Combined Etanercept, GAD-alum and vitamin D treatment: an open pilot trial to preserve beta cell function in recent onset type 1 diabetes

Interferons are key cytokines acting on pancreatic islets in type 1 diabetes

AIMS/HYPOTHESIS

The proinflammatory cytokines IFN-α, IFN-γ, IL-1β and TNF-α may contribute to innate and adaptive immune responses during insulitis in type 1 diabetes and therefore represent attractive therapeutic targets to protect beta cells. However, the specific role of each of these cytokines individually on pancreatic beta cells remains unknown.

METHODS

We used deep RNA-seq analysis, followed by extensive confirmation experiments based on reverse transcription-quantitative PCR (RT-qPCR), western blot, histology and use of siRNAs, to characterise the response of human pancreatic beta cells to each cytokine individually and compared the signatures obtained with those present in islets of individuals affected by type 1 diabetes.

RESULTS

IFN-α and IFN-γ had a greater impact on the beta cell transcriptome when compared with IL-1β and TNF-α. The IFN-induced gene signatures have a strong correlation with those observed in beta cells from individuals with type 1 diabetes, and the level of expression of specific IFN-stimulated genes is positively correlated with proteins present in islets of these individuals, regulating beta cell responses to 'danger signals' such as viral infections. Zinc finger NFX1-type containing 1 (ZNFX1), a double-stranded RNA sensor, was identified as highly induced by IFNs and shown to play a key role in the antiviral response in beta cells.

CONCLUSIONS/INTERPRETATION

These data suggest that IFN-α and IFN-γ are key cytokines at the islet level in human type 1 diabetes, contributing to the triggering and amplification of autoimmunity.

Verapamil improves One-Year C-Peptide Levels in Recent Onset Type-1 Diabetes: A Meta-Analysis

Meta-analysis studying the role of verapamil in improving C-peptide in people with recent-onset type-1 diabetes (T1DM) has not been conducted to date. We undertook this meta-analysis to address this knowledge gap. Electronic databases were systematically reviewed for RCTs having individuals with T1DM receiving verapamil in the treatment arm and placebo in the control arm over the standard of care. The primary outcome was to evaluate changes in the C-peptide area under the curve (AUC) at a one-year follow-up. Secondary outcomes were to assess alterations in C-peptide AUC, glycated hemoglobin (HbA1c), blood pressure, heart rate, and side effects at different time intervals over a one-year follow-up. From the initially screened 27 articles, data from two RCTs (112 patients) satisfied the inclusion criteria and were analyzed. Compared to placebo, C-peptide AUC in individuals receiving verapamil was not different at three months [MD 0.17 nmol/L (95%CI: -0.05-0.38); P = 0.13; I2 = 86%] but significantly higher at 1-year [MD 0.27 nmol/L (95%CI: 0.19-0.35); P < 0.01; I2 = 12%]. The verapamil arm showed similar changes in HbA1C at three months [MD 0.23% (95%CI: -0.43-0.90); P = 0.49; I2 = 88%] and 1-year [MD 0.18% (95% CI: -0.74 - 1.10); P = 0.70; I2 = 89%] compared to placebo. Occurrence of treatment-emergent adverse events [Risk ratio (RR) 1.90 (95%CI: 0.52-6.91); P = 0.33; I2 = 63%], serious adverse events [RR 1.40 (95%CI: 0.50-3.93); P = 0.53], constipation [RR4.11 (95%CI: 0.93-18.13); P = 0.06; I2 = 0%], headache [RR0.48 (95%CI: 0.16-1.43); P = 0.19; I2 = 0%], severe hypoglycemia [RR 0.87 (95%CI: 0.06 - 13.51); P = 0.92] were comparable across groups. Verapamil was well tolerated, and its use over one year was associated with significant improvements in C-peptide AUC though the HbA1c remained unchanged.

Vitamin D and Beta Cells in Type 1 Diabetes: A Systematic Review

The prevalence of type 1 diabetes (T1D) is rising steadily. A potential contributor to the rise is vitamin D. In this systematic review, we examined the literature around vitamin D and T1D. We identified 22 papers examining the role of vitamin D in cultured β-cell lines, islets, or perfused pancreas, and 28 papers examining vitamin D in humans or human islets. The literature reports strong associations between T1D and low circulating vitamin D. There is also high-level (systematic reviews, meta-analyses) evidence that adequate vitamin D status in early life reduces T1D risk. Several animal studies, particularly in NOD mice, show harm from D-deficiency and benefit in most studies from vitamin D treatment/supplementation. Short-term streptozotocin studies show a β-cell survival effect with supplementation. Human studies report associations between VDR polymorphisms and T1D risk and β-cell function, as assessed by C-peptide. In view of those outcomes, the variable results in human trials are generally disappointing. Most studies using 1,25D, the active form of vitamin D were ineffective. Similarly, studies using other forms of vitamin D were predominantly ineffective. However, it is interesting to note that all but one of the studies testing 25D reported benefit. Together, this suggests that maintenance of optimal circulating 25D levels may reduce the risk of T1D and that it may have potential for benefits in delaying the development of absolute or near-absolute C-peptide deficiency. Given the near-complete loss of β-cells by the time of clinical diagnosis, vitamin D is much less likely to be useful after disease-onset. However, given the very low toxicity of 25D, and the known benefits of preservation of C-peptide positivity for long-term complications risk, we recommend considering daily cholecalciferol supplementation in people with T1D and people at high risk of T1D, especially if they have vitamin D insufficiency.

Glutamic acid decarboxylase immunotherapy for type 1 diabetes

PURPOSE OF REVIEW

To describe recent development of an autoantigen (GAD) treatment towards well tolerated and efficacious precision medicine in type 1 diabetes.

RECENT FINDINGS

Although subcutaneous GAD-alum treatment failed to reach primary endpoint in a phase III trial, metanalyses showed a 97% probability of efficacy, and clear efficacy in patients carrying Hyman Leucoycte Antigen (HLA) DR3DQ2. Efforts have been made to improve efficacy by trying combination therapies with vitamin D + Ibuprofen resp vitamin D + Etanercept (TNF-α inhibition), without any breakthrough until the administration of GAD-alum was changed from subcutaneous to intralymphatic. With a very small dose of GAD-alum (4 μg) given into an inguinal lymph three times with 1 month interval, the efficacy in patients with HLADR3DQ2 has been impressive, with significantly better beta cell preservation than patients who got placebo in a double-blind randomized trial, and clinical efficacy with more patients in partial remission (IDAA1c < 9) and larger proportion of patients with CGM-measured blood glucose Time In Range (TIR), significantly correlated to the C-peptide values. The treatment has been easy for patients and healthcare without treatment-related risk or adverse events.

SUMMARY

Intralymphatic GAD-alum treatment in type 1 diabetes patients carrying HLA DR3DQ2 seems to be an attractive immune intervention.

Immune response differs between intralymphatic or subcutaneous administration of GAD-alum in individuals with recent onset type 1 diabetes

AIMS

Immunomodulation with autoantigens potentially constitutes a specific and safe treatment for type 1 diabetes (T1D). Studies with GAD-alum administrated subcutaneously have shown to be safe, but its efficacy has been inconclusive. Administration of GAD-alum into the lymph nodes, aimed to optimise antigen presentation, has shown promising results in an open-label clinical trial. Herein, we compared the immune response of the individuals included in the trial with a group who received GAD-alum subcutaneously in a previous study.

MATERIALS AND METHODS

Samples from T1D individuals collected 15 months after administration of either three doses 1 month apart of 4 μg GAD-alum into lymph nodes (LN, n = 12) or two doses 1 month apart of 20 μg subcutaneously (SC, n = 12) were studied. GADA, GADA subclasses, GAD₆₅ -induced cytokines, peripheral blood mononuclear cell proliferation, and T cells markers were analysed.

RESULTS

Low doses of GAD-alum into the lymph nodes induced higher GADA levels than higher doses administrated subcutaneously. Immune response in the LN group was characterised by changes in GADA subclasses, with a relative reduction of IgG1 and enhanced IgG2, IgG3, and IgG4 proportion, higher GAD₆₅ -induced secretion of IL-5, IL-10, and TNF-α, and reduction of cell proliferation and CD8⁺ T cells. These changes were not observed after subcutaneous (SC) injections of GAD-alum.

CONCLUSIONS

GAD-specific immune responses 15 months after lymph node injections of GAD-alum differed from the ones induced by SC administration of the same autoantigen.

Viruses and Type 1 Diabetes: From Enteroviruses to the Virome

For over a century, viruses have left a long trail of evidence implicating them as frequent suspects in the development of type 1 diabetes. Through vigorous interrogation of viral infections in individuals with islet autoimmunity and type 1 diabetes using serological and molecular virus detection methods, as well as mechanistic studies of virus-infected human pancreatic β-cells, the prime suspects have been narrowed down to predominantly human enteroviruses. Here, we provide a comprehensive overview of evidence supporting the hypothesised role of enteroviruses in the development of islet autoimmunity and type 1 diabetes. We also discuss concerns over the historical focus and investigation bias toward enteroviruses and summarise current unbiased efforts aimed at characterising the complete population of viruses (the “virome”) contributing early in life to the development of islet autoimmunity and type 1 diabetes. Finally, we review the range of vaccine and antiviral drug candidates currently being evaluated in clinical trials for the prevention and potential treatment of type 1 diabetes.