Benefits of Islet Transplantation as an Alternative to Pancreas Transplantation: Retrospective Study of More Than 10 Ten Years of Experience in a Single Center.

BACKGROUND: Pancreas transplantation (PTx) represents the method of choice in type 1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. In 2005, the Institute for Clinical and Experimental Medicine (IKEM) launched a program to investigate the safety potential of islet transplantation (ITx) in comparison to PTx. AIM: This study aims to compare the results of PTx and ITx regarding severe hypoglycemia elimination, metabolic control, and complication rate. METHODS: We analyzed the results of 30 patients undergoing ITx and 49 patients treated with PTx. All patients were C-peptide-negative and suffered from hypoglycemia unawareness syndrome. Patients in the ITx group received a mean number of 12,349 (6,387-15,331) IEQ/kg/person administered percutaneously into the portal vein under local anesthesia and radiological control. The islet number was reached by 1-3 applications, as needed. In both groups, we evaluated glycated hemoglobin, insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia, and complications. We used the Mann Whitney test, Wilcoxon signed-rank test, and paired t-test for analysis. We also individually assessed the ITx outcomes for each patient according to recently suggested criteria established at the EPITA meeting in Igls. RESULTS: Most of the recipients showed a significant improvement in metabolic control one and two years after ITx, with a significant decrease in HbA1c, significant elevation of fasting and stimulated C-peptide, and a markedly significant reduction in insulin dose and the frequency of severe hypoglycemia. Seventeen percent of ITx recipients were temporarily insulin-independent. The results in the PTx group were comparable to those in the ITx group, with 73% graft survival and insulin independence in year 1, 68% 2 years and 55% 5 years after transplantation. There was a higher rate of complications related to the procedure in the PTx group. Severe hypoglycemia was eliminated in the majority of both ITx and PTx recipients. CONCLUSION: This report proves the successful initiation of pancreatic islet transplantation in a center with a well-established PTx program. ITx has been shown to be the method of choice for hypoglycemia unawareness syndrome, and may be considered for application in clinical practice if conservative options are exhausted.

[Islet transplantation as a treatment for hypoglycemia unawareness syndrome. Evaluation of the pilot program and comparison with pancreas transplantation]. / Transplantace Langerhansových ostruvku v lécbe syndromu poruseného vnímání hypoglykemie. Vyhodnocení pilotního programu a porovnání s transplantací pankreatu.

Islet transplantation (ITx) started in 2005 in IKEM as a potentially safer alternative to pancreas transplantation (PTx), which so far had represented the method of choice in type-1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. The aim of the study was to compare these two methods with regard to severe hypoglycemia elimination and to frequency of complications.Up to November 2015 a total number of 48 patients underwent ITx. The results from 22 patients with hypoglycemia unawareness were statistically analyzed. The mean number of transplanted islet equivalents was 12,096 (6,93316,705) IEQ/kg administered percutaneously in local anesthesia under radiological control to the portal vein. 44 patients underwent PTx from 1996. We evaluated glycated hemoglobin(HbA1c), insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia and complications. Medians (interquartile range) were analyzed using the Wilcoxon signed-rank test.One and two years after ITx, HbA1c decreased, C-peptide became significantly positive, insulin dose and frequency of severe hypoglycemia decreased and 18 % of ITx recipients were temporarily insulin-independent. Bleeding was present in 41 % of patients. One year after PTx, 73 % of patients were insulin and hypoglycemia-free, after two years 68 % of patients were insulin and hypoglycemia-free; graftectomy occurred in 20 % of recipients.Both methods led to restoration of insulin secretion and severe hypoglycemia elimination. PTx made more recipients insulin-independent at the cost of serious complications.

Combining Donor Characteristics with Immunohistological Data Improves the Prediction of Islet Isolation Success.

Variability of pancreatic donors may significantly impact the success of islet isolation. The aim of this study was to evaluate donor factors associated with isolation failure and to investigate whether immunohistology could contribute to organ selection. Donor characteristics were evaluated for both successful (n = 61) and failed (n = 98) islet isolations. Samples of donor pancreatic tissue (n = 78) were taken for immunohistochemical examination. Islet isolations with 250000 islet equivalents were considered successful. We confirmed that BMI of less than 25 kg/m2 (P < 0.001), cold ischemia time more than 8 hours (P < 0.01), hospitalization longer than 96 hours (P < 0.05), higher catecholamine doses (P < 0.05), and edematous pancreases (P < 0.01) all unfavorably affected isolation outcome. Subsequent immunohistochemical examination of donor pancreases confirmed significant differences in insulin-positive areas (P < 0.001). ROC analyses then established that the insulin-positive area in the pancreas could be used to predict the likely success of islet isolation (P < 0.001). At the optimal cutoff point (>1.02%), sensitivity and specificity were 89% and 76%, respectively. To conclude, while the insulin-positive area, determined preislet isolation, as a single variable, is sufficient to predict isolation outcome and helps to improve the success of this procedure, its combination with the established donor scoring system might further improve organ selection.

[Islet transplantation for treatment of type-1 diabetes mellitus]. / Lécba diabetu transplantací izolovaných Langerhansových ostruvku.

BACKGROUND: Organ pancreas transplantation represents the only method enabling long-term normalization of glucose metabolism in type-1 diabetic subjects so far. Unfortunately, surgical complications of this kind of therapy are still frequent. As a safer alternative, transplantation of isolated pancreatic islets was introduced at the Institute for Clinical and Experimental Medicine as a clinical experiment in the year 2005. METHODS AND RESULTS: We isolated the islets from pancreases of cadaveric donors which did not fulfil criteria to perform organ pancreas transplantation. Altogether, 36 islet implantations were performed in 28 C-peptide negative subjects suffering from type-1 diabetes by August 2010. In 15 subjects (21 implantations) the main indication was extremely instable course of diabetes due to the hypoglycaemia unawareness syndrome. In 5 and 3 cases, combined islet and kidney and islet and liver transplants were performed, respectively. In addition, islet autotransplantation was performed in 5 subjects undergoing total pancreatectomy. No patient died during the study period. In all but 1 patient with primary islet afunction, islet transplantation led to a complete cure of the hypoglycemia unawareness syndrome. Out of 15 patients, 11 subjects in this group showed a significant C-peptide production (> 0.2 pmol/ml) after 1 year. The mean insulin dose after allotransplantation decreased from 37 to 14 units per day and in 3 subjects, insulin therapy could be withdrawn. Serious technical complications occurred in 6 subjects, which only in 2 cases required surgical revision and did not cause long-term sequels. CONCLUSIONS: In comparison with organ pancreas transplantation, pancreatic islet transplantation represents a substantially safer method for restitution of endogenous insulin production. Though it eliminates serious hypoglycemic episodes in labile diabetes, complete insulin withdrawal is still often not possible. However, due to continuing progress in the laboratory techniques as well as in the transplant procedure itself, the results are steadily improving.