIONS

This case highlights a case of severe IAS. Given the ubiquity of clopidogrel, IAS should be remembered as a rare adverse effect.

HLA DRB1*0415: a new possible genetic susceptibility factor for Hirata's disease

CONTEXT

Hirata's disease (HD) is a rare autoimmune cause of hypoglycemia. Patients suffering from this condition have a genetic predisposition, determined by HLA DR4, with some differences in the worldwide population. In Caucasians HLA DRB1*0403 is the most frequent susceptibility background on which some drugs play as triggers.

CASE DESCRIPTION

We reported the case of a woman with several hypoglycemic episodes, characterized by high insulin and c-peptide levels. Biochemical and morphological exams excluded a neuroendocrine tumor. HD was diagnosed according to insulin autoantibodies positivity and patient's history, particularly about drugs taken. The HLA analysis revealed DRB1*0415 allele.

CONCLUSIONS

We found a potential new predisposing factor for HD, HLA DRB1*0415 allele, never described before as genetic background to insulin autoimmune syndrome in Caucasians.

Insulin Autoimmune Syndrome (Hirata Disease): A Comprehensive Review Fifty Years After Its First Description

Insulin autoimmune syndrome (IAS), also named Hirata's disease, is a rare condition characterized by hypoglycemic episodes due to the presence of high titers of insulin autoantibodies (IAA). IAS is a form of immune-mediated hypoglycemia, which develops when a triggering factor (ie, a medication or a viral infection) acts on an underlying predisposing genetic background. IAS pathogenesis involves the formation of insulin-IAA complexes that induce glycemic alterations with a double-phase mechanism: IAA prevent insulin to bind its receptor in the postprandial phase, possibly resulting in mild hyperglycemia; thereafter, insulin is released from the complexes irrespective of blood glucose concentrations, thus inducing hypoglycemia. The diagnosis of IAS is challenging, requiring a careful workup aimed at excluding other causes of hyperinsulinemic hypoglycemia. The gold standard for the definitive diagnosis is the finding of IAA in a blood sample. Because IAS is frequently a self-remitting disease, its management mostly consists of supportive measures, such as dietary modifications, aimed at preventing the development of hypoglycemia. Pharmacological therapies may occasionally be necessary for patients presenting with severe manifestations of IAS. Available therapies may include drugs that reduce pancreatic insulin secretion (somatostatin analogues and diazoxide, for instance) and immunosuppressive agents (glucocorticoids, azathioprine and rituximab). The purpose of this review is to provide a comprehensive analysis of the disease, by describing the burden of knowledge that has been obtained in the 50 years following its first description, took in 1970, and by highlighting the points that are still unclear in its pathogenesis and management.

Insulin Autoimmune Syndrome After Exposure to Clopidogrel: A Case Report

BACKGROUND

Insulin autoimmune syndrome (IAS) is a rare cause of hypoglycemia that is characterized by hyperinsulinemia, hypoglycemia, and a high autoantibody titer. About 50% of patients with IAS have taken a medication containing sulfhydryl (-SH) groups. We present a case of IAS that developed after taking clopidogrel, a drug with an active metabolite that contains an SH-group.

CASE REPORT

IAS was suspected in a 63-year-old Chinese man because of high concentrations of insulin and C-peptide during hypoglycemic episodes, and positivity for anti-insulin autoantibody (IAA). During his first episode of hypoglycemia, no trigger medication was identified and prednisone therapy was effective. However, imaging examination revealed a colonic carcinoma and the patient was discharged to undergo surgery. He had no episodes of hypoglycemia for 10 weeks after discontinuation of the prednisone, but then hypoglycemia recurred. A review of his medication revealed that he had taken a 10-day course of clopidogrel just before the recurrence. Therefore, a specialized multidisciplinary team consisting of endocrinologists, dieticians, and clinical pharmacists took charge of his management. Prednisone therapy was restarted and tapered off over 16 weeks. The patient also consumed small, frequent, low-carbohydrate meals and was instructed to avoid trigger medications. No further episodes of hypoglycemia were detected. His insulin and C-peptide concentrations and his anti-IAA index normalized during the follow-up period.

CONCLUSION

SH-group-containing drugs might induce or exacerbate hypoglycemia in patients with a history of IAS. Furthermore, patients with IAS can benefit from multidisciplinary team management. We suggest herein an evaluation process for patients suspected of IAS.

Insulin Autoimmune Syndrome Diagnosis and Therapy in a Single Chinese Center

PURPOSE

Insulin autoimmune syndrome (IAS) is a relatively rare cause of hypoglycemia characterized by endogenous hyperinsulinism and autoantibodies against endogenous insulin despite no prior exposure to exogenous insulin. We present a series of IAS cases and describe the clinical characteristics of these cases.

METHODS

The medical records of inpatients with the final diagnosis of IAS were collected from August 2007 to August 2017 in Peking Union Medical College Hospital. Clinical characteristics and laboratory test results were summarized. The results of serum glucose, insulin, true insulin, and C-peptide testing during 5-h oral glucose tolerance tests were also summarized. Circulating immune complexes were assessed qualitatively by precipitation with polyethylene glycol (PEG) in some patients.

FINDINGS

Sixteen patients were included in this study. Insulin autoimmune antibody test results were found positive in 12 patients and weakly positive in 1 patient. Nine patients had an insulin to C-peptide molar ratio >1, whereas 6 patients had an insulin to C-peptide molar ratio <1. Circulating immune complexes were verified in all 4 patients who had been assessed with PEG. During 5-h oral glucose tolerance tests, the C-peptide level responded earlier to the glucose tolerance and had a shorter peak value period compared with insulin, although C-peptide's fluctuation still lagged behind the glucose fluctuation. Three patients presented with self-limited disease courses or limited disease course after discontinuing use of the sulfhydryl group drugs. Some patients' symptoms were relieved after small frequent meals, and some were relieved after taking acarbose. Only 3 patients took glucocorticoids as the anti-immune therapy.

IMPLICATIONS

The insulin to C-peptide molar ratios were not consistently >1 in patients with confirmed diagnoses of IAS in our study, which suggested the low sensitivity of insulin to C-peptide molar ratio to detect IAS. The therapy in our study also revealed the self-limited disease course of IAS, and despite the effectiveness of anti-immunity therapy, convenient therapy, such as frequent small meals and adding acarbose, performed well in many patients.

Insulin autoimmune syndrome as a cause of recurrent hypoglycemia in a carbimazole user: a case report from Nepal

Insulin autoimmune syndrome (IAS) is a rare cause of nondiabetic hypoglycemia characterized by hyperinsulinemia and autoantibodies to endogenous insulin without prior exposure to exogenous insulin. We report a drug-induced case of IAS in a 59-year-old Nepalese female. She had been taking carbimazole for Graves’ disease and later presented with recurrent episodes of hypoglycemia, with laboratory findings of low blood glucose, increased molar ratio of insulin to C-peptide, and elevated autoantibodies to insulin. IAS should be considered while evaluating hypoglycemia to prevent unwarranted invasive procedures and surgical interventions.

Enhancement of postprandial endogenous insulin secretion rather than exogenous insulin injection ameliorated insulin antibody-induced unstable diabetes: a case report

BACKGROUND

Insulin injection, especially with insulin analogs, occasionally induces the production of insulin antibodies with high binding capacity and low affinity, similar to the insulin autoantibodies characteristic of insulin autoimmune syndrome (IAS). Production of these "IAS-like" insulin antibodies causes marked glycemic fluctuations with postprandial hyperglycemia and fasting hypoglycemia.

CASE PRESENTATION

A 66-year-old man with a 27-year history of diabetes was admitted because of marked glycemic fluctuations. Human insulin treatment had been initiated at age 56, followed by multiple daily injections of insulin analogs 5 years later. After the initial year of insulin analog treatment, the patient began to experience frequent morning hypoglycemic attacks and day-time hyperglycemia. Marked hyperinsulinemia (4500 μU/mL) and high titers of insulin antibodies (80.4%) with high binding capacity and low affinity indicated that IAS-like insulin antibodies were causing severe glucose fluctuations. Altering insulin formulations (insulin aspart → regular human insulin→ insulin lispro) proved to be ineffective. After several therapeutic trials, cessation of exogenous insulin and addition of mitiglinide to liraglutide with voglibose finally attenuated glycemic fluctuations with increased postprandial insulin secretion. Continuous glucose monitoring revealed improvement of morning hypoglycemia and postprandial hyperglycemia with smaller mean amplitude of glycemic excursion. Therefore, compared to exogenously injected insulin, endogenously secreted insulin directly and rapidly acts on hepatocytes and suppresses postprandial glucose output.

CONCLUSIONS

Proper enhancement of postprandial endogenous insulin aimed at suppressing postprandial glucose output without stimulating excessive glucose uptake in the periphery is potentially useful for treating diabetes with insulin antibody-induced glycemic instability.

Insulin autoimmune syndrome possibly caused by coenzyme Q10

A 52-year-old woman was transported for reduced consciousness. Her blood glucose was only 19 mg/dL, but her blood immunoreactive insulin and insulin antibody levels were high at 250 μU/mL and 50 U/mL, respectively. She had no history of insulin treatment, but she had been taking coenzyme Q10 supplements for three months. Her human leukocyte antigen serotype was DR4. After stopping coenzyme Q10, her hypoglycemia disappeared and immunoreactive insulin and insulin antibody levels normalized. Based on the above, she was diagnosed with insulin autoimmune syndrome caused by coenzyme Q10. It is necessary to be aware of the onset of insulin autoimmune syndrome due to coenzyme Q10. Its pathogenesis requires clarification.

Insulin autoimmune syndrome in an Argentine woman taking α-lipoic acid: A case report and review of the literature

Insulin autoimmune syndrome is an unusual cause of spontaneous hypoglycaemia in non-Asian populations. In the majority of cases, this syndrome appears a few weeks after the administration of drugs containing a sulfhydryl group. A strong association between this syndrome and HLA-DR4 has been shown. Only seven cases have been described in non-Asian patients. We report the first case of insulin autoimmune syndrome in an Argentine woman taking alfa-lipoic acid. She developed hypoglycaemic symptoms approximately 1 month after starting therapy. Blood sampling collected during an episode of symptomatic hypoglycaemia showed low blood glucose level (2.39 mmol/L), high level of serum insulin (1971.55 pmol/L), inappropriately high level of C-peptide (2.36 nmol/L) and high levels of insulin antibodies (274.78 IU/mL). HLA-DNA typing identified DRB1*04:03. Due to the widespread use of alfa-lipoic acid for its antioxidant properties, clinicians should be aware that it may trigger an autoimmune hypoglycaemia in people with a genetic predisposition.

Autoimmune hypoglycaemia caused by alpha-lipoic acid: a rare condition in Caucasian patients

Insulin autoimmune syndrome (IAS), a rare cause of autoimmune hyperinsulinaemic hypoglycaemia, is relatively well known in Japan. The incidence in Caucasians is less than one-fifth of that reported in Japanese people, but it is becoming increasingly recognised worldwide in non-Asians as well. Drugs containing sulphydryl groups are known to be associated with the disease in genetically predisposed individuals. Moreover, several recent reports showed a direct association between the onset of IAS and the consumption of dietary supplements containing alpha-lipoic acid (LA). Insulinoma remains the most prevalent cause of hypersulinaemic hypoglycaemia in Caucasians. Consequently, primary investigation in these patients is generally focused on localisation of the pancreatic tumour, often with invasive procedures followed by surgery. We described a case of an Italian woman presenting to us with severe recurrent hypoglycaemia associated with high insulin and C-peptide levels and no evidence of pancreatic lesions at imaging diagnostic procedures. She had taken LA until 2 weeks before hospitalisation. After an evaluation of her drug history, an autoimmune form of hypoglycaemia was suspected and the titre of insulin autoantibodies was found to be markedly elevated. This allowed us to diagnose LA-related IAS, thus preventing any unnecessary surgery and avoiding invasive diagnostic interventions. Learning points: IAS is a rare cause of hyperinsulinaemic hypoglycaemia that typically affects Asian population, but it has been increasingly recognised in Caucasian patients. It should be considered among the differential diagnosis of hyperinsulinaemic hypoglycaemia to avoid unnecessary diagnostic investigations and surgery. It should be suspected in the presence of very high serum insulin levels (100-10 000 μU/mL) associated with high C-peptide levels. There is a strong association with administration of drugs containing sulphydryl groups included LA, a dietary supplement commonly used in Western countries to treat peripheral neuropathy.

Spontaneously remitting insulin autoimmune syndrome in a patient taking alpha-lipoic acid

Insulin autoimmune syndrome (IAS), or Hirata disease, is a rare hypoglycaemic disorder caused by the presence of high titer of insulin autoantibodies (IAA) in patients without previous exposure to exogenous insulin. Even though its pathogenesis is not fully understood, striking evidences link IAS to previous exposure to sulphydryl-containing medications, like alpha-lipoic acid, a widely used nutritional supplement. Although challenging, a careful differential diagnosis from other causes of hyperinsulinaemic hypoglycaemia (such as insulinoma) is mandatory, since these conditions require different therapeutic approaches. In the present study, we report a 35-year-old woman originally from Sri Lanka who was referred to our University Hospital on suspicion of occult insulinoma. Her medical history was positive for endometriosis, treated with estroprogestins and alpha-lipoic acid. The latter supplement was begun 2 weeks before the first hypoglycaemic episode. Our tests confirmed the presence of hypoglycaemia associated with high insulin and C-peptide concentrations. When insulin concentrations were compared using different assays, the results were significantly different. Moreover, insulin values significantly decreased after precipitation with polyethylene glycol. An assay for IAA proved positive (530 U/mL). A genetic analysis revealed the presence of HLA-DRB1*04,15, an immunogenetic determinant associated with IAS. On the basis of clinical data we avoided a first-line approach with immunosuppressive treatments, and the patient was advised to modify her diet, with the introduction of frequent low-caloric meals. During follow-up evaluations, glucose levels (registered trough a flash glucose monitoring system) resulted progressively more stable. IAA titer progressively decreased, being undetectable by the fifteenth month, thus indicating the remission of the IAS. Learning points: Insulin autoimmune syndrome (IAS) is a rare cause of hyperinsulinaemic hypoglycaemia, whose prevalence is higher in East Asian populations due to the higher prevalence of specific immunogenetic determinants. Nevertheless, an increasing number of IAS cases is being reported worldwide, due to the wide diffusion of medications such as alpha-lipoic acid. Differential diagnosis of IAS from other causes of hyperinsulinemic hypoglycaemia is challenging. Even though many tests can be suggestive of IAS, the gold standard remains the detection of IAAs, despite that dedicated commercial kits are not widely available. The therapeutic approach to IAS is problematic. As a matter of fact IAS is often a self-remitting disease, but sometimes needs aggressive immunosuppression. The benefits and risks of any therapeutic choice should be carefully weighted and tailored on the single patient.

Insulin autoimmune syndrome in an occidental woman: a case report and literature review

Insulin autoimmune syndrome (IAS, Hirata's disease) is a rare hypoglycemic disorder characterized by spontaneous hypoglycemia associated with extremely high circulating insulin levels and positive anti-insulin antibody results. Thus far, most cases have been reported in Asian countries, notably Japan, with few cases reported in western countries. As a possible cause, it is associated with the use of drugs containing sulfhydryl radicals, such as captopril. This report refers to a 63-year-old female Brazilian patient with a history of postprandial hypoglycemia. After extensive investigation and exclusion of other causes, her hyperinsulinemic hypoglycemia was considered to have likely been induced by captopril. Most cases of IAS are self-limiting. However, dietary management, corticosteroids, plasmapheresis, and rituximab have already been used to treat patients with IAS. In our case, after discontinuation of captopril, an initial decrease in insulin autoantibody levels was observed followed by improvement in episodes of hypoglycemia. Although it is a rare disease, IAS should be considered in the differential diagnosis of endogenous hyperinsulinemic hypoglycemia. Patients with suspected IAS must be screened for autoimmunity-related drugs for insulin. Initial clinical suspicion of IAS can avoid unnecessary costs associated with imaging examinations and/or invasive surgical procedures.

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.

Potential cause-effect relationship between insulin autoimmune syndrome and alpha lipoic acid: Two case reports

OBJECTIVES

Insulin autoimmune syndrome (IAS) or Hirata disease is a rare cause of autoimmune hypoglycemia with apparent high insulin levels and anti-insulin autoantibodies and was first described by Hirata in Japan in 1970. IAS cases are usually related to exposure to sulfhydryl-containing drugs, which stimulate the production of insulin autoantibodies. Among sulfhydryl-containing compounds, alpha lipoic acid (ALA) has recently emerged as a cause of IAS. After the first observations of ALA-induced IAS were reported in Japan in 2006, an increasing number of cases related to ALA administration have been described. An Italian group recently reported on six cases of IAS of which one was associated with HLA-DRB1*04:06 and the remaining five with HLA-DRB1*04:03. This suggests that the latter is potentially involved in the genetic susceptibility of people of European descent to IAS.

METHODS

Here, we describe two new cases of IAS in women that were triggered by ALA.

RESULTS

Both cases are associated with HLA-DRB1*04:03 and confirm the evidence that HLA-DRB1*04:03 rather than HLA-DRB1*04:06 is specifically related to IAS susceptibility in Europeans.

CONCLUSIONS

Case reports of ALA-induced hypoglycemic episodes highlight the need for greater care in prescribing ALA supplementation as well as the identification of specific and personalized therapeutic targets.

Insulin autoimmune syndrome in a pregnant female: A rare case report

RATIONALE

Insulin autoimmune syndrome (IAS) is an uncommon disorder characterized by hyperinsulinemic hypoglycemia related to insulin-binding autoantibodies. To the best of our knowledge, we report the first case of a pregnant female with IAS.

PATIENT CONCERNS

The 26-year-old patient with Graves disease and 10 weeks pregnant developed IAS after approximately 6 months treatment with methimazole. The patient exhibited recurrent spontaneous hypoglycemia.

DIAGNOSES

On evaluation, laboratory findings detected both high fasting insulin (>1000 mIU/L) and insulin autoantibodies. An oral glucose tolerance test showed elevated insulin concentrations with disproportionately elevated C-peptide levels. The imaging study showed nomasslesionsinthepancreas,and the patient was clinically diagnosed with IAS.

INTERVENTIONS

The patient had an abortion, discontinued methimazole and switched to oral prednisone (30 mg once daily) and propylth- iouracil (100 mg 3 times daily) for 3 months.

OUTCOMES

At the 3-month follow-up visit, hypoglycemic episodes had disappeared and insulin antibody levels were no longer detectable.

LESSONS

We have described this case and reviewed the relevant literature concerning diagnosis and treatment of IAS. Importantly, this case indicates that clinicians should view pregnancy as another factor of hypoglycemia in IAS.

Insulin autoimmune syndrome (Hirata’s disease) in an Italian patient: a case report and review of the literature

We describe the case of a 54-year-old Caucasian Italian male experiencing episodes of hypoglycemia, occurring mainly after meals. He had never been exposed to insulin and was taking ramipril, flecainide and acetylsalicylic acid. An oral glucose tolerance test (OGTT) showed high blood glucose levels diagnostic for diabetes mellitus at 120 min and hypoglycemia with inappropriately high insulin levels at 240 min. The 72-h fasting test, abdominal computed tomography (CT) and positron emission tomography-CT were normal. Insulin autoantibodies were positive at high titers, prompting a diagnosis of insulin autoimmune syndrome (IAS). The patient was advised to take frequent, small meals and thus achieved a good control of his hypoglycemic symptoms. After 18 months of this dietary management, his insulin autoantibody levels decreased considerably but remained detectable. During an OGTT, his blood glucose levels at 120 min were now indicative of an impaired glucose tolerance rather than diabetes, and there was improvement in the glucose nadir. The patient had no other clinical or latent autoimmune diseases. Here we discuss the main features of IAS (also known as Hirata’s disease) and review the cases of IAS reported in Italy to date.

"Riding High on Low Fuel" - Our Experience with Endogenous Hyperinsulinemic Hypoglycemia

INTRODUCTION

Endogenous hyperinsulinemic hypoglycemia (EHH) is a condition in which the insulin levels are inappropriately high in the presence of low plasma glucose.

MATERIALS AND METHODS

We did a retrospective analysis of case records of those patients admitted and evaluated for EHH from June 2004 to June 2016 in our center, excluding those that were diagnosed with reactive hypoglycemia. We collected data regarding demographics, clinical presentation, laboratory results, localization techniques, and treatment administered.

RESULTS

Sixteen patients who were admitted for evaluation based on history suggestive of repeated hypoglycemic episodes were included in the study. All but one pregnant patient was subjected to a supervised fast in the hospital. All patients developed hypoglycemia (defined using Whipple's triad) within the first 24 h. Three patients had autoimmune hypoglycemia which differed significantly from insulinoma-mediated hypoglycemia in certain clinical and laboratory parameters. They were older in age with marked fluctuations in the 24 h glucose profile ranging from frank hypoglycemia to frank hyperglycemia. The insulin levels were markedly elevated in this group of patients along with a significantly elevated insulin C peptide molar ratio (ICMR) when compared with patients with insulinoma-mediated hypoglycemia.

CONCLUSIONS

Although insulinoma is the most common cause of EHH, autoimmune hypoglycemia should be considered as a differential diagnosis, particularly in older individuals with plasma glucose values increasing to the hyperglycemic range. Degree of elevation of insulin levels and ICMR may provide additional clues. Overall, the survival and prognosis of patients with EHH are excellent.

MANAGEMENT OF ENDOCRINE DISEASE: Pathogenesis and management of hypoglycemia

Glucose is the main substrate utilized by the brain and as such multiple regulatory mechanisms exist to maintain glucose concentrations. When these mechanisms fail or are defective, hypoglycemia ensues. Due to these robust mechanisms, hypoglycemia is uncommon and usually occurs in the setting of the treatment of diabetes using glucose-lowering agents such as sulfonylureas or insulin. The symptoms of hypoglycemia are non-specific and as such it is important to confirm hypoglycemia by establishing the presence of Whipple's triad before embarking on an evaluation for hypoglycemia. When possible, evaluation of hypoglycemia should be carried out at the time of spontaneous occurrence of symptoms. If this is not possible then one would want to create the circumstances under which symptoms occur. In cases where symptoms occur in the post absorptive state, a 72-h fast should be performed. Likewise, if symptoms occur after a meal then a mixed meal study may be the test of choice. The causes of endogenous hyperinsulinemic hypoglycemia include insulinoma, post-bariatric hypoglycemia and noninsulinoma pancreatogenous hypoglycemia syndrome. Autoimmune hypoglycemia syndrome is clinically and biochemically similar to insulinoma but associated with high levels of insulin antibodies and plasma insulin. Other important causes of hypoglycemia include medications, non-islet cell tumors, hormonal deficiencies, critical illness and factitious hypoglycemia. We provide an overview of the pathogenesis and management of hypoglycemia in these situations.

The insulin autoimmune syndrome (IAS) as a cause of hypoglycaemia: an update on the pathophysiology, biochemical investigations and diagnosis

Insulin autoimmune syndrome (IAS) is considered to be very rare in Caucasians. Understanding its pathophysiology is paramount in (a) appreciating its potential impact on analyses of pancreatic hormones and (b) explaining its highly variable clinical manifestations in non-diabetic, non-acutely ill patients with indeterminate hypoglycaemia. The underlying aetiology of IAS is the presence of variable affinity/avidity endogenous insulin antibodies in significant amounts. The two types of insulin antibodies namely antibodies which bind insulin and/or proinsulin(s) and receptor antibodies (insulin mimetic) will be discussed. Their biochemical and immunological roles in causing hypoglycaemia will be highlighted. Clinical manifestations of IAS can vary from mild and transient to spontaneous, severe and protracted hypoglycaemia necessitating in extreme cases plasmapheresis for glycaemic control. Antibodies of IAS can interfere in pancreatic immunoassay tests causing erroneous and potentially misleading results. Thorough testing for endogenous insulin antibodies must be considered in the investigations of non-diabetic, non-acutely ill patients with indeterminate and/or unexplained hypoglycaemia.

Methimazole-induced insulin autoimmune syndrome

BACKGROUND

Hypoglycemia in a critical care setting is often multifactorial with iatrogenic insulin use, sulfonylurea (SU) use, sepsis, adrenal insufficiency and insulinoma among the common causes. Insulin autoimmune syndrome (IAS) is a rare cause of hypoglycemia characterized by the presence of insulin-binding autoantibodies to the sulfhydryl group-containing agents. We report a case of methimazole-induced IAS managed in the intensive care unit.

CASE PRESENTATION

A 76-year-old woman with a history of primary hyperthyroidism was sent from a nursing home for unresponsiveness. Vital signs were significant for hypotension (74/46) and low blood sugars. Fluid resuscitations with normal saline and 50% dextrose stabilized the blood pressure (BP) to 135/75 and her blood glucose to 264. Due to respiratory distress and septic appearance, she required emergency intubation. Nursing home medications were noted for methimazole and absence of any insulin or SU use. Empiric antibiotic treatment was started and fluid resuscitation was continued while home medications were held. Her laboratory values were significant for elevated creatinine, lactic acid, serum cortisol, C-peptide, and insulin. Her cultures, SU screen and computerized tomography (CT) scan were negative for significant findings. On day 2, in addition to 10% dextrose, octreotide was initiated for recurrent hypoglycemia. Her blood glucose (BG) continued to drop throughout the day for which she required glucagon support and a D20 infusion. By day 4, the rate of infusion was titrated up and her BG continued to drop to <60 mg/dl despite D20, octreotide and tube feeds with concentrated calories (1.5 cal/ml). Due to her declining health, her family endorsed palliative care and she was extubated. After day 11, her hypoglycemic episodes resolved and she remained endogenously euglycemic.

CONCLUSIONS

IAS is associated with methimazole use due to formation of autoantibodies to insulin after its interaction with Sulfhydryl (SH) group in methimazole. While IAS is a rare entity, it demands consideration in hypoglycemia in patients with autoimmune conditions.

Spontaneous hypoglycaemia in a patient with Graves' disease

A 23-year-old man, on treatment for Graves' disease, presented to the emergency department, with 2 separate episodes of loss of consciousness. During the first episode, the initial serum glucose was 19 mg/mL, and 44 mg/dL during the second episode. The patient was non-diabetic, and had elevated blood insulin, C peptide and insulin antibody levels. His abdominal radiographic findings were normal. He was diagnosed with Hirata disease, and put on propylthiouracil as a replacement for carbimazole. Hypoglycaemia was managed with dextrose infusions and frequent meals. The patient's condition improved and he had no further episodes of hypoglycaemia during the follow-up period.

Two Sisters with Graves' Disease and Similar Clinical Features who Tested Positive for Anti-insulin Antibodies after Thiamazole Treatment

The older of a pair of sisters experienced hypoglycemia after the start of thiamazole (MMI) treatment. Based on a high insulin antibody level, she was diagnosed with insulin autoimmune syndrome (IAS). HLA-DNA typing identified DRB1*04:06. Although a 75-g oral glucose tolerance test (OGTT) showed biphasic insulin secretion, the secretion pattern became monophasic after discontinuation of the MMI. The younger sister was diagnosed with IAS after the start of MMI treatment. HLA-DNA typing identified DRB1*04:06. The 75-g OGTT showed biphasic insulin secretion, but it became monophasic after discontinuation of the MMI. According to the similar insulin secretion kinetics in the two sisters with IAS, we suspect that a genetic predisposition may be associated with the features of anti-insulin antibodies.

Rare association of insulin autoimmune syndrome with ankylosing spondylitis

Insulin autoimmune syndrome (IAS) is a rare cause of hyperinsulinemic hypoglycaemia, which is known to occur in association with the use of sulfhydryl-containing drugs and autoimmune disorders. We describe a patient with hitherto an unreported association of IAS with ankylosing spondylitis. We have also performed and described a simplified method of polyethylene glycol (PEG) precipitation of an insulin bound antibody in the serum.

Immunological hypoglycemia associated with insulin antibodies induced by exogenous insulin in 11 Chinese patients with diabetes

AIMS

To investigate the characteristics of immunological hypoglycemia associated with insulin antibodies (IAbs) induced by exogenous insulin in Chinese patients with diabetes.

METHODS

The clinical data of patients with immunological hypoglycemia due to IAbs were retrospectively analyzed by screening patients with diabetes discharged from West China Hospital from 2007 to 2013.

RESULTS

A total of 11 patients (eight men and three women) were identified. Insulin-C-peptide separation was found in all patients via insulin and C-peptide release test. Previous insulin use was ceased after admission and was switched to oral hypoglycemic agents (OHAs) (8/11), lifestyle modification only (2/11), or regular human insulin (1/11). Hypoglycemia was ameliorated after a median of 20 days (interquartile range [IQR], 11-40), while IAbs turned negative after a median of 17 months (IQR, 4-19), and serum immunoreactive insulin (IRI) levels dropped substantially after a median of 22 months (IQR, 9-32) in these cases.

CONCLUSIONS

In insulin-treated patients with unexpected and refractory hypoglycemia even after insulin therapy was gradually reduced or even withdrawn, IAbs induced by exogenous insulin should be considered, and insulin withdrawal might be promptly needed. The course of immunological hypoglycemia was benign and self-limited.