Autoimmune hypoglycemia in a patient with characterization of insulin receptor autoantibodies

Systematic Review-Type B Insulin Resistance With Isolated Hypoglycemia and Suppressed Insulin

OBJECTIVE

Type B insulin resistance syndrome is a rare autoimmune disorder affecting glucose homeostasis, characterized by serum autoantibodies to the insulin receptor (AIRAbs). Patients typically present with severe insulin resistance. A mixed hyper- and hypoglycemia phenotype may also occur, as may isolated hypoglycemia. The classic biochemical pattern comprises elevated insulin levels despite hypoglycemia; however, a small proportion of cases demonstrate "isolated hypoglycemia with low insulin." The primary objectives of this systematic review were to identify the clinical characteristics and outcome of this subgroup.

DESIGN

Systematic review of cases with hypoglycemia with suppressed insulin. Exclusions: hyperglycemia, elevated insulin, AIRAbs not confirmed.

METHODS

PubMed, Medline, and Embase databases were searched up until February 2023 and complemented by manual citation search. The Joanna Briggs Institute critical appraisal checklist for case reports was used to assess bias.

RESULTS

A total of 5342 articles were identified after duplicate removal. Eleven, all case reports, met all inclusion criteria and were included. Cases belonging to this subgroup were more diverse in sex, age, and ethnicity when compared with type B insulin resistance as a whole. Of the 11 cases, 3 developed lymphoma. High-dose corticosteroid therapy appeared to be effective therapy for the hypoglycemia, with often rapid response.

CONCLUSIONS

Isolated hypoglycemia with low insulin forms a rare subgroup of type B insulin resistance. These patients lack the common characteristics of hyperinsulinemic hypoglycemia and hyperglycemia/insulin resistance. Furthermore, while coexisting autoimmune disease is commonly observed, there is potentially an association with aggressive lymphoma, the onset of which may be delayed.

Type B insulin resistance syndrome: a systematic review

A literature review on the clinical, laboratory, and treatment features of type B insulin resistance syndrome (TBIRS). Data from PubMed, the Virtual Health Library and Cochrane database were selected and analyzed using the REDCap application and R statistical program. From 182 papers, 65 were selected, which assessed 119 clinical cases, 76.5% in females and 42.9% in African-Americans, with an average age of 44 years. A common feature of TBIRS is co-occurrence of autoimmune diseases, such as systemic lupus erythematosus (most frequently reported). Hyperglycemia of difficult control was the mostly reported condition. Tests for anti-insulin receptor antibodies were positive in 44.2% of the cases. Disease management comprised fractional diet, insulin therapy (maximum dose given was 57 600 IU/day), plasmapheresis and immunosuppression with several classes of drugs, mainly glucocorticoids. Remission occurred in 69.7% of cases, in 30.3% of these spontaneously. The mortality rate was 15.38%. There was an inverse relationship between anti-insulin antibodies and remission (p = 0.033); and a positive correlation between combined immunosuppressive therapy and remission (p = 0.002). Relapse occurred in 7.6% of the cases. This rare syndrome has difficult-to-control diabetes, even with high doses of insulin, and it is usually associated with autoimmune diseases. Therapeutic advances using immunomodulatory therapy have led to significant improvements in the rate of remission.

Insulin autoimmune syndrome

SUMMARY

Insulin autoimmune syndrome (Hirata's disease) is a disorder caused by development of autoantibodies to insulin and manifested by hypoglycaemic syndrome. The overwhelming majority of physicians do not include it in the differential diagnosis of hypoglycaemic states because of a misconception of an extremely low prevalence of this condition. This results in unnecessary drug therapy and unjustified surgical interventions in patients that otherwise would be successfully treated conservatively. This disease is strongly associated with certain alleles of the HLA gene. In most cases, this condition develops in predisposed individuals taking drugs containing sulfhydryl groups. Formation of autoantibodies to insulin may be observed in patients with other autoimmune disorders, as well as in those with multiple myeloma or monoclonal gammopathy of undetermined significance. This paper presents the first Russian case report of insulin autoimmune syndrome in an adult patient.

LEARNING POINTS

Insulin autoimmune syndrome, Hirata's disease, anti-insulin antibodies, and hypoglycaemia.

Combined Immunosuppressive Therapy Induces Remission in Patients With Severe Type B Insulin Resistance: A Prospective Cohort Study

OBJECTIVE

Type B insulin resistance due to autoantibodies against the insulin receptor is characterized by diabetes refractory to massive doses of insulin, severe hypercatabolism, hyperandrogenism, and a high mortality rate. We analyzed the efficacy of combined immunosuppressive therapy in the management of this extreme form of diabetes.

RESEARCH DESIGN AND METHODS

We performed a prospective cohort study including patients with confirmed insulin receptor autoantibodies, monitored for median 72 months (25th, 75th interquartile range 25, 88), and treated with rituximab, high-dose pulsed steroids, and cyclophosphamide until remission, followed by maintenance therapy with azathioprine. Remission was defined as the amelioration of the hyperglycemia and discontinuation of insulin and/or normalization of hyperandrogenemia.

RESULTS

All data are given as median (25th, 75th interquartile range). Twenty-two patients aged 42 (25, 57) years, 86.4% women, fulfilled inclusion criteria. At baseline, fasting glucose was 307 (203, 398) mg/dL, HbA_1c was 11.8% (9.7, 13.6), total testosterone (women) was 126 (57, 571) ng/dL (normal 8-60), and daily insulin requirement was 1,775 (863, 2,700) units. After 5 (4, 6.3) months, 86.4% (19 of 22) of patients achieved remission, documented by discontinuation of insulin in all patients, normal fasting glucose of 80 (76, 92) mg/dL, HbA_1c of 5.5% (5.2, 6), and testosterone (women) of 28 (20, 47) ng/dL. During follow-up of 72 (25, 88) months, 13.6% (3 of 22) of patients developed disease recurrence, occurring 24 (22, 36) months after initial remission, which responded to repeated therapy. None of the patients died.

CONCLUSIONS

Combined immunosuppressive therapy has changed the natural history of this disease, from 54% mortality to a curable form of diabetes and, as such, should be recommended in patients with type B insulin resistance.

Unique pharmacology of a novel allosteric agonist/sensitizer insulin receptor monoclonal antibody

Objective

Insulin resistance is a key feature of Type 2 Diabetes (T2D), and improving insulin sensitivity is important for disease management. Allosteric modulation of the insulin receptor (IR) with monoclonal antibodies (mAbs) can enhance insulin sensitivity and restore glycemic control in animal models of T2D.

Methods

A novel human mAb, IRAB-A, was identified by phage screening using competition binding and surface plasmon resonance assays with the IR extracellular domain. Cell based assays demonstrated agonist and sensitizer effects of IRAB-A on IR and Akt phosphorylation, as well as glucose uptake. Lean and diet-induced obese mice were used to characterize single-dose in vivo pharmacological effects of IRAB-A; multiple-dose IRAB-A effects were tested in obese mice.

Results

In vitro studies indicate that IRAB-A exhibits sensitizer and agonist properties distinct from insulin on the IR and is translated to downstream signaling and function; IRAB-A bound specifically and allosterically to the IR and stabilized insulin binding. A single dose of IRAB-A given to lean mice rapidly reduced fed blood glucose for approximately 2 weeks, with concomitant reduced insulin levels suggesting improved insulin sensitivity. Phosphorylated IR (pIR) from skeletal muscle and liver were increased by IRAB-A; however, phosphorylated Akt (pAkt) levels were only elevated in skeletal muscle and not liver vs. control; immunochemistry analysis (IHC) confirmed the long-lived persistence of IRAB-A in skeletal muscle and liver. Studies in diet-induced obese (DIO) mice with IRAB-A reduced fed blood glucose and insulinemia yet impaired glucose tolerance and led to protracted insulinemia during a meal challenge.

Conclusion

Collectively, the data suggest IRAB-A acts allosterically on the insulin receptor acting non-competitively with insulin to both activate the receptor and enhance insulin signaling. While IRAB-A produced a decrease in blood glucose in lean mice, the data in DIO mice indicated an exacerbation of insulin resistance; these data were unexpected and suggested the interplay of complex unknown pharmacology. Taken together, this work suggests that IRAB-A may be an important tool to explore insulin receptor signaling and pharmacology.

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A novel anti-insulin receptor monoclonal antibody (IRAB-A) was identified that has both agonist and sensitizing activities.

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IRAB-A increases the receptor's affinity for insulin by binding to an allosteric site and does not compete with insulin.

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Mice injected once with IRAB-A show improved glycemia and reduced insulinemia, indicative of enhanced insulin sensitivity.

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In diet induced obese mice, the insulin sensitizing effect of IRAB-A appears to depend on the degree of insulin resistance.

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Chronic treatment of obese mice showed mixed effects on glucose homeostasis under normal fed or meal challenged conditions.

Immunosuppressive Therapy in Treatment of Refractory Hypoglycemia in Type B Insulin Resistance: A Case Report

Type B insulin resistance is a rare syndrome characterized by fluctuating glucose levels (ranging from hyperglycemia with extreme insulin resistance to intractable hypoglycemia without exogenous insulin administration), high serum insulin levels, and insulin receptor autoantibodies. Most cases occur in the African American population in association with other underlying autoimmune systemic diseases. Treatments with high-dose steroids, immunosuppressants, and plasmapheresis have been used, with variable outcomes, in patients without spontaneous remission. We report the case of a 60-year-old African American woman with history of systemic lupus erythematosus presenting with extreme fluctuations in glucose levels, ranging from severe hyperglycemia to refractory hypoglycemia, with high serum concentration of insulin in both phases. Her presentation and phenotype were very similar to those seen in known cases of type B insulin resistance associated with insulin receptor antibodies. Treatment in other reported cases used a combination of high-dose steroids and immunosuppressants. We tried high-dose steroids, azathioprine, and intravenous immunoglobulins, which resulted in improvement and barely detectable insulin receptor antibody. We present a case of type B insulin resistance with abnormally low titers of insulin receptor antibodies despite a typical clinical course and response. Future research is needed to improve diagnosis and treatment in this rare disease.

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.

The treatment of hyperinsulinemic hypoglycaemia in adults: an update

BACKGROUND

Treatment of hyperinsulinemic hypoglycaemia (HH) is challenging due to the rarity of this condition and the difficulty of differential diagnosis. The aim of this article is to give an overview of the recent literature on the management of adult HH.

METHODS

A search for reviews, original articles, original case reports between 1995 and 2016 in PubMed using the following keywords: hyperinsulinemic hypoglycaemia, insulinoma, nesidioblastosis, gastric bypass, autoimmune hypoglycaemia, hyperinsulinism, treatment was performed.

RESULTS

One hundred and forty articles were selected and analysed focusing on the most recent treatments of HH.

CONCLUSIONS

New approaches to treatment of HH are available including mini-invasive surgical techniques and alternative local-regional ablative therapy for benign insulinoma and everolimus for malignant insulinoma. A correct differential diagnosis is of paramount importance to avoid unnecessary surgical operations and to implement the appropriate treatment mainly in the uncommon forms of HH, such as nesidioblastosis and autoimmune hypoglycaemia.

Type B insulin resistance syndrome

PURPOSE OF REVIEW

To review the epidemiology, pathophysiology, clinical features, and management of type B insulin resistance syndrome.

RECENT FINDINGS

Type B insulin resistance syndrome is a rare disorder caused by autoantibodies to the insulin receptor. This disorder is most frequently reported in middle-aged black women and is invariably associated with other autoimmune diseases. Typically, refractory transient hyperglycemia and extreme insulin resistance are the cardinal features, but hypoglycemia may also occur. Traditionally, the high reported mortality rate was typically attributed to the hypoglycemia. There is no well standardized treatment regimen. However, recent therapeutic advances with combination immunomodulatory therapy have led to significant reported improvements in hypoglycemia-associated mortality and durability of remission.

SUMMARY

We review the literature on the pathophysiology and clinical features of type B insulin resistance syndrome and highlight the complexities and recent advances in the management of this disorder.

Antibody-Mediated Insulin Resistance: When Insulin and Insulin Receptor Act as Autoantigens in Humans

We report the case of a patient with diabetes presenting a severe insulin-resistance syndrome due to the production of insulin autoantibodies by a lymphocytic lymphoma. We describe the various mechanisms leading to the production of insulin autoantibodies and insulin receptor autoantibodies and review the therapeutic possibilities.

Type B insulin-resistance syndrome presenting as autoimmune hypoglycemia, associated with systemic lupus erythematosus and interstitial lung disease

We describe an unusual case of systemic lupus erythematosus with pulmonary manifestations presenting as hypoglycemia due to anti-insulin receptor antibodies. A 38-year-old female suffered an episode of unconsciousness and was admitted to hospital where her blood glucose was found to be 18 mg/dL. During the hypoglycemic episode, her serum insulin level was inappropriately high (2,207.1 pmol/L; normal range, 18 to 173) and C-peptide level was elevated (1.7 nmol/L; normal range, 0.37 to 1.47). Further blood tests revealed the presence of antinuclear antibodies, anti-double-stranded DNA antibodies, and anti-Ro/SSA, anti-La/SSB, anti-ribonucleoprotein, and anti-insulin receptor antibodies. A computed tomography scan of the abdomen, aimed at tumor localization, such as an insulinoma, instead revealed ground-glass opacities in both lower lungs, and no abnormal finding in the abdomen. For a definitive diagnosis of the lung lesion, video-associated thoracoscopic surgery was performed and histopathological findings showed a pattern of fibrotic non-specific interstitial pneumonia.

Fulminant Type 1 diabetes in a pregnant woman as an initial manifestation of the insulin autoimmune syndrome

Fulminant Type 1 diabetes is a subtype of Type 1 diabetes characterized by (1) abrupt onset of diabetes, (2) very short duration of hyperglycaemia with mildly elevated HbA(1c) (< 69 mmol/mol, 8.5%), (3) rapid progression to diabetic ketoacidosis, (4) very low C-peptide level, and (5) often associated with elevated serum pancreatic enzymes, and absence of diabetes-related autoantibodies. We encountered a case of fulminant Type 1 diabetes that developed with an initial manifestation of the insulin autoimmune syndrome and rapidly progressed to diabetic ketoacidosis during pregnancy. A 31-year-old Korean woman presented with recurrent sudden onset of sweating and change of consciousness during sleep at 19 weeks gestation. During a 72-h fasting test, hypoglycaemia (1.72 mmol/l) occurred at 4 h after the start of the test. At that time, there was a high insulin level (370.2 μU/ml), a paradoxically low C-peptide level (0.01 nmol/l) and a positive insulin autoantibody test. An oral glucose tolerance test revealed postprandial hyperglycaemia. She was initially diagnosed as the insulin autoimmune syndrome. On the day 5 of admission, she developed diabetic ketoacidosis. Her HbA(1c) was 62 mmol/mol (7.8%). The rapid progression of diabetic ketoacidosis altered the diagnosis to fulminant Type 1 diabetes. This case differed from typical fulminant Type 1 diabetes because it presented with hypoglycaemia, and positive insulin and anti-phospholipid antibody tests. Her HLA typing was HLA-DQA1*0302, 0501, HLA-DRB1*0301 (DR3), 0901(DR9). Her glucose level was subsequently very well controlled with multiple insulin injections and she successfully delivered a healthy baby.

Treatment of recurrent hypoglycemia with plasmapheresis and steroid in nondiabetic patient

We recently encountered a 35-year old man who suffered from frequent hypoglycemia. His blood test revealed the presence of high and suppressed level of insulin with supressed C-peptide levels, hypothalamic-pituitary axis was normal response in hypoglycemia and negative for anti-insulin antibody. Endocrinological and imaging data eliminated the possibility of insulinoma. His symptoms responded well to the therapy of prednisolone (60 mg/day) and plasmapheresis. We followed up the patient over the subsequent 6 months without remarkable lesions. He has had no further recurrences of hypoglycemia. We believe that the antiinsulin receptor antibody might have induced hypoglycemia in this patient.

The effect of hyperglycemia and hypoglycemia on glucose transport and expression of glucose transporters in human lymphocytes B and T: an in vitro study

Glucose transport in lymphocytes is regulated by many agents. It is interesting if only changing glucose concentrations in environment involves the impact on glucose uptake. The aims of this study were to investigate the impact of changing glucose concentrations in medium on deoxy-d-glucose uptake and what these conditions impact on the percent of cells with expression of chosen glucose transporters in human lymphocytes B and T. Isolated lymphocytes B and T obtained from healthy subject were cultivated in different concentrations of glucose. The experiments were carried out using tritium labeled deoxy-d-glucose and flow cytometry. In comparison to normoglycemia, hyperglycemia impairs the uptake of deoxy-d-glucose more than hypoglycemia. Lymphocytes B manifest significantly lower uptake of deoxy-d-glucose than lymphocytes T. Lymphocytes incubated in hyperglycemic and hypoglycemic medium show lower percent cells with expression of GLUT 1 and GLUT 3, and higher percent cells with expression of GLUT 4. The incubation of lymphocytes in hyperglycemic and hypoglycemic medium does not stimulate translocation of glucose transporters 3 and 4 to plasma membrane. Study shows that a change in concentration of glucose in incubation environment influence intracellular expression of glucose transporters in a significant part of lymphocytes B and T.