L. Kessler

Human islet transplantation network for the treatment of Type I diabetes: first data from the Swiss-French GRAGIL consortium (1999–2000)

Aims/hypothesis. Improvements in islet transplantation require clinical series large enough to implement controlled new strategies. The goal of this study was to demonstrate the feasibility of a multicentre network for islet transplantation in Type I (insulin-dependent) diabetic patients. Methods. The five centres (Besançon, Geneva, Grenoble, Lyon, Strasbourg) of the GRAGIL network allow pancreas procurement, recipient recruitment, transplantation procedure and follow-up. Islet isolation is, however, performed in one single laboratory (Geneva). Pancreata were procured in each of the five centres and transported to Geneva with an ischaemia time of less than 8 hours. Islets were isolated using a standard automated method. If the islet number was too low for a graft ( < 6000 Islet-equivalent /kg), islets were cultured up to 12 days until another isolation was possible. Islets were transplanted by percutaneous transhepatic intraportal injection. Immunosuppression consisted of cyclosporine, mycophenolate mofetil, steroids and an anti-interleukin 2 receptor antibody. Results. From March 1999 to June 2000, 56 pancreata procurements were performed with an average yield of 234 500 islet-equivalent, with 32 preparations over 200 000 islet-equivalent. Ten C-peptide negative Type I diabetic patients (5 men and 5 women, median age 44 years, median diabetes duration 29 years) with an established kidney graft ( > 6 months) received 9030 ± 1090 islet-equivalent/kg with a median purity of 63 %. The number of pancreata required for each graft was 1 (n = 5) or 2 (n = 5). At the completion of a 12 month follow-up, we observed 0 % primary nonfunction, 50 % graft survival and 20 % insulin-independence. Conclusions/interpretation. This study demonstrates the interest and the feasibility of a multicentre collaboration in human islet transplantation. [Diabetologia (2001) 44: 859–864]

Influence of VEGF on the viability of encapsulated pancreatic rat islets after transplantation in diabetic mice.

After pancreatic islet transplantation, insufficient blood supply is responsible for the loss of islet viability. The aim of our study was: 1) to determine the influence of vascular endothelial growth factor (VEGF) on the survival of encapsulated rat islets transplanted into healthy and diabetic mice and 2) to evaluate the metabolic efficiency of the VEGF-supplemented grafts. Twenty-four hours after culture, 50 rat islets immobilized into collagen in the presence of VEGF (100 ng/ml) and encapsulated (AN69 membrane, HOSPAL) were grafted in the peritoneal cavity of healthy or streptozotocin-induced diabetic mice (n = 6). Seven, 14, and 28 days after implantation, the encapsulation device and tissue surrounding the device were removed and the following parameters were analyzed: the number and the diameter of buds, the distance between devices and buds, the amount of cellular adhesion on the capsule surface, and the level of insulin secreted by encapsulated islet. For reversal of diabetes, 1000 rat islets encapsulated in the presence of VEGF were implanted in the peritoneal cavity of diabetic mice and fasting glycemia was analyzed. After 7 days of islet implantation in the absence of VEGF, the bud diameter was 16.1 ± 6.9 μm in diabetic mice and 34.4 ± 3.9 μm in healthy mice. However, the number of buds increased by a factor 2.5 in the presence of VEGF in both types of mice. Furthermore, when islets were transplanted in the presence of VEGF, the distance between the device and the buds was significantly decreased in both types of mice (p < 0.001) after 7, 14, and 28 days of islet implantation. Capsule analysis showed a decrease in cellular adhesion when the islets were encapsulated in the presence of VEGF. Insulin secretion of the islets was higher in the presence of VEGF compared with islets alone at all steps of the study. When 1000 rat islets were transplanted in the presence of VEGF, the glycemia level decreased to 6.2 ± 0.8 mmol/L after 3 days and remained stable until at least 28 days. In contrast, in the absence of VEGF, the initial decrease in the glucose level was rapidly followed by a relapse in hyperglycemia. In summary, VEGF increased the viability of engrafted encapsulated islets, increasing the duration of a normalized glycemia in diabetic mice following transplantation. Local adjunction of VEGF may therefore improve the clinical outcome of islet transplantation.

Expectations and strategies regarding islet transplantation: metabolic data from the GRAGIL 2 trial

Background. Whether islet transplantation should be aimed at restoring insulin independence or providing adequate metabolic control is still debated. The GRAGIL2 trial was designed as a phase 1–2 study where primary outcome was the rate of insulin independence, and secondary outcome was the success rate defined by a composite score based upon basal C-peptide, HbA1c, hypoglycemic events, and exogenous insulin needs. Methods. C-peptide negative type 1 brittle diabetic patients experiencing severe hypoglycemia were eligible to receive a maximum of two islet preparations totalizing 10,000 IE/kg or more, with a threshold of 5,000 IE/kg for the first infusion, according to the Edmonton protocol, within the Swiss-French GRAGIL multicentric network. A sequential analysis with a triangular test was performed in every five patients after 6- and 12-month follow-up. Maximal inefficiency was set at 40% and minimal efficiency at 66%. Results. From September 2003 to October 2005, 10 patients were included. Median waiting time was 6.7 months (first injection) and 9 weeks (second injection). All but one patient received 11,089±505 IE/kg: one received a single graft of 5398 IE/kg. At 6 months, insulin independence and composite success rates were 6 of 10 and 6 of 10, respectively. At 12 months, insulin independence was observed in 3 of 10 patients and success in 5 of 10 patients. Conclusion. Based upon our sequential analysis settings, islet transplantation failed to achieve the primary goal, insulin independence, but tended to succeed in reaching the secondary goal, successful metabolic control. Currently it appears to be a successful biological closed-loop glucose control method for brittle diabetes.

Diabetes and the platelet: Toward new therapeutic paradigms for diabetic atherothrombosis

Atherothrombosis--defined as atherosclerotic lesion disruption with superimposed thrombus formation--is a leading cause of death in patients with diabetes mellitus. Platelets play a pivotal role in atherothrombosis and platelets of diabetic patients are hyperreactive. Numerous studies have investigated the usefulness of antiplatelet therapy for primary and secondary prevention of atherothrombotic events in diabetic patients. However, there are limited evidences that aspirin may be effective in the reduction of atherothrombotic complication in this population. Additionally, dual antiplatelet therapy with aspirin and clopidogrel has been suggested to be harmful. In contrast, the role of antiplatelet therapy in secondary prevention after ischemic cardiac events is well established in diabetes. Glycoprotein IIb/IIIa receptor antagonists can reduce mortality in diabetic patients committed to undergo percutaneous coronary intervention (PCI). Upregulation of P2Y(12) signalling occurs in hyperglycemia, and the relevance of platelet P2Y(12) receptor inhibition with prasugrel in reducing adverse events following PCI has been recently suggested. Besides platelet activation, several other mechanisms may be involved in the pathophysiology of diabetic atherothrombosis. Tissue factor (TF)-bearing procoagulant microparticles (MPs) are a heterogeneous population of membrane-coated vesicles released by several cell lines upon activation or apoptosis. There is converging evidence that MPs and MP-associated TF activity are upregulated in patients with diabetes mellitus and can participate actively in promoting atherothrombotic complications. In this context, drugs that may reduce the release of microparticles and/or their thrombogenic capacity has the potential to improve upon current antiplatelet therapy, possibly resulting in lower adverse events rates in diabetic individuals.

Continuous glucose monitoring in cystic fibrosis patients according to the glucose tolerance.

Cystic fibrosis (CF) is associated with a long preclinical state of abnormal glucose tolerance. The aim of this study was (i) to evaluate the profile of glucose tolerance in young adults with CF and (ii) to compare these results with those obtained by a continuous subcutaneous glucose monitoring (CGMS). CF subjects with fasting glycemia inferior to 126 mg/dl were included in the study. An oral glucose tolerance test (OGTT) identified the subjects either with a normal glucose tolerance (NGT), or impaired glucose tolerance (IGT), or diabetes. CGMS (Medtronic) was performed during 3 days to analyze mean glucose level, high glucose excursions, and glucose area under the curve (AUC). Forty-nine patients were included in the study. NGT (n=22), IGT (n=17), and diabetes groups (n=10) were comparable except with regard to age and BMI (p<0.001). HbA1c values in diabetes group were significantly higher (p<0.001) than in NGT and IGT groups. CGMS revealed peaks of glucose values superior to 200 mg/dl at least once after a meal in 8 patients (36%) with NGT, in 9 patients (52%) with IGT, and in all patients with diabetes (p<0.01). Mean CGMS glucose and glucose AUC values increased in patients with diabetes compared to patients with NGT and IGT (p<0.05). Peak of CGMS glucose reached 182+/-60 mg/dl in NGT group despite the normal glucose profile at OGTT. In conclusion, CGMS revealed pathological glucose excursions not only in patients with impaired glucose tolerance at OGTT but also in patients with a normal glycemic profile. CGMS could be a useful tool for the early detection of hyperglycemia in patients with CF.

Quality of life after islet transplantation: data from the GRAGIL 1 and 2 trials.

Background  Rigorous assessment of health‐related quality of life (HRQL) is mandatory to establish the benefits of islet transplantation.

Five-Year Metabolic, Functional, and Safety Results of Patients With Type 1 Diabetes Transplanted With Allogenic Islets Within the Swiss-French GRAGIL Network

OBJECTIVE To describe the 5-year outcomes of islet transplantation within the Swiss-French GRAGIL Network. RESEARCH DESIGN AND METHODS Retrospective analysis of all subjects enrolled in the GRAGIL-1c and GRAGIL-2 islet transplantation trials. Parameters related to metabolic control, graft function, and safety outcomes were studied. RESULTS Forty-four patients received islet transplantation (islet transplantation alone [ITA] 24 patients [54.5%], islet after kidney [IAK] transplantation 20 patients [45.5%]) between September 2003 and April 2010. Recipients received a total islet mass of 9,715.75 ± 3,444.40 IEQ/kg. Thirty-four patients completed a 5-year follow-up, and 10 patients completed a 4-year follow-up. At 1, 4, and 5 years after islet transplantation, respectively, 83%, 67%, and 58% of the ITA recipients and 80%, 70%, and 60% of the IAK transplant recipients reached HbA1c under 7% (53 mmol/mol) and were free of severe hypoglycemia, while none of the ITA recipients and only 10% of the IAK transplant recipients met this composite criterion at the preinfusion stage. Thirty-three of 44 patients (75%) experienced insulin independence during the entire follow-up period, with a median duration of insulin independence of 19.25 months (interquartile range 2–58). Twenty-nine of 44 recipients (66%) exhibited at least one adverse event; 18 of 55 adverse events (33%) were possibly related to immunosuppression; and complications related to the islet infusion (n = 84) occurred in 10 recipients (11.9%). CONCLUSIONS In a large cohort with a 5-year follow-up and in a multicenter network setting, islet transplantation was safe and efficient in restoring good and lasting glycemic control and preventing severe hypoglycemia in patients with type 1 diabetes.

Incidence and risk factors of glucose metabolism disorders in kidney transplant recipients: role of systematic screening by oral glucose tolerance test.

Background. New-onset diabetes after transplantation (NODAT) increases infectious and cardiovascular complications and reduces patient and graft survival. We assessed the incidence and the risk factors for glucose metabolism abnormalities before and after kidney transplantation using an oral glucose tolerance test (OGTT). The purpose of the study was to better identify patients at risk for NODAT to adapt their immunosuppressive treatment and their management after transplantation. Methods. OGTT was performed before transplantation in 243 patients placed on the kidney waiting list between January 1, 2005, and December 31, 2008. Of these 243 patients, 120 received a kidney transplant and also had an OGTT after transplantation. Results. Impaired glucose tolerance (IGT) was identified in 22 of 120 patients (18%) before transplantation. After transplantation, diabetes developed in 31 patients and 16 patients had IGT. According to univariate analyses, risk factors for NODAT were age more than 50 years, body mass index more than 25 kg/m2, pretransplant IGT, autosomal dominant polycystic kidney disease, and acute rejection. According to multivariate analyses, pretransplant IGT (relative risk=2.4), autosomal dominant polycystic kidney disease (relative risk=3), and acute rejection (RR, 2.8) remained significantly associated with NODAT. Patients were stratified by age, primary kidney disease, and pretransplant OGTT. The risk of developing NODAT increased 2.4-, 5-, and 14-fold, depending on the number of risk factors. Conclusion. Pretransplant OGTT, together with age and nephropathy, is a helpful tool for identifying patients at risk for NODAT. For patients with two or three of these risk factors, the adjustment of immunosuppression may be recommended.

Early assessment of glucose abnormalities during continuous glucose monitoring associated with lung function impairment in cystic fibrosis patients

BACKGROUND Cystic fibrosis-related diabetes (CFRD) is correlated with a decline in lung function. Under certain circumstances, oral glucose tolerance test (OGTT) screening, used to diagnose CFRD, fails to reveal early glucose tolerance abnormalities. In this situation, continuous glucose monitoring (CGM) could be a useful tool for evaluating early abnormalities of glucose tolerance in CF patients. We aimed to study the CGM glucose profile in CF patients with normal OGTT screening results and to evaluate lung function and nutritional status according to the CGM glucose profile. METHODS We assessed glycemic control, the CGM glucose profile, nutritional status, lung function antibiotic courses and colonization (P. aeruginosa and S. aureus) in CF patients, aged 10 years and over, with normal screening OGTT results (blood glucose at T120 min < 7.8 mmol/l). Two groups were identified according to the max CGM glucose value: Group 1<11 mmol/l and Group 2 ≥ 11 mmol/l. RESULTS Among the 38 patients with normal OGTT, 12 (31.6%) were in Group 2. Compared to Group 1, Group 2 patients exhibited a significant impairment in lung function: FEV1, 68.2 ± 25.6% vs. 87.3 ± 17%, p = 0.01 and FVC, 86.1% ± 19.4% vs. 99.3% ± 13.4%, p=0.021, as well as a higher rate of colonization by P. aeruginosa: 83.3% vs. 44%, p=0.024. Nevertheless, there were no differences in nutritional status (BMI standard deviation score: p = 0.079; prealbumin: p = 0.364). CONCLUSIONS CGM reveals early abnormalities of glucose tolerance that remain undiagnosed by OGTT screening and are associated with worse lung function and a higher prevalence of P. aeruginosa colonization in patients with CF. CLINICAL TRIAL REGISTRATION NUMBER NCT00476281.

Influence of islet transportation on pancreatic islet allotransplantation in type 1 diabetic patients within the Swiss-French GRAGIL network

Background. The influence of islet transportation on pancreatic islet allotransplantation in type 1 diabetic patients was evaluated within the GRAGIL network. Patients and Methods. From December 2001 to April 2003, 16 human pancreatic islet transplants were performed in 9 type 1 diabetic patients with an established kidney graft (functioning for at least 6 months) in four centers of the GRAGIL network. Islet isolation was performed in a core laboratory in Geneva, and the islet preparations were shipped by ambulance to each center for transplantation. One month after transplantation, the efficiency of the graft was assessed according to islet transportation time (ITT): ITT less than 2 hours (group 1, n=5), and ITT greater than 4.5 hours (group 2, n=4, mediant 5 hours). Results. Primary graft dysfunction was observed in one patient in group 1 after one month. Two patients became insulin independent in groups 1 and 2. All other patients in both groups had a plasma C-peptide level greater than 0.5 ng/ml. The HbA1c level and the exogenous insulin needs decreased in both groups. Conclusions. ITT does not seem to influence the efficiency of pancreatic islet allotransplantation in type 1 diabetic patients. These results emphasize the scope for multicenter networks such as the GRAGIL group.