Long-term Effect of Islet Transplantation on Glycemic Variability

Could Transplantation into the Thyroid Gland Benefit Pancreatic Islet Grafting in Unstable Type 1 Diabetes (T1DM), Complicated Type 2 Diabetes (T2DM), and Patients with Total Pancreatectomy?

BACKGROUND

Insular allograft for unstable type 1 diabetes and autograft in pancreatectomy patients are nowadays considered established procedures with precise indications and predictable outcomes. The clinical outcome of islet transplantation is similar to that of pancreas transplantation, avoiding the complications associated with organ transplantation.

OBJECTIVE

We hypothesised that transplantation of islets of Langerhans within an endocrine organ could better promote their engraftment and function. This could help to resolve or ameliorate known pathological conditions such as unstable type 1 diabetes and complicated type 2 diabetes.

RATIONALE

Pancreatic islet transplantation is currently performed almost exclusively in the liver. The liver provides a sufficiently favourable environment, although not entirely. The hepatic parenchyma has a lower oxygen tension than the pancreatic parenchyma and the vascular structure of the liver is not typical of an exclusively endocrine organ. Moreover, islet transplantation into the liver is not without complications, including hematoma or portal vein thrombosis.

PROPOSED PROJECT

The thyroid gland is the endocrine gland proposed as a 'container'. In fact, it has all the characteristics of 'physio-compatibility' which can address the objectives assumed. It is indeed an ideal site because it is an easily accessible anatomical site that allows islets to be implanted using ultrasound-guided transcutaneous inoculation technique. Moreover, it has physiological and anatomical endocrine affinities with pancreatic islets and, if necessary, it can be removed, using hormone supplementation or replacement therapy.

CONCLUSIONS

The thyroid gland may be proposed as an ideal site for islet implantation due to its anatomical and physiocompatibility characteristics.

Long-term cultures of human pancreatic islets in self-assembling peptides hydrogels

Human pancreatic islets transplantation is an experimental therapeutic treatment for Type I Diabetes. Limited islets lifespan in culture remains the main drawback, due to the absence of native extracellular matrix as mechanical support after their enzymatic and mechanical isolation procedure. Extending the limited islets lifespan by creating a long-term in vitro culture remains a challenge. In this study, three biomimetic self-assembling peptides were proposed as potential candidates to recreate in vitro a pancreatic extracellular matrix, with the aim to mechanically and biologically support human pancreatic islets, by creating a three-dimensional culture system. The embedded human islets were analyzed for morphology and functionality in long-term cultures (14-and 28-days), by evaluating β-cells content, endocrine component, and extracellular matrix constituents. The three-dimensional support provided by HYDROSAP scaffold, and cultured into MIAMI medium, displayed a preserved islets functionality, a maintained rounded islets morphology and an invariable islets diameter up to 4 weeks, with results analogues to freshly-isolated islets. In vivo efficacy studies of the in vitro 3D cell culture system are ongoing; however, preliminary data suggest that human pancreatic islets pre-cultured for 2 weeks in HYDROSAP hydrogels and transplanted under subrenal capsule may restore normoglycemia in diabetic mice. Therefore, engineered self-assembling peptide scaffolds may provide a useful platform for long-term maintenance and preservation of functional human pancreatic islets in vitro.

HLA-B Matching Prolongs Allograft Survival in Islet Cell Transplantation

Islet cell transplantation (ITx) is an effective therapeutic approach for selected patients with type 1 diabetes with hypoglycemia unawareness and severe hypoglycemia events. In organ transplantation, human leukocyte antigen (HLA) mismatching between donor and recipient negatively impacts transplant outcomes. We aimed to determine whether HLA matching has an impact on islet allograft survival. Forty-eight patients were followed up after islet transplantation at our institution from 2000 to 2020 in a retrospective cohort. Patients underwent intrahepatic ITx or laparoscopic omental approach. Immunosuppression was dependent upon the protocol. We analyzed HLA data restricted to A, B, and DR loci on allograft survival using survival and subsequent multivariable analyses. Patients were aged 42.8 ± 8.4 years, and 64.3% were female. Diabetes duration was 28.6 ± 11.6 years. Patients matching all three HLA loci presented longer graft survival (P = 0.030). Patients with ≥1 HLA-B matching had longer graft survival compared with zero matching (P = 0.025). The number of HLA-B matching was positively associated with time of graft survival (Spearman's rho = 0.590; P = 0.034). Analyses adjusted for confounders showed that ≥1 matching for HLA-B decreased the risk of allograft failure (P = 0.009). Our data suggest that HLA-B matching between recipients and donors improved islet allograft survival. Matching all three HLA loci (A, B, and DR) was also associated with prolonged islet allograft survival. Prospective studies and a larger sample size are warranted to validate our findings.

Minimed Medtronic 780G optimizes glucose control in patients with type 1 diabetes mellitus

BACKGROUND AND AIMS

The new advanced hybrid closed loop insulin infusion systems have the potential to significantly improve glycaemic control. The aim of this study was to evaluate the effectiveness of the Minimed 780G system in 59 patients with type 1 diabetes.

METHODS AND RESULTS

Glucose control obtained by using the system in automatic mode at 1-2 months of activation, at 2-4 months, at 4-6 months, and beyond 6 month was compared with those obtained with the system in manual mode. A significant improvement in time-in-range and in time-above-range throughout the follow-up was observed, as well as a significant reduction in time-below-range (<54 mg/dl) after 6 months, a significant reduction of the glucose variability and of HbA1c. After switching the mode, all target percentages lied on the average within the recommended ranges by literature consensus and no severe hypoglycemia nor ketoacidosis episodes were recorded.

CONCLUSION

The Minimed 780G allowed a rapid and progressive improvement of the overall glucose control.

Analysis of the transcriptome and metabolome of pancreatic spheroids derived from human induced pluripotent stem cells and matured in an organ-on-a-chip

The differentiation of pancreatic cells from hiPSC is one of the emerging strategies to achieve an in vitro pancreas model. Here, hiPSC-derived β-like-cells spheroids were cultured in microfluidic environment and characterized using omics analysis.

Perspectives of glycemic variability in diabetic neuropathy: a comprehensive review

Diabetic neuropathy is one of the most prevalent chronic complications of diabetes, and up to half of diabetic patients will develop diabetic neuropathy during their disease course. Notably, emerging evidence suggests that glycemic variability is associated with the pathogenesis of diabetic complications and has emerged as a possible independent risk factor for diabetic neuropathy. In this review, we describe the commonly used metrics for evaluating glycemic variability in clinical practice and summarize the role and related mechanisms of glycemic variability in diabetic neuropathy, including cardiovascular autonomic neuropathy, diabetic peripheral neuropathy and cognitive impairment. In addition, we also address the potential pharmacological and non-pharmacological treatment methods for diabetic neuropathy, aiming to provide ideas for the treatment of diabetic neuropathy.

Zhang et al. describe metrics for evaluating glycaemic variability (GV) in clinical practice and summarize the role and related mechanisms of GV in diabetic neuropathy, including cardiovascular autonomic neuropathy, diabetic peripheral neuropathy and cognitive impairment. They aim to stimulate ideas for the treatment of diabetic neuropathy.

HbA1c reduction following flash monitoring commencement is not independently associated with adverse diabetic eye disease outcomes in type 1 diabetes

INTRODUCTION

Intensification of therapy has been associated with early worsening of retinopathy prior to subsequent risk reduction. We sought to assess whether glycated hemoglobin (HbA1c) reduction, following flash monitoring, was associated with early worsening.

RESEARCH DESIGN AND METHODS

An observational study in 541 individuals with type 1 diabetes and paired HbA1c and eye assessment prior to and following flash monitoring commencement.

RESULTS

Change in HbA1c was -4 mmol/mol (IQR -9-1) (-0.4% (-0.8-0.1)) and 25% achieved a fall in HbA1c of ≥10 mmol/mol. The occurrence of the composite end point (panretinal photocoagulation, macular laser or anti-VEGF therapy) was associated with baseline HbA1c >75 mmol/mol (9.0%) (HR 4.0 (95% CI 2.0 to 7.9), p<0.001) but not with fall in HbA1c of ≥10 mmol/mol (0.9%) (HR 1.6 (95% CI 0.8 to 3.2), p=0.203) over a follow-up period of 615 days (527-863). In multivariate analysis, diabetes duration (p=0.035) and prior retinopathy (p<0.001) were most predictive of the composite end point. Baseline HbA1c was the strongest predictor of worsening retinopathy (p=0.002) or new retinopathy (p=0.002) in multivariate analysis whereas change in HbA1c was not independently associated with either (p=0.930 and p=0.830, respectively).

CONCLUSIONS

Progression of eye disease is associated with baseline HbA1c, diabetes duration and previous retinopathy and such individuals should be monitored during intensification of glycemic therapy. Reassuringly, the extent of glucose lowering does not appear to be an independent risk factor for early worsening of eye disease in this context.

Reduced glycemic variability and flexible graft function after islet transplantation: A case report

To date, studies of patients with islet transplantation addressing intermittently scanned continuous glucose monitoring profile and the flexibility of the graft islet function under different doses of insulin administration, both of which reflect the real daily life of patients, are quite limited. Here, we report a case of a 46‐year‐old woman who received islet transplantation after kidney transplantation. The patient was followed up over a period of 2 years after initial islet transplantation. Our results show that intermittently scanned continuous glucose monitoring can be useful for monitoring the reduction of glycemic variability, and suggest the appropriate regulation of insulin secretion from graft islets during mixed‐meal test by using different doses of exogenous insulin administration. Additionally, during the 2‐year observational period, glucagon elevation was detected only at hypoglycemia, whereas the level was within the normal range at normoglycemia or hyperglycemia.

Allogenic Adipose Tissue-Derived Stromal/Stem Cells and Vitamin D Supplementation in Patients With Recent-Onset Type 1 Diabetes Mellitus: A 3-Month Follow-Up Pilot Study

Objective: To evaluate the short term safety and potential therapeutic effect of allogenic adipose tissue-derived stromal/stem cells (ASCs) + cholecalciferol in patients with recent-onset T1D.

Methods: Prospective, phase II, open trial, pilot study in which patients with recent onset T1D received ASCs (1 × 10⁶ cells/kg) and cholecalciferol 2000 UI/day for 3 months (group 1) and were compared to controls with standard insulin therapy (group 2). Adverse events, C-peptide (CP), insulin dose, HbA1c, time in range (TIR), glucose variability (continuous glucose monitoring) and frequency of CD4⁺FoxP3+ T-cells (flow cytometry) were evaluated at baseline (T0) and after 3 months (T3).

Results: 13 patients were included (8: group 1; 5: group 2). Their mean age and disease duration were 26.7 ± 6.1 years and 2.9 ± 1.05 months. Adverse events were transient headache (n = 8), mild local reactions (n = 7), tachycardia (n = 4), abdominal cramps (n = 1), thrombophlebitis (n = 4), mild floaters (n = 2), central retinal vein occlusion (n = 1, complete resolution). At T3, group 1 had lower insulin requirement (0.22 ± 0.17 vs. 0.61±0.26IU/Kg; p = 0.01) and HbA1c (6.47 ± 0.86 vs. 7.48 ± 0.52%; p = 0.03) than group 2. In group 1, 2 patients became insulin free (for 4 and 8 weeks) and all were in honeymoon at T3 (vs. none in group 2; p = 0.01). CP variations did not differ between groups (−4.6 ± 29.1% vs. +2.3 ± 59.65%; p = 0.83).

Conclusions: Allogenic ASCs + cholecalciferol without immunosuppression was associated with stability of CP and unanticipated mild transient adverse events in patients with recent onset T1D.

ClinicalTrials.gov registration: NCT03920397.