Antibody response to insulin in children and adolescents with newly diagnosed Type 1 diabetes

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.

Development of Insulin Detemir/Insulin Aspart Cross-Reacting Antibodies Following Treatment with Insulin Detemir: 104-week Study in Children and Adolescents with Type 1 Diabetes Aged 2-16 Years

BACKGROUND

To study the long-term development (104 weeks) of insulin antibodies during treatment with insulin detemir (IDet) and insulin aspart (IAsp) in children with type 1 diabetes aged 2-16 years.

METHODS

A 52-week, two-arm, randomized trial comparing IDet and neutral protamine Hagedorn insulin, both in combination with IAsp, was followed by a one-arm, 52-week extension trial of the IDet + IAsp arm. The present analysis was conducted in children who completed the randomized trial and entered into the extension trial.

RESULTS

Of the 177 children randomized to IDet treatment, 146 entered the extension trial. IDet-IAsp cross-reacting antibodies peaked within the first 39 weeks of treatment before gradually declining. A similar pattern was seen for IDet-specific and IAsp-specific antibodies. At end of trial (EOT), no correlation was observed between the level of IDet-specific or IAsp-specific antibodies or IDet-IAsp cross-reacting antibodies and either glycated hemoglobin (HbA1c) or basal insulin dose. Mean HbA1c was stable during the treatment period, with a slight increase over time from 8.41% (68.4 mmol/mol) at baseline to 8.74% (72 mmol/mol) at EOT. Mean IDet dose increased from 0.43 U/kg at baseline to 0.66 U/kg at EOT. Mean IAsp dose increased from 0.46 U/kg to 0.51 U/kg at EOT.

CONCLUSION

Although treatment with IDet and IAsp is associated with development of specific and cross-reacting antibodies, no correlation between insulin antibodies and basal insulin dose or HbA1c was found.

FUNDING

Novo Nordisk A/S. ClinicalTrials.gov identifiers: NCT00435019 and NCT00623194.

Insulin Aspart in the Management of Diabetes Mellitus: 15 Years of Clinical Experience

Limiting excessive postprandial glucose excursions is an important component of good overall glycemic control in diabetes mellitus. Pharmacokinetic studies have shown that insulin aspart, which is structurally identical to regular human insulin except for the replacement of a single proline amino acid with an aspartic acid residue, has a more physiologic time-action profile (i.e., reaches a higher peak and reaches that peak sooner) than regular human insulin. As expected with this improved pharmacokinetic profile, insulin aspart demonstrates a greater glucose-lowering effect compared with regular human insulin. Numerous randomized controlled trials and a meta-analysis have also demonstrated improved postprandial control with insulin aspart compared with regular human insulin in patients with type 1 or type 2 diabetes, as well as efficacy and safety in children, pregnant patients, hospitalized patients, and patients using continuous subcutaneous insulin infusion. Studies have demonstrated that step-wise addition of insulin aspart is a viable intensification option for patients with type 2 diabetes failing on basal insulin. Insulin aspart has shown a good safety profile, with no evidence of increased receptor binding, mitogenicity, stimulation of anti-insulin antibodies, or hypoglycemia compared with regular human insulin. In one meta-analysis, there was evidence of a lower rate of nocturnal hypoglycemia compared with regular human insulin and, in a trial that specifically included patients with a history of recurrent hypoglycemia, a significantly lower rate of severe hypoglycemic episodes. The next generation of insulin aspart (faster-acting insulin aspart) is being developed with a view to further improving on these pharmacokinetic/pharmacodynamic properties.

Impact of anti-insulin antibodies on islet transplantation outcome: data from the GRAGIL Network

BACKGROUND

In patients with type 1 diabetes, insulin antibodies (IA), altering the pharmacokinetics of circulating insulin, might be associated with high glucose concentration, prolonged hypoglycemia, and higher insulin requirement. The impact of IA on islet transplantation has never been explored. Our aim was to evaluate islet transplantation results at 1 year according to the presence of IA.

METHODS

Our work is a retrospective, case-control study, comparing IA-negative and IA-positive patients among the cohort of patients with type 1 diabetes transplanted within the Swiss-French GRAGIL network between 2003 and 2010.

RESULTS

Data about IA were available for 17 patients. Before islet transplantation, 10 patients (59%) were screened positive for IA. At 12 months after transplantation, IA-positive patients reached insulin independence less frequently than IA-negative patients (cumulative incidence of insulin independence, 22.2% vs. 71.4%; P=0.02); β score was ≥7 in 43% of IA-negative patients versus 0% in IA-positive patients (P=0.022). When comparing IA-positive patients with IA-negative patients, insulin dose was 0.15 U/kg (0.10-0.18 U/kg) versus 0.01 U/kg (0-0.09 U/kg) (P=0.2); HbA1c was 6.1% (5.8%-6.3%) versus 6.1% (5.9%-6.8%) (P=0.16); basal C-peptide level was 460 ρmol/L (350-510 ρmol/L) versus 265 ρmol/L (177-405 ρmol/L) (P=0.28); occurrence of hypoglycemia was 12.5% versus 16.5% (P=0.9); and homeostatic model assessment insulin resistance was 1.25 (1-2.4) versus 0.7 (0.52-0.92) (P=0.01).

CONCLUSION

After islet transplantation, IA-positive patients achieved insulin independence less frequently, exhibiting lower β score and higher homeostatic model assessment insulin resistance compared with IA-negative patients. However, in both groups, islet transplantation restored good glycemic control and drastically reduced hypoglycemia and insulin requirements.

Development of insulin antibodies and changes in titers over a long-term period in patients with type 2 diabetes

BACKGROUND

Recently, insulin analogs have become widely used for the treatment of diabetes. The aim of this study was to determine differences in the antigenicity of insulin analogs and long-term changes in titers in patients with type 2 diabetes.

METHODS

Insulin antibodies were examined using polyethylene glycol and protein G methods in 381 patients with type 2 diabetes.

RESULTS

Insulin antibodies were detected in 48 of 118 patients (40.7%) who used insulin, and insulin glargine and aspart were more antigenic. Insulin antibodies were unexpectedly found in seven of 263 patients (2.7%) who had never used insulin. Serum insulin concentrations in patients with insulin antibodies were significantly higher than those without them. Two years after the initial evaluation, insulin antibodies were still positive in 92.7% of patients who used insulin; while, they disappeared in all patients who had never used insulin. A patient who stopped insulin injections 6years ago was found to be positive for insulin antibodies at the first evaluation as well as 2years later.

CONCLUSIONS

Insulin glargine and aspart induced insulin antibodies more frequently, and insulin antibodies remained in patients for a long time. Insulin antibodies should be suspected even in patients not currently on insulin therapy.

Safety and tolerability of glucagon-like peptide-1 receptor agonists in the treatment of type 2 diabetes

Conventional pharmacotherapies for type 2 diabetes effectively lower blood glucose levels but are associated with side effects that preclude their optimal use or raise safety concerns. Novel treatments based on the endogenous hormone glucagon-like peptide-1 (GLP-1) may overcome some of these obstacles. The GLP-1 receptor agonists, exenatide and liraglutide, have a lower risk of hypoglycaemia than some conventional agents and can provide significant weight loss. Although they can cause gastrointestinal symptoms, effects are transient and can be reduced by gradual dose escalation. No cardiac safety issues have been reported and animal studies suggest that they may confer cardiovascular benefits. Pancreatitis has occurred among patients receiving GLP-1 receptor agonists, but it is unclear whether this is drug-related or due to the increased risk of pancreatitis in type 2 diabetes. Despite findings in rodents that GLP-1 receptor activation of thyroid C-cells results in calcitonin release and C-cell pathology, such effects have not been seen with long-term exposure in humans. Immunogenicity does not appear to be a safety concern. In summary, currently available data indicate that GLP-1 receptor agonists provide an effective and generally well tolerated therapeutic option for the management of type 2 diabetes.

Etiopathogenesis of insulin autoimmunity

Autoimmunity against pancreatic islet beta cells is strongly associated with proinsulin, insulin, or both. The insulin autoreactivity is particularly pronounced in children with young age at onset of type 1 diabetes. Possible mechanisms for (pro)insulin autoimmunity may involve beta-cell destruction resulting in proinsulin peptide presentation on HLA-DR-DQ Class II molecules in pancreatic draining lymphnodes. Recent data on proinsulin peptide binding to type 1 diabetes-associated HLA-DQ2 and -DQ8 is reviewed and illustrated by molecular modeling. The importance of the cellular immune reaction involving cytotoxic CD8-positive T cells to kill beta cells through Class I MHC is discussed along with speculations of the possible role of B lymphocytes in presenting the proinsulin autoantigen over and over again through insulin-carrying insulin autoantibodies. In contrast to autoantibodies against other islet autoantigens such as GAD65, IA-2, and ZnT8 transporters, it has not been possible yet to standardize the insulin autoantibody test. As islet autoantibodies predict type 1 diabetes, it is imperative to clarify the mechanisms of insulin autoimmunity.

Diversity in diabetes: the role of insulin aspart

Diabetes management is changing not only with novel treatments but also in patient demography. This presents clinical challenges and influences our view of diabetes therapies. Insulin analogues have been developed to overcome some of the limitations of traditional human insulins, with the aim of providing a more physiological pharmacokinetic/pharmacodynamic profile. The rapid-acting insulin analogue insulin aspart has been investigated in many clinical trials over the past 10 years and the aim of this review is to present the insulin aspart clinical trial data from across the spectrum of patients with diabetes. Five studies have looked at insulin aspart use (including continuous subcutaneous insulin infusion) in children and adolescents, where the analogue was as effective and well tolerated as soluble human insulin. One large-scale, randomized, controlled trial in pregnant women with type 1 diabetes observed trends towards a reduction in major hypoglycaemia, fewer preterm deliveries and lower birthweight with insulin aspart compared with soluble human insulin. Two 6-month, randomized, controlled, multicentre, multinational, parallel-group, open-label trials reported significant reductions in haemoglobin A(1c) and major nocturnal hypoglycaemia with insulin aspart compared with soluble human insulins in patients with type 1 diabetes. There are fewer data involving insulin analogue use in hospitals and in elderly patients with diabetes, but some recent studies have investigated insulin aspart in the emergency department, intensive/non-intensive care setting and in a pharmacokinetic/pharmacodynamic study in patients aged ≥ 65 years. In summary, the evidence would suggest that insulin aspart is suitable for use in a variety of patients with diabetes.

Pan-insulin allergy and severe lipoatrophy complicating Type 2 diabetes

BACKGROUND

  Insulin allergy is a rare complication of insulin use. Localized lipoatrophy is also known to occur following subcutaneous injections of insulin.

CASE REPORT

  A 53-year-old non-obese female patient with Type 2 diabetes displayed local allergic-type symptoms to all available insulin preparations. This was complicated by the development of severe lipoatrophy on her abdominal and thigh injection sites and subsequently resulted in suboptimal glycaemic control.

CONCLUSIONS

  Whilst uncommon, insulin allergy and lipoatrophy can cause major problems in diabetic management. Potential pathophysiological mechanisms and a stepwise approach to management are discussed.

Immunogenicity of different brands of human insulin and rapid-acting insulin analogs in insulin-naïve children with type 1 diabetes

AIMS

To determine (i) whether insulin preparations produced by three companies induce the same immune responses in insulin-naïve children with type 1 diabetes (T1DM); (ii) if switching from human insulin to rapid-acting insulin analogs influences this immune response; and (iii) if different insulin brands produce different clinical results during the first 2 yr after T1DM diagnosis.

METHODS

Insulin antibodies (IA) were measured for 140 patients aged 1.4-17.6 yr. Regular human insulin, neutral protamine Hagedorn (NPH) human insulin, and rapid-acting insulin analogs (lispro or aspart) taken by the patients were produced by one of three companies: Bioton, Poland (A), Eli Lilly, USA (B) and NovoNordisk, Denmark (C).

RESULTS

Positive IA levels were found in 112 patients (80.0%) at baseline and in 137 (97.9%) at 6 and at 24 months after T1DM diagnosis. There was no difference in IA levels among patients taking insulin preparations produced by different companies at 6 months (mean ± SD, A 27.8 ± 15.7%; B 25.3 ± 15.4%; C 24.5 ± 14.2; p = 0.54) or at 24 months (A 25.6 ± 17.8%; B29.6 ± 17.0%; C 26.2 ± 17.0%; p = 0.52); HbA(1c) and daily insulin dose did not differ significantly either. After 24 months, IA levels were similar for those who had used human insulin (mean ± SD, 25.7 ± 17.2%) and for those that had added rapid-acting analogs (28.1 ± 17.3%, p = 0.41).

CONCLUSIONS

Three brands of insulin preparations did not differ with respect to immunogenicity. Rapid-acting analogs did not increase IA levels in patients previously treated with human insulin only. Patients using insulin preparations of different brands did not differ with respect to daily insulin dose or HbA(1c) .

Circulating insulin antibodies: influence of continuous subcutaneous or intraperitoneal insulin infusion, and impact on glucose control

The purification of animal insulin preparations and the use of human recombinant insulin have markedly reduced the incidence, but not completely suppressed, the development of anti-insulin antibodies (IAs). Advances in technologies concerning the mode of delivery of insulin, i.e. continuous subcutaneous insulin infusion (CSII), continuous peritoneal insulin infusion (CPII) and more recently inhaled insulin administration, appear to significantly increase circulating levels of immunoglobulin G (IgG) anti-IAs in diabetic patients. However, the increase is usually moderate and mostly transient as compared to previous observations with poorly purified animal insulin preparations. The clinical impact of these circulating anti-IAs remains unclear. Nevertheless, several studies have suggested that antibodies could retard insulin action, leading to a worsening of postprandial hyperglycaemia and/or serve as a carrier, thus leading to unexpected hypoglycaemia. CPII may be associated with more marked and sustained increase in IAs levels, possibly related to the use of an unstable insulin and the formation of immunogenic aggregates of insulin. The possible clinical consequences of these high levels of IAs remain to be evaluated because a low-glucose morning syndrome or severe insulin resistance with ketone bodies production have been reported in some cases. In conclusion, even if CSII and CPII may promote the development of circulating IAs, this increase does not lead to immunological insulin resistance, compared to that previously described with animal non-purified insulin preparations, and seems to have only marginal influence on blood glucose control or complications in most diabetic patients.