Type B insulin resistance syndrome: a systematic review

Insulin autoimmune syndrome in a patient with vitiligo: a case report and review of literature

BACKGROUND

Hirata syndrome is a rare cause of hypoglycemia characterized by high insulin levels and the presence of insulin autoantibodies. This case report aims to introduce Hirata syndrome as a cause of fasting hypoglycemia in a patient with autoimmune diseases, such as vitiligo. Notably, this is the first reported case of insulin autoimmune syndrome in Iran.

CASE PRESENTATION

A 47-year-old Iranian female with no prior history of diabetes but a 10-year history of vitiligo experienced recurrent hypoglycemia symptoms as evidenced by neuroglycopenia and neurological symptoms. Biochemical evaluation revealed fasting hypoglycemia (35 mg/dL), hyperinsulinemia (> 2000 µIU/mL), elevated C-peptide (23 ng/mL), and negative sulfonylurea screening. Imaging studies excluded other causes, such as insulinoma. Considering the high level of insulin autoantibodies, the final diagnosis was insulin autoimmune syndrome. A small, frequent, low carbohydrate diet was considered as the treatment plan to relieve the hypoglycemic symptoms. The patient provided written consent authorizing the utilization of her medical data and the publication of this case study.

CONCLUSION

In patients without diabetes with autoimmune diseases, such as vitiligo, who present with hyperinsulinemic hypoglycemia accompanied by elevated C-peptide levels, insulin autoimmune syndrome can be considered as a diagnosis.

Newly emerging type B insulin resistance (TBIR) during treatment with eculizumab for AQP4-IgG-positive neuromyelitis optica spectrum disorder (NMOSD): fatal outcome

BACKGROUND

Aquaporin-4 immunoglobulin G (AQP4-IgG) antibody-positive neuromyelitis optica spectrum disorders (NMOSD) are frequently associated with other autoimmune disorders, including systemic lupus erythematosus (SLE). Eculizumab (ECU) is a highly effective long-term treatment for NMOSD. However, ECU is known to increase significantly the risk of infection with encapsulated bacteria and sepsis. Recently, increased insulin resistance (IR) in patients with NMOSD has been suggested. Type B IR (TBIR) is a rare autoimmune condition often accompanying or preceding SLE. TBIR has not yet been reported in NMOSD.

OBJECTIVE

To report an ECU-treated patient with AQP4-IgG-positive NMOSD who developed fatal septic complications after the emergence of TBIR.

METHODS

Description of the clinical course over a period of 8 years.

RESULTS

A female patient was diagnosed with NMOSD at the age of 16 years. A variety of disease-modifying drugs failed to achieve sufficient disease control, resulting in severe tetraparesis. Treatment with ECU was started 6 years after NMOSD diagnosis and stabilized the disease. The patient developed TBIR 8 months after initiation of ECU therapy. Following high-dose intravenous methylprednisolone therapy for a clinical relapse and three further courses of ECU, the patient was admitted with severe pneumonia caused by the encapsulated bacterium Klebsiella pneumoniae and hypoglycemia. Despite multimodal therapy, the patient died from sepsis-related multiorgan failure 18 months after initiation of ECU.

CONCLUSIONS

TBIR should be considered as differential diagnosis in patients with NMOSD presenting with disturbed glucose metabolism, irrespective of the presence of SLE. More real-world data are needed on the risk/benefit ratio of ECU treatment in patients who have co-existing autoimmune comorbidities that may compromise immune function. Strategies to mitigate the risk of serious infection in patients treated with ECU are discussed.

A rare case of autoimmune dysglycemia syndrome associated with systemic lupus erythematosus and dermatomyositis

Autoimmune dysglycemia syndrome (ADS) is a rare condition that presents as episodes of hypoglycemia as well as hyperglycemia and is classified as insulin autoimmune syndrome (IAS) and type B insulin resistance (TBIR). Autoimmunity plays a key role in the pathogenesis of this disorder, as evidenced by the presence of autoantibodies against endogenous insulin or the insulin receptor, and by its association with rheumatologic disorders. Treatment usually includes glycemic control and immunomodulatory agents. We report a case of a 31-year-old woman who was admitted for severe hypoglycemia. Further workup revealed underlying systemic lupus erythematosus (SLE) with renal involvement. During hospitalization, she continued to experience episodes of fasting hypoglycemia, as well as episodes of postprandial hyperglycemia. Hypoglycemia associated with a high serum insulin concentration and positive anti-insulin antibodies were consistent with IAS. Likewise, hyperglycemia and hypoglycemia in association with weight loss, acanthosis nigricans, polycystic ovarian syndrome, and normotriglyceridemia strongly suggested TBIR, although testing for antibodies against the insulin receptor was not available in Peru. Immunosuppressive therapy and metformin were indicated, resulting in remission of SLE and ADS. Years later, the patient exhibited features of dermatomyositis, such as Raynaud’s phenomenon, muscular weakness, heliotrope exanthema, and elevated muscle enzymes. Once again, the patient received immunosuppressive therapy. ADS is an infrequent cause of hypoglycemia, and the coexistence of its two pathophysiological mechanisms in a patient with SLE and subsequent development of dermatomyositis is even more rare. Our case is the first one reported describing this association.

A rare case of autoimmune dysglycemia syndrome associated with systemic lupus erythematosus and dermatomyositis

Autoimmune dysglycemia syndrome (ADS) is a rare condition that presents as episodes of hypoglycemia as well as hyperglycemia and is classified as insulin autoimmune syndrome (IAS) and type B insulin resistance (TBIR). Autoimmunity plays a key role in the pathogenesis of this disorder, as evidenced by the presence of autoantibodies against endogenous insulin or the insulin receptor, and by its association with rheumatologic disorders. Treatment usually includes glycemic control and immunomodulatory agents. We report a case of a 31-year-old woman who was admitted for severe hypoglycemia. Further workup revealed underlying systemic lupus erythematosus (SLE) with renal involvement. During hospitalization, she continued to experience episodes of fasting hypoglycemia, as well as episodes of postprandial hyperglycemia. Hypoglycemia associated with a high serum insulin concentration and positive anti-insulin antibodies were consistent with IAS. Likewise, hyperglycemia and hypoglycemia in association with weight loss, acanthosis nigricans, polycystic ovarian syndrome, and normotriglyceridemia strongly suggested TBIR, although testing for antibodies against the insulin receptor was not available in Peru. Immunosuppressive therapy and metformin were indicated, resulting in remission of SLE and ADS. Years later, the patient exhibited features of dermatomyositis, such as Raynaud’s phenomenon, muscular weakness, heliotrope exanthema, and elevated muscle enzymes. Once again, the patient received immunosuppressive therapy. ADS is an infrequent cause of hypoglycemia, and the coexistence of its two pathophysiological mechanisms in a patient with SLE and subsequent development of dermatomyositis is even more rare. Our case is the first one reported describing this association.

Endogenous hyperinsulinemic hypoglycemia: case series and literature review

PURPOSE

Endogenous hyperinsulinemic hypoglycemia (EHH) is an uncommon disease characterized by inappropriately high plasma insulin levels despite low plasma glucose levels. Some rare etiologies can lead to EHH. Correct diagnosis is a prerequisite for treatment. Hence, although challenging, it is crucial for patients with EHH to identify the different causes.

METHODS

We describe a case series of three patients, all of whom had obvious hypoglycemic symptoms and extraordinary hyperinsulinemia. Their plasma glucose, insulin, and C-peptide levels were tested simultaneously when hypoglycemia occurred. Moreover, other biochemical indices and relevant antibody levels were measured and imaging examinations were conducted.

RESULTS

According to their medical history, physical examination, laboratory results, and imaging findings, the three patients were diagnosed with insulinoma, type B insulin resistance syndrome, and insulin autoimmune syndrome. After precise treatments, hypoglycemia was ultimately eliminated.

CONCLUSION

Although these diseases have similar symptoms and biochemical abnormalities, the treatment and prognosis are different. The case series presented here highlights the challenges in the differential diagnosis of EHH. An accurate diagnosis is necessary for hypoglycemia treatment.

Late Systemic Lupus Erythematosus-Associated Insulin Resistance Syndrome: A Rare Cause of De Novo Diabetes Mellitus

The association of type B insulin resistance syndrome (TBIRS) due to autoimmune diseases such as systemic lupus erythematosus (SLE) is uncommon. This is partly due to the lack of established criteria for the diagnosis of this resistance. However, some clinical aspects may suggest that the diagnosis does not necessarily have to be positive insulin receptor antibodies as such patients could respond to immunosuppressive treatment. Methods. We describe a case and have performed a literature review on PubMed/MEDLINE, EMBASE, and Google Scholar bibliographic databases to identify all case reports. All available studies from January 1975 through December 2020 were included. Data collected were tabulated, and outcomes were analyzed cumulatively. Results. Thirty-one cases of TBIRS associated with SLE have been described. These patients presented with catabolic symptoms and hyperglycemia in most cases, with an average time from the onset of symptoms of four months. In addition to that clinical characteristics related to SLE were variable, along with certain common characteristics such as acanthosis in 60% of patients. Almost all the patients had antibodies against insulin receptors. The insulin doses required by the patients ranged from 450 to 25,000 U daily. Remission was achieved in 80% of the patients with a two-year follow-up. Most patients associated with late-onset SLE, like our patient, achieved metabolic control after immunosuppressive treatment. Conclusion. High insulin resistance in patients with de novo diabetes mellitus (DM) without obesity should be considered as a possible clinical manifestation of an autoimmune disease such as SLE, with a good metabolic response to the immunosuppressive management established.

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

Development of a novel diagnostic assay for insulin receptor autoantibodies based on a patient with autoimmune hypoglycaemia

Differential diagnosis of hypoglycaemia can at times be challenging for patients who appear to be well. Here we identify the case of a 66-year-old Chinese man presenting with recurrent episodes of fasting hypoglycaemia and confusion without any other manifestations. He had no personal or family history of diabetes, nor was he on any hypoglycaemic drugs. The fasting insulin levels were elevated while the C-peptide and pro-insulin levels were slightly low or normal. Antibodies against insulin were negative and levels of insulin-like growth factors were normal. A series of imaging diagnosis excluded the presence of insulinoma or ectopic insulin-secreting neuroendocrine tumor. Ultimately, insulin receptor autoantibodies (IRAb) were detected by both immunoprecipitation assay and enzyme-linked immunosorbent assay (ELISA) developed in house. In a cell study, the immunoglobulins isolated from this patient exerted insulin-like effects on stimulation of post-insulin receptor signaling and glucose uptake as well as inhibited ¹²⁵I-insulin binding with insulin receptors. Collectively, this patient was diagnosed with IRAb-induced autoimmune hypoglycaemia. Although this patient had no obvious immune disorders, several autoantibodies were identified in his plasma samples, suggesting the patient might have mild aberrant autoimmunity and therefore generated IRAb. IRAb-related disease is uncommon and possibly underdiagnosed or missed due to the lack of simple detection methods for IRAb. Our in-house user-friendly ELISA kit provides a valuable tool for diagnosis of this disease.

Case report: Successful combination therapy with double-filtration plasmapheresis and rituximab under the condition of the use of a sensor-augmented pump for type B insulin resistance syndrome

Type B insulin resistance syndrome (TBIR) is a rare disease characterized by refractory diabetes due to severe insulin resistance caused by anti-insulin receptor autoantibodies, and a standard treatment regimen for TBIR has not been established, leading to therapeutic difficulties and high mortality. Since TBIR is known to be associated with autoimmune diseases such as systemic lupus erythematosus (SLE), glucocorticoids are often used as key immunosuppressive agents. However, glucocorticoids have the potential to exacerbate the pathophysiology of TBIR by worsening insulin sensitivity, which leads to hyperglycemia and muscle wasting. Here, we report a case history of a 66-year-old man who was diagnosed as having TBIR in combination with SLE and Sjögren's syndrome with marked hyperglycemia, ketosis, and muscle wasting. He was successfully treated with combination therapy of double-filtration plasmapheresis (DFPP) and administration of the anti-CD20 monoclonal antibody rituximab without induction of glucocorticoid therapy while using a sensor-augmented insulin pump (SAP) to prevent hypoglycemia. Remission of diabetes was achieved without severe hypoglycemic events and his circulating insulin receptor antibodies became negative after seven months of initiation of these treatments. Based on the successful clinical courses of this case, our report suggests the possibility of an effective therapeutic regimen with DFPP and rituximab under the condition of the use of an SAP for a patient with TBIR without induction of glucocorticoids.

Severe insulin resistance syndromes

Severe insulin resistance syndromes are a heterogeneous group of rare disorders characterized by profound insulin resistance, substantial metabolic abnormalities, and a variety of clinical manifestations and complications. The etiology of these syndromes may be hereditary or acquired, due to defects in insulin potency and action, cellular responsiveness to insulin, and/or aberrations in adipose tissue function or development. Over the past decades, advances in medical technology, particularly in genomic technologies and genetic analyses, have provided insights into the underlying pathophysiological pathways and facilitated the more precise identification of several of these conditions. However, the exact cellular and molecular mechanisms of insulin resistance have not yet been fully elucidated for all syndromes. Moreover, in clinical practice, many of the syndromes are often misdiagnosed or underdiagnosed. The majority of these disorders associate with an increased risk of severe complications and mortality; thus, early identification and personalized clinical management are of the essence. This Review aims to categorize severe insulin resistance syndromes by disease process, including insulin receptor defects, signaling defects, and lipodystrophies. We also highlight several complex syndromes and emphasize the need to identify patients, investigate underlying disease mechanisms, and develop specific treatment regimens.

Successful remission of type B insulin resistance syndrome without rituximab in an elderly male

SUMMARY

Type B insulin resistance syndrome (TBIR) is a rare autoimmune disease caused by antibodies against the insulin receptor. It should be considered in patients with dysglycaemia and severe insulin resistance when other more common causes have been ruled out. We report a case of a 72-year-old male with a 4-year history of type 2 diabetes who presented with hypercatabolism, vitiligo, acanthosis nigricans, and hyperglycaemia resistant to massive doses of insulin (up to 1000 U/day). Detection of anti-insulin receptor antibodies confirmed TBIR. The patient received six pulses of methylprednisolone and daily treatment with cyclophosphamide for 6 months. Response to treatment was evident after the fourth pulse of methylprednisolone, as indicated by weight gain, decreased glycosylated haemoglobin and decreased requirement of exogenous insulin that was later discontinued due to episodes of hypoglycaemia. Remission was eventually achieved and the patient is currently asymptomatic, does not require insulin therapy, has normal glycaemia and is awaiting initiation of maintenance therapy with azathioprine. Thus, TBIR remitted without the use of rituximab. This case highlights the importance of diagnosis and treatment in a timely fashion, as well as the significance of clinical features, available laboratory findings and medication. Large controlled studies are required to standardise a therapeutic protocol, particularly in resource-constrained settings where access to rituximab is limited.

LEARNING POINTS

Type B insulin resistance syndrome is a rare autoimmune disorder that should be considered in patients with dysglycaemia, severe insulin resistance and a concomitant autoimmune disease. Serological confirmation of antibodies against the insulin receptor is not necessary in all cases due to the high associated mortality without timely treatment. Although there is no standardised immunosuppressive treatment, a protocol containing rituximab, cyclophosphamide and steroids has shown a significant reduction in previously reported mortality rates. The present case, reports successful remission in an atypical patient using cyclophosphamide and methylprednisolone, which is an effective therapy in countries in which rituximab is not covered by health insurance. When there is improvement in the hypercatabolic phase, the insulin dose should be reduced and/or discontinued to prevent hypoglycaemia; a mild postprandial hyperglycaemic state should be acceptable.