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.

Comparative assessment of immunogenicity of recombinant insulin Aspart from BioGenomics and its originator NovoRapid® in adult patients with type 2 diabetes mellitus.

OBJECTIVES: To assess and compare the immunogenicity of recombinant Insulin Aspart [manufactured by BioGenomics Limited (BGL-ASP)] with its originator NovoRapid® (manufactured by Novo Nordisk) in adult patients with type 2 diabetes mellitus. RESEARCH DESIGN AND METHODS: BGL-IA-CTP301 study was a randomized, open label, parallel group, multicenter phase-III clinical study to compare the efficacy and safety of recombinant Insulin Aspart 100 U/mL [manufactured by BioGenomics Limited (BGL-ASP)] with its reference medicinal product (RMP); NovoRapid® [manufactured by Novo Nordisk], in adult patients with Type 2 diabetes mellitus (T2DM). The primary objective of the study was to compare the immunogenicity of BGL-ASP and RMP; NovoRapid® in patient serum samples collected from phase-III clinical study. Immunogenicity was studied as the incidence of patients positive for anti-insulin Aspart (AIA) antibodies, developed against BGL-ASP/RMP at baseline, end of 12 week and end of 24 week of the treatment period. The changes in incidence of patients positive for AIA antibodies post-baseline were also studied to assess and compare the treatment-emergent antibody response (TEAR) between the treatment groups (BGL-ASP and RMP). Statistical evaluation was done by Fisher's exact test to compare the overall incidence of patients positive for AIA antibodies and the TEAR positives observed post-baseline in both the treated groups. An in-vitro neutralizing antibody assay (Nab assay) was also performed to study the effect of AIA antibodies in neutralizing the biological activity/metabolic function of the insulin. The neutralizing potential of AIA was studied by its effect on %glucose uptake. We also evaluated the association between AIA antibody levels and its impact on biological activity by studying the correlation between them. RESULTS: Analysis of immunogenicity data suggested that the percentage of patients positive for AIA antibodies until week 24 was similar and comparable in both the treatment groups, BGL-ASP and RMP; NovoRapid®. The changes in incidence of patients positive for AIA post-baseline in terms of TEAR positives were also similar and comparable between the treatment groups. The results of the Nab assay with confirmed positive AIA samples from BGL-ASP- and RMP-treated groups did not have any negative impact on %glucose uptake by the cells in Nab assay, confirming the absence of neutralizing antibodies in both the treatment groups. The correlation studies also showed absence of association between AIA antibody levels and percentage glucose uptake in both BGL-ASP and RMP-NovoRapid® treatment groups. CONCLUSIONS: The immunogenicity assessment based on the overall incidence of patients positive for AIA, changes in incidence of patients positive for AIA post-baseline, TEAR rates and absence of neutralizing antibodies, were found to be apparently similar and comparable in both the treatment groups (BGL-ASP and RMP). We conclude from our studies that the immunogenicity of BGL-ASP is similar and comparable to RMP and the observed immunogenicity in terms of anti-insulin Aspart antibody levels had no impact on the biological activity of insulin.

Type B Insulin Resistance Syndrome: A Rare Cause of Hypoglycemia.

We describe a case of a Black female patient with a history of type 2 diabetes mellitus and systemic lupus erythematosus, who had a subacute onset of severe hypoglycemia that persisted after cessation of insulin therapy. Biochemical testing revealed hyperinsulinemic hypoglycemia, normal serum triglycerides, and high-normal serum adiponectin levels. Abdominal imaging demonstrated an 11-mm cystic pancreatic lesion. Her clinical history and biochemical test results raised suspicion for type B insulin resistance syndrome (TBIRS), which was confirmed on anti-insulin receptor antibody testing. The patient's hypoglycemia was managed with dietary modification therapy and continuous glucose monitoring. The severity and frequency of hypoglycemic episodes decreased spontaneously. We describe TBIRS and its uncommon hypoglycemic presentation, analyze factors that put TBIRS among the differential diagnosis, and discuss the treatment of TBIRS-associated hypoglycemia.

In vivo relationship between bound and free insulin in patients with diabetes having anti-insulin antibodies.

Objective: The Scatchard plot of anti-insulin antibodies is curvilinear, indicating heterogeneity in binding sites. However, the relationship between bound insulin (B) and free insulin (F) in patients with anti-insulin antibodies has not yet been elucidated. This study aimed to determine this relationship. Methods: We studied two insulin-treated patients with diabetes who had high titers of anti-insulin antibodies. The B and F levels were measured using daily blood samples. Assuming that the law of mass action is applicable to the reactions between insulin and anti-insulin antibody forms, we plotted the bound-to-free ratio (B/F) vs. B using patient data. We also performed an equilibrium binding assay in vitro. Results: Some of the B/F vs. B plots of the daily variation showed an approximately linear relationship, while the Scatchard plots of in vitro data became curvilinear. Conclusion: Our study suggests that the one-site (high-affinity site) of anti-insulin antibodies accounts, for the most part, for insulin pharmacokinetics within physiological insulin concentrations. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-023-00641-1.

Development and Characterization of Guinea Pig Anti-Insulin Polyclonal Antibody.

Development and characterization of guinea pig anti-insulin polyclonal antibody against a target-specific insulin antigen. In India, an insulin immunogenicity kit for detecting insulin antibodies (neutralizing Nab) is an unmet medical need for diabetic patient's routine diagnosis. Type 1 diabetics rely on insulin injections daily basis for survival; if the body develops anti-insulin antibodies and neutralizes the exogenous recombinant insulin, glucose control is lost, and the patient eventually dies. Antibodies are excellent diagnostic reagents due to the specificity and sensitivity they provide in recognizing specific and unique target antigens. The paper describes the use of insulin as a target antigen and the development of target (insulin) specific antibodies in guinea pigs for use as a positive control for immunogenicity kit validation. Anti-insulin polyclonal antibody was raised against insulin in the Dunkin Hartley guinea pigs host. Anti-insulin antibody titer of all bleeds from four animals was tested using an indirect ELISA assay format. All four animals responded to the target-specific antigen but only one animal (#4) responded with a high-affinity antibody titer. The hyperimmune sera were purified using a protein A column. The purified anti-insulin antibody was characterized through SDS Page and western blot. The specificity, reactivity, and antibody binding efficiency were confirmed through immunoassays. Guinea pig anti-insulin polyclonal antibody developed in this study showed good specificity, reactivity, and efficiency in the immunoassays. This paper describes the development and characterization of anti-insulin antibodies for use as a control in developing a user-friendly insulin immunogenicity kit.

Diagnosis and treatment of anti-insulin antibody-mediated labile glycaemia in insulin-treated diabetes.

AIMS: Anti-insulin antibodies in insulin-treated diabetes can derange glycaemia, but are under-recognised. Detection of significant antibodies is complicated by antigenically distinct insulin analogues. We evaluated a pragmatic biochemical approach to identifying actionable antibodies, and assessed its utility in therapeutic decision making. METHODS: Forty people with insulin-treated diabetes and combinations of insulin resistance, nocturnal/matutinal hypoglycaemia, and unexplained ketoacidosis were studied using broad-specificity insulin immunoassays, polyethylene glycol (PEG) precipitation and gel filtration chromatography (GFC) with or without ex vivo insulin preincubation. RESULTS: Twenty-seven people had insulin immunoreactivity (IIR) below 3000 pmol/L that fell less than 50% after PEG precipitation. Insulin binding by antibodies in this group was low and judged insignificant. In 8 people IIR was above 3000 pmol/L and fell by more than 50% after PEG precipitation. GFC demonstrated substantial high molecular weight (HMW) IIR in 7 of these 8. In this group antibodies were judged likely significant. In 2 people immunosuppression was introduced, with a good clinical result in one but only a biochemical response in another. In 6 people adjustment of insulin delivery was subsequently informed by knowledge of underlying antibody. In a final group of 5 participants IIR was below 3000 pmol/L but fell by more than 50% after PEG precipitation. In 4 of these GFC demonstrated low levels of HMW IIR and antibody significance was judged indeterminate. CONCLUSIONS: Anti-insulin antibodies should be considered in insulin-treated diabetes with unexplained glycaemic lability. Combining immunoassays with PEG precipitation can stratify their significance. Antibody depletion may be beneficial, but conservative measures often suffice.

Phytosome Supplements for Delivering Gymnema inodorum Phytonutrients to Prevent Inflammation in Macrophages and Insulin Resistance in Adipocytes.

Gymnema inodorum (GI) is a leafy green vegetable found in the northern region of Thailand. A GI leaf extract has been developed as a dietary supplement for metabolic diabetic control. However, the active compounds in the GI leaf extract are relatively nonpolar. This study aimed to develop phytosome formulations of the GI extract to improve the efficiencies of their phytonutrients in terms of anti-inflammatory and anti-insulin-resistant activities in macrophages and adipocytes, respectively. Our results showed that the phytosomes assisted the GI extract's dispersion in an aqueous solution. The GI phytocompounds were assembled into a phospholipid bilayer membrane as spherical nanoparticles about 160-180 nm in diameter. The structure of the phytosomes allowed phenolic acids, flavonoids and triterpene derivatives to be embedded in the phospholipid membrane. The existence of GI phytochemicals in phytosomes significantly changed the particle's surface charge from neutral to negative within the range of -35 mV to -45 mV. The phytosome delivery system significantly exhibited the anti-inflammatory activity of the GI extract, indicated by the lower production of nitric oxide from inflamed macrophages compared to the non-encapsulated extract. However, the phospholipid component of phytosomes slightly interfered with the anti-insulin-resistant effects of the GI extract by decreasing the glucose uptake activity and increasing the lipid degradation of adipocytes. Altogether, the nano-phytosome is a potent carrier for transporting GI phytochemicals to prevent an early stage of T2DM.

Insulin antibodies are prevalent in adults with type 1 diabetes referred for islet cell transplantation and are modified by islet transplantation and immunosuppression: an Australian experience.

We have analysed insulin antibodies in 149 adults with type 1 diabetes and 2859 people without diabetes. We have determined that insulin antibody levels are higher in adults with, versus without, diabetes and that the levels are falling, and more patients are becoming antibody-negative post islet cell transplantation.

The evaluation of pancreas β-cell autoantibodies in non-diabetic COVID-19 patients

ABSTRACT Objective: This study aims to evaluate potential pancreas endocrine damage due to SARS-CoV-2 by measuring β-cell autoantibodies in COVID-19 patients. Subjects and methods: Between June and July 2020, 95 inpatients with a positive COVID-19 test result after polymerase-chain-reaction (PCR) and who met the inclusion criteria were enrolled in our study. Laboratory parameters that belong to glucose metabolism and β-cell autoantibodies, including anti-islet, anti-glutamic acid decarboxylase, and anti-insulin autoantibodies, were measured. β-cell autoantibodies levels of the patients were measured during COVID-19 diagnosis. Positive results were reevaluated in the 3rd month of control. Results: In the initial evaluation, 4 (4.2%) patients were positive for anti-islet autoantibody. Only one (1.1%) patient was positive for anti-glutamic acid decarboxylase autoantibody. No patient had positive results for anti-insulin autoantibody. FPG, HbA1c, and C-peptide levels were similar in patients who were split into groups regarding the initial positive or negative status of anti-islet and anti-GAD autoantibodies (p>0.05). In the 3rd month after the initial measurements, anti-islet autoantibody positivity of 2 (50%) of 4 patients and anti-glutamic acid decarboxylase positivity of 1 (100%) patient were persistent. Finally, 3 (3.1%) patients in the whole group were positive for anti-islet autoantibody in the 3rd month of control. No difference was determined between the initial and the 3rd month of parameters of glucose metabolism. Conclusion: Following an ongoing autoantibody positivity in the present study brings the mind that SARS-CoV-2 may be responsible for the diabetogenic effect. Clinicians should be aware of autoantibody-positive DM as a potential autoimmune complication in patients with SARS-CoV-2.

The evaluation of pancreas ß-cell autoantibodies in non-diabetic COVID-19 patients.

Objective: This study aims to evaluate potential pancreas endocrine damage due to SARS-CoV-2 by measuring ß-cell autoantibodies in COVID-19 patients. Subjects and methods: Between June and July 2020, 95 inpatients with a positive COVID-19 test result after polymerase-chain-reaction (PCR) and who met the inclusion criteria were enrolled in our study. Laboratory parameters that belong to glucose metabolism and ß-cell autoantibodies, including anti-islet, anti-glutamic acid decarboxylase, and anti-insulin autoantibodies, were measured. ß-cell autoantibodies levels of the patients were measured during COVID-19 diagnosis. Positive results were reevaluated in the 3rd month of control. Results: In the initial evaluation, 4 (4.2%) patients were positive for anti-islet autoantibody. Only one (1.1%) patient was positive for anti-glutamic acid decarboxylase autoantibody. No patient had positive results for anti-insulin autoantibody. FPG, HbA1c, and C-peptide levels were similar in patients who were split into groups regarding the initial positive or negative status of anti-islet and anti-GAD autoantibodies (p>0.05). In the 3rd month after the initial measurements, anti-islet autoantibody positivity of 2 (50%) of 4 patients and anti-glutamic acid decarboxylase positivity of 1 (100%) patient were persistent. Finally, 3 (3.1%) patients in the whole group were positive for anti-islet autoantibody in the 3rd month of control. No difference was determined between the initial and the 3rd month of parameters of glucose metabolism. Conclusion: Following an ongoing autoantibody positivity in the present study brings the mind that SARS-CoV-2 may be responsible for the diabetogenic effect. Clinicians should be aware of autoantibody-positive DM as a potential autoimmune complication in patients with SARS-CoV-2.

Influence of Insulin Receptor Single Nucleotide Polymorphisms on Glycaemic Control and Formation of Anti-Insulin Antibodies in Diabetes Mellitus.

Single nucleotide polymorphisms (SNPs) in insulin and insulin receptor genes may influence the interaction between the two molecules, as may anti-insulin antibodies (IAs), commonly found in patients with type 1 diabetes mellitus (T1D) or type 2 diabetes mellitus (T2D) treated with exogenous insulin. We examined the impact of two SNPs in the human insulin gene (INS), rs3842752 and rs689, and two in the insulin receptor gene (INSR) rs2245649 and rs2229429, on disease susceptibility, glycaemic control, and IAs formation in 100 T1D patients and 101 T2D patients treated with insulin. 79 individuals without diabetes were typed as healthy controls. The minor alleles of rs3842752 and rs689 in INS protected against T1D (OR: 0.50, p = 0.01 and OR: 0.44; p = 0.002, respectively). The minor alleles of both rs2245649 and rs2229429 in INSR were risk factors for poor glycaemic control (HbA1c ≥ 80 mmol/mol) in T1D (OR: 5.35, p = 0.009 and OR: 3.10, p = 0.01, respectively). Surprisingly, the minor alleles of rs2245649 and rs2229429 in INSR associated strongly with the absence of IAs in T1D (OR = 0.28, p = 0.008 and OR = 0.30, p = 0.002, respectively). In conclusion, the minor alleles of the investigated INS SNPs protect against T1D, and the minor alleles of the investigated INSR SNPs are associated with poor glycaemic control and the absence of IAs in T1D.

Autoanticuerpos anti-insulina en la diabetes tipo 1 / Anti-insulin autoantibodies in type 1 diabetes

Introducción: Los autoanticuerpos anti-insulina (AAI) representan un marcador serológico de la diabetes tipo 1 (DT1). El significado clínico de los AAI aún no ha sido determinado en la población cubana. Objetivo: Determinar el valor clínico de AAI en pacientes con DT1. Métodos: Se determinaron los niveles séricos de AAI por el ensayo inmuno-adsorbente ligado a enzima (ELISA) en 33 pacientes adultos con DT1, 78 pacientes con otras condiciones endocrinas (CEE) como diabetes tipo 2, tiroiditis de Hashimoto e hiperinsulinemia, y 49 controles normales (CN). El valor de corte se determinó con el análisis de las curvas características operativas del receptor (COR) (ROC por sus siglas en inglés). Se utilizaron pruebas no paramétricas para comparar los niveles de AAI de pacientes con DT1, CEE y CN, y determinar la correlación entre AAI y la edad. Resultados: El valor de corte óptimo de AAI para DT1 fue el índice de 1,05, con sensibilidad de 45,5 por ciento, especificidad de 81,6 por ciento, razón de verosimilitud positiva de 2,47, y razón de verosimilitud negativa de 0,67. Los niveles de AAI en DT1 (índice de 0,97) fueron significativo, más altos que los de CN (índice de 0,70; p=0,020) y los de CEE (índice de 0,63; p= 0,009). Los niveles de AAI resultaron inversamente proporcionales a la edad en pacientes diabéticos ( =-0,252; p=0,030). Conclusiones: Los pacientes con DT1 se distinguieron por niveles más altos de AAI, aunque la presencia de estos anticuerpos no fue exclusiva de DT1. Los niveles de AAI dependieron de la edad en los pacientes diabéticos(AU)

Introduction: Anti-insulin autoantibodies (AAI) represent a serological marker of type 1 diabetes (T1D). The clinical significance of AAIs has not yet been determined in the Cuban population. Objective: To determine the clinical value of AAI in patients with T1D. Methods: AAI serum levels were determined by enzyme-linked immunosorbent assay (ELISA) in 33 adult patients with T1D, 78 patients with other endocrine conditions (CEE) such as type 2 diabetes, Hashimoto's thyroiditis, and hyperinsulinemia, and 49 normal controls (CN). The cut-off value was determined by receiver operating characteristic (ROC) curve analysis. Nonparametric tests were used to compare the AAI levels of patients with T1D, CEE, and CN, and to determine the correlation between AAI and age. Results: AAI optimal cut-off value for T1D was the index of 1.05, with 45.5 percent of sensitivity, 81.6 percent specificity, 2.47 positive likelihood ratio, and 0.67 negative likelihood ratio. AAI levels in DT1 (index of 0.97) were significant, higher than those of CN (index of 0.70; p= 0.020) and CEE levels (index of 0.63; p= 0.009). AAI levels were inversely proportional to age in diabetic patients (ρ = -0.252; p=0.030). Conclusions: Patients with T1D were distinguished by AAI higher levels, although the presence of these antibodies was not exclusive to T1D. AAI levels depended on age in diabetic patients(AU)

Serious diabetic ketoacidosis induced by insulin allergy and anti-insulin antibody in an individual with type 2 diabetes mellitus.

Diabetic ketoacidosis (DKA) is one of the most serious acute metabolic complications of diabetes mellitus, and is characterized by hyperglycemia, metabolic acidosis and increased total ketone body concentrations. The main mechanism of DKA is a lack of insulin in the body. It has been reported that some immunological response is associated with insulin therapy. Herein, we report a case of serious DKA, which was induced by insulin allergy and anti-insulin antibody. This case clearly shows that DKA can be induced by insulin allergy and anti-insulin antibodies in individuals with type 2 diabetes treated with insulin. Furthermore, we should know that as the required insulin dose might be very high under severe insulin resistance and serious DKA in such cases, we should increase the insulin dose appropriately while monitoring pH, base excess and other factors.

Production of insulin antibody associated with relapsed hodgkin's lymphoma.

A 72-year-old man with type 2 diabetes mellitus with good glucose control for 20 years and maintained on oral hypoglycaemic agents was diagnosed with Hodgkin's Lymphoma (HL) and started on insulin glargine for glycaemic control. Despite increased doses of insulin, his blood glucose levels went up dramatically. The anti-insulin antibody test proved to be positive, and Scatchard plot analysis showed 2 binding sites with relatively low-affinity constants: K 1 = 0.0032, K 2 = 0.0002 (108/M); and high binding capacities: R 1 = 98.4, R 2 = 372 (10-8 M), which were compatible with the features of antibody of insulin autoimmune syndrome (IAS). However, hypoglycaemia was not noted throughout the course of treatment. Since the insulin binding ratio of the antibody decreased from 87.3% to 62% after the termination of insulin treatment, it was suggested that the antibody reacted mainly to exogenously injected insulin. Switching insulin preparations or introducing insulin secretagogues did not improve elevated blood glucose levels. The initiation of brentuximab vedotin (BV), a therapeutic agent for relapsed HL, resulted in a remarkable improvement in glycaemic control despite the absence of insulin therapy and partial remission of HL. This case suggested that HL triggered anti-insulin antibody production, which resulted in poor glycaemic control, and that BV could be a new treatment option for autoimmune diseases associated with HL. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-021-00550-1.

Comparative study on the therapeutic effects of bone marrow mesenchymal stem cells versus platelet rich plasma on the pancreas of adult male albino rats with streptozotocin-induced type 1 diabetes mellitus.

BACKGROUND: The optimal treatment for autoimmune type 1 diabetes mellitus (T1DM) is endogenous regeneration of the pancreatic beta-cell. This can be achieved either by transplanting bone marrow mesenchymal stem cells (BMSCs) or injecting platelet-rich plasma (PRP). Current research reviewed a T1DM model and compared the effect of BMSCs on exocrine and endocrine pancreas portions versus PRP. MATERIALS AND METHODS: Rats were divided into four groups: Control group, Diabetic group (single streptozotocin dose 60 mg/kg IP), Diabetic + PRP group (PRP, 0.5 mL/kg SC twice weekly/4 weeks given to diabetic rats) and Diabetic + BMSCs group (1 mL of PKH26 labelled MSCs suspension in buffer phosphate solution, 3 × 106 cells/mL IV to diabetic rats). Glucose, amylase and lipase levels were calculated and pancreases were designed for light, electron microscopic, immunohistochemistry, morphometry and statistical analysis. RESULTS: Diabetic rats exhibited elevated glucose, decreased amylase and lipase compared to control rats. In addition, variable histological degenerative changes in the form of congested blood vessels have been identified with a significant increase in the mean area percentage of collagen, a significant decrease in the diameter of the islets, the number of cells in the islets of Langerhans and the number of zymogen granules. Ultrastructural findings exhibited distorted Golgi apparatus morphology, degenerated mitochondria, pyknotic nuclei, and few secretory beta-cell granules. CONCLUSIONS: Administration of BMSCs to diabetic group significantly increased the number of cells and diameter of Langerhans islets and the number of zymogen granules compared to Diabetic group as well as Diabetic + PRP group. BMSCs could be considered more efficient than PRP in the treatment of type 1 diabetes.

Insulin Receptor Autoantibody-mediated Hypoglycemia in a Woman With Mixed Connective Tissue Disease.

Autoantibodies to the insulin receptor are rare and typically cause severe insulin resistance and hyperglycemia, a condition termed type B insulin resistance. Uncommonly, antibodies to the insulin receptor can cause hypoglycemia. We present the case of a woman who developed recurrent severe hypoglycemia and myopathy, was found to have insulin receptor autoantibodies and mixed connective tissue disease, and had resolution of hypoglycemia with immunosuppression. A 55-year-old woman with a history of obesity, hypertension, and prior hemorrhagic stroke presented with recurrent severe hypoglycemia. A diagnostic fast resulted in hypoinsulinemic hypoketotic hypoglycemia. Adrenal function was intact. Progressive myopathy had developed simultaneously with her hypoglycemia, and rheumatologic evaluation revealed mixed connective tissue disease. The plasma acylcarnitine profile was normal, extensive oncologic evaluation including insulin-like growth factor 2 measurement was unrevealing, and anti-insulin antibody testing was negative. Ultimately, anti-insulin receptor antibodies were found to be present. The patient was treated with glucocorticoids and rituximab. Eight weeks after initiation of immunosuppression, the insulin receptor antibody titer had decreased and hypoglycemia had resolved. Eight months after diagnosis, the patient remained free of severe hypoglycemia despite tapering of glucocorticoids to a near-physiologic dose. Though antibodies to the insulin receptor typically cause severe insulin resistance, this patient had no evidence of insulin resistance and instead presented with recurrent severe hypoglycemia, which responded to glucocorticoids and rituximab. The diagnosis of insulin receptor antibody-mediated hypoglycemia is rare but should be considered in patients with systemic autoimmune disease, including mixed connective tissue disease, in the appropriate clinical context.

INSULIN AUTOIMMUNE SYNDROME IN A YOUNG CAUCASIAN WOMAN.

A young Caucasian woman presents several episodes of severe fasting hypoglycemia. Fasting lab tests revealed: glycemia 28 mg/dL, insulinemia 143.3 µU/mL, insulin antibodies above 100 U/mL, leading to the diagnosis of insulin autoimmune syndrome. Due to lack of clinical improvement after 2 months, prednisone was started at 0.5 mg/kg/day, and then tapered by 5 mg every 5 days. Three weeks after discontinuing corticotherapy, the patient had no more severe fasting hypoglycemia, but occasionally postprandial mild hypoglycemia. Fasting lab tests showed: glycemia 83 mg/dL, insulinemia 58.6 µU/mL. At 5 hours during oral glucose tolerance test glycemia was 33 mg/dL, insulinemia 152.9 µU/mL.

Relationship between anti-insulin antibody production and severe insulin resistance in a diabetic cat.

A 5-year-old castrated male domestic shorthair cat was diagnosed with diabetic ketoacidosis and severe insulin resistance. Although the conventional treatment for diabetic ketoacidosis was provided, the cat required frequent hospitalization because of severe dehydration and repeated diabetic ketoacidosis. We detected anti-insulin antibodies for human in this cat. Serum insulin-binding IgG levels were markedly elevated compared with those in healthy cats and other diabetic cats. We initiated prednisolone to suppress the effects of anti-insulin antibodies. After initiation of prednisolone, the cat was gradually recovered with increasing activity and appetite. Furthermore, satisfactory glycemic control was achieved with combined subcutaneous injection of insulin detemir and insulin degludec.