Objective To review the general approaches in isolation and purification of pancreatic islets and progress in several aspects. Methods The latest l iterature concerning acquisition of pancreatic islets was reviewed and analyzed interms of the choice of pancreatic islet donors, the digestion and isolation of pancreas, the purification of islet and the assay of outcome. Results The profile of the isolation and purification depends on the selection of reagents and methods of operation in every step and l inkup between every step. Conclusion Pancreatic islet transplantation is the most effective method to treat type 1 diabetes, the problem of inadequate sources of pancreatic islets could be resolved by the optimal process and the establ ishment of standardized operation.
ObjectiveTo evaluate the 3-year follow-up results of allogeneic islets combined with autologous peripheral blood stem cells (PBSC) transplantation in treatment of type 1 diabetes mellitus (T1MD). MethodsThe clinicopathologic data of recipients underwent allogeneic islet cells combined with (or without) PBSC transplantation in the Sichuan Provincial People’s Hospital from January 2017 to December 2019 were retrospectively analyzed. The allogeneic islet cells combined with (or without) PBSC were infused into the liver by percutaneous hepatic portal vein puncture. Then the modified Edmonton immunosuppressive regimen was used after the operation. The recipients were followed-up for 3 years, and the insulin usage, C-peptide, and glycosylated hemoglobin A1c (HbA1c) were analyzed. ResultsThere were 5 recipients of allogeneic islet cell transplantation alone (named as alone group) and 5 recipients of allogeneic islet cell combined with PBSC transplantation (named as combined group). The gender, age, body mass index, preoperative insulin dosage, and HbA1c concentration of the recipients in the two groups were similar. ① The numbers of islets transplanted in the alone group and combined group were (50.60±2.51)×104 islet equivalent quantity (IEQ) and (48.70±4.76)×104 IEQ, respectively, and the number of PBSC transplanted in the combined group was (9.2±2.6)×107. ② In the alone group and combined group, there were 3 cases and 3 cases of insulin withdrawal at the 12th month, as well as 2 cases and 3 cases of insulin withdrawal at the 36th month after operation, respectively. The postoperative insulin dosages of the two groups were decreased as compared with that before operation, and which of the combined group showed a lower trend as compared with the alone group within 12 months after operation. ③ The C-peptide level at the fasting in the alone group peaked at 24th month after operation and began to decline, and which at the fasting and postprandial 2 h peaked at 12th month after operation and began to decline, but that at postprandial 2 h began to increase slightly at 24th month in the combined group, and which showed a higher trend at 12th and 36th month after operation in the combined group as compared with the alone group. ④ Within 36 months after operation, the HbA1c concentrations of the two groups decreased at different times after operation as compared with those before operation, and basically maintained a normal and stable level at 6 months after operation, and the change trend of the two groups was basically similar. ⑤ There were no obvious immune rejection and adverse reactions in the two groups. ConclusionFrom the preliminary results of this study, PBSC has a certain protective effect on islet transplantation, which improves the clinical efficacy of allograft islet transplantation for 3 years, but the long-term efficacy still needs to be observed, and the mechanism still needs to be further explored.
The islet transplantation site can be divided into two categories: orthotopic islet transplantation and ectopic islet transplantation. Orthotopic islet transplantation refers to that the insulin secreted and released from the transplanted islet will be metabolized into the liver through the hepatic portal vein system, which does not change the original insulin metabolic pathway, including the portal vein of the liver, the greater omentum. The insulin secreted by the ectopic islet transplantation changes the original metabolic pathway of insulin. The ideal islet transplantation site generally has the following characteristics: high success rate transplantation, high long-term survival rate of graft, simple operation, less trauma, less complications, low risk, easy to repeat detection and so on. This article provides a review of the current research status of each islet transplantation site, in order to provide reference for future related research.