Current status and future of new technologies in the treatment of type 1 diabetes / 中国医师杂志

Type 1 diabetes mellitus (T1DM) is an organ-specific disease characterized by autoimmune damage to pancreatic β cells. Insulin therapy is the most basic and important treatment for T1DM, but insulin therapy cannot fundamentally terminate or improve the main cause of T1DM, namely the disorder of the immune regulation mechanism. With the advancement of science and technology, the continuous development of new insulin and hypoglycemic drugs has provided better means for glycemic control. Pancreas transplantation, islet transplantation, immunotherapy, and cell therapy have provided hope for the prevention or reversal of T1DM. It is of great significance to understand the current situation and future of new technologies for T1DM treatment for the research and management of T1DM patients.

Research advances in total pancreatectomy with autologous islet cell transplantation / 临床肝胆病杂志

Since the 1970s， patients with chronic pancreatitis （CP） have benefited from total pancreatectomy with autologous islet cell transplantation （TPAIT）. With the continuous development of surgical techniques and perioperative management over the past few decades， there have been improvements in islet cell function， insulin independence rate， and the survival rate of patients. This article summarizes the preoperative indications for TPAIT， the development of surgical operations， postoperative management and monitoring， and prognosis， so as to help clinicians learn more about TPAIT.

The research progress of total pancreatectomy with islet autotransplantation for chronic pancreatitis patients / 中华肝胆外科杂志

Chronic pancreatitis is a progressive chronic inflammatory disease of caused by gene and other environmental factors, and clinical manifestation includes recurrent abdominal pain and dysfunction of exocrine and endocrine. For the chronic pancreatitis therapy, surgical treatment mainly aims at the intractable pain which is unresponsive to medical and endoscopic treatment, as well as complications of chronic pancreatitis. Total pancreatectomy with islet autotransplantation (TPIAT) gradually becomes a major therapeutic option for chronic pancreatitis surgical treatment, because it relieves the abdominal pain, reduces the opioid dependent, improves the quality of life, and increases the opportunity of insulin independent. In the past few years, a range of researches have been focusing on islet isolation, surgical approach, curative effect and postoperative complication, improvement of islet function after operation. The purpose of this article is to summarize the progression of TPIAT related research in the recent years.

Alginate-Catechol Cross-Linking Interferes with Insulin Secretion Capacity in Isolated Murine Islet Cells

Over the past three decades, human pancreatic islet isolation and transplantation techniques have developed as a routine clinical procedure for selected patients with type 1 diabetes mellitus. However, due to the donor shortage and required chronic systemic immunosuppression, the widespread application of islet transplantation is limited. To overcome these limitations, providing a physical barrier to transplanted islet cells with encapsulating biomaterial has emerged as a promising approach to enhance engraftment and promote islet survival post-transplantation. Alginate has been considered to be a reliable biomaterial, as it enhances islet survival and does not hamper hormone secretion. Alginate-catechol (Al-CA) hydrogel was reported to provide high mechanical strength and chemical stability without deformation over a wide range of pH values. In this study, we, demonstrated, for the first time in the literature, that encapsulation of murine pancreatic islet cells with Al-CA hydrogel does not induce cytotoxicity ex vivo for an extended period; however, it does markedly abate glucose-stimulated insulin secretion. Catechol should not be considered as a constituent for alginate gelation for encapsulating islet cells in the application of islet transplantation.

Stepwise Approach to Problematic Hypoglycemia in Korea: Educational, Technological, and Transplant Interventions

Impaired awareness of hypoglycemia has been found to be prevalent in 20% to 40% of people with type 1 diabetes. If a similar prevalence exists in Koreans with type 1 diabetes, at a minimum, thousands of people with type 1 diabetes suffer at least one unpredicted episode of severe hypoglycemia per year in Korea. For patients with problematic hypoglycemia, an evidence-based stepwise approach was suggested in 2015. The first step is structured education regarding multiple daily injections of an insulin analog, and the second step is adding a technological intervention, such as continuous subcutaneous insulin infusion or real-time continuous glucose monitoring. The next step is a sensor-augmented pump, preferably with a low glucose suspension feature or very frequent contact, and the final step is islet or pancreas transplantation. In Korea, however, none of these treatments are reimbursed by the National Health Insurance, and thus have not been widely implemented. The low prevalence of type 1 diabetes means that Korean physicians are relatively unfamiliar with the new technologies in this field. Therefore, the roles of new technologies and pancreas or islet transplantation in the treatment of problematic hypoglycemia need to be defined in the current clinical setting of Korea.

Is islet transplantation a realistic approach to curing diabetes?

Since the report of type 1 diabetes reversal in seven consecutive patients by the Edmonton protocol in 2000, pancreatic islet transplantation has been reappraised based on accumulated clinical evidence. Although initially expected to therapeutically target long-term insulin independence, islet transplantation is now indicated for more specific clinical benefits. With the long-awaited report of the first phase 3 clinical trial in 2016, allogeneic islet transplantation is now transitioning from an experimental to a proven therapy for type 1 diabetes with problematic hypoglycemia. Islet autotransplantation has already been therapeutically proven in chronic pancreatitis with severe abdominal pain refractory to conventional treatments, and it holds promise for preventing diabetes after partial pancreatectomy due to benign pancreatic tumors. Based on current evidence, this review focuses on islet transplantation as a realistic approach to treating diabetes.

Comparative efficacy of Belzer or Euro-Collins solutions for pancreatic preservation during cold ischemic storage in rats

To compare the efficacy of different types of solutions (Belzer or Euro-Collins) for the preservation of rat pancreas during cold ischemia. METHODS: Thirty Wistar rats were divided into three groups according to the perfusion or storage solution: Group E (perfusion and storage in Euro-Collins solution); Group B (perfusion and storage in Belzer solution) and Group BE (Perfusion in Belzer solution and storage in Euro-Collins solution). After perfusion, the pancreas was excised and stored at 4˚C for 18 hours. Amylase was measured at 6, 12 and 18h, and histological analysis of the pancreas was performed after 18h of cold storage. RESULTS: Amylase was elevated and comparable in Groups E and BE after 12 and 18 hours of ischemia (p<0.05). In the exocrine pancreas, histological differences in the amount of necrosis (p=0.049), lymphocytic infiltrate (p<0.001) and neutrophilic infiltrate (p=0.004) were observed, with more favorable features present in Group B. In the endocrine pancreas, Group B showed less edema (p<0.001), but other parameters were similar among all groups. CONCLUSION: The Euro-Collins solution is inferior to the Belzer solution for the preservation of rat pancreas during cold ischemia.

The Influences of Pre-injection of Donor Apoptotic Cells on Survival of Islet Grafts and Function of T Lymphocytes / 天津医药

Objective To study the influence of pre-injection of donor apoptotic cells in the survival of islet grafts and the function of T lymphocytes in the peripheral blood. Methods The donor apoptotic cells and necrotic cells were ob-tained respectively by X-irradiation from electron linear accelerator and a heat-shock procedure (water bath box 56℃, 1 h). The diabetic rats for islet transplantation (n=42) were induced by a single intraperitoneal injection of streptozotocin (STZ), then were randomly divided into four groups:rats were injected by physiological saline group (n=9), normal cells group (n=12), apoptotic donor cell group (n=12) and necrotic donor cell group (n=9). On the seventh day, each group received islet transplantation under the renal capsule. The blood glucose level was detected to reflect the survival of the islets. The periph-eral blood samples of three rats in each group were obtained at different observation times. The proliferative activity of T lym-phocytes was determined by MTT method. The levels of cytokines interferon (IFN)-γ, interleukin (IL)-10 in peripheral blood were measured by Luminex 100 Integrated System, and transforming growth factor (TGF)-β1 by ELISA respectively at 0 d, 1 week, 2 weeks and after rejection. Results The survival time of islets was significantly prolonged by the pre-intervention of apoptotic cells, and the proliferative activity of T lymphocytes stimulated by ConA was inhibited. Meanwhile, the extent of the increased level of IFN-γwas inhibited significantly at 1 week and 2 weeks after transplantation (P<0.05), the levels of IL-10 and TGF-β1 were significantly increased before transplantation, 1 week and 2 weeks after transplantation (P<0.05). Conclusion Our results demonstrated that the pre-treatment of donor apoptotic cells can regulate the recipient’s immune reactive state by inhibiting the proliferative activity of T lymphocytes and changing the levels of cytokines from different sub-sets of T lymphocytes, and finally resulted in the prolonging of the survival of islet grafts.

Co-transplantation of fetal rat pancreatic stem cells and islets of langerhans to preserve viability of islets / 中国组织工程研究

BACKGROUND:Pancreatic stem cels can maintain the islet structurein vitro, reduce necrosis and apoptosis of islet cels,in vitro prolong islet survival, and keep islet activity. OBJECTIVE: To observe the possibility of preserving viability of isletsin vivo by co-transplanting fetal rat pancreatic stem cels and islets so as to improve the outcome of islet transplantation. METHODS:Thirty-five adult rats were randomly divided into five groups, including co-transplantation, islet transplantation alone, pancreatic stem celltransplantation alone, diabetes control and normal control groups. Diabetic models were established in the former four groups by intraperitoneal injection of streptozotocin-citrate buffer. Pancreatic stem cels from the fetal rats at pregnant 16 days or islets from adult Sprague-Dawley rats. RESULTS AND CONCLUSION:In the co-transplantation group, the levels of blood glucose and plasma insulin returned to the normal after 5 days of co-transplantation, and the survival time of islets was (18.2±2.4) days. In the islet transplantation alone group, the level of blood glucose was reduced to normal after 1 week of transplantation, and the survival time of islets was (14.4±2.1) days. Significant different was found between the survival time of islets between this two groups (P < 0.05). However, the level of blood glucose was stil abnormal in the other groups. These findings indicate that the co-transplantation of fetal rat pancreatic stem cels and islets can prolong the survival time of isletsin vivo, protect viability of islets and improve the outcome of islet transplantation.

Mice islet allograft tolerance induced by blockade of OX40/OX40L and CD40/CD154 costimulation pathway / 中华器官移植杂志

Objective To investigate the effects of blockade of OX40/OX40L costimulation pathway on mice islet allograft tolerance in CD40/CD154 costimulation pathway blockade mice.Methods C57BL/6 mice were induced into diabetes mellitus as recipients,and were transplanted with DBA/2 mice islets.The recipients were divided into four groups,(1) treated with IgG as controls,(2) anti-OX40L mAb,(3) anti-CD154,(4) combined treatment of anti-OX40L mAb and anti CD154mAb.The mean survival time (MST) of islet allograft was observed.The expression of OX40 in activated T cells of CD154 deficient mice was detected.Effector T cells were obtained from the spleen of CD154 deficient mice cultured with or without anti-OX40L mAb for 3 days.The proliferation of T cells was assayed.Results The MST in the control group,anti-OX40L mAb group,anti-CD154 mAb group and anti OX40L mAb + anti-CD154 mAb group was 19,22,48,and ＞150 days respectively (P ＜0.05).The OX40 expression was readily induced in the 66％ activated T effector cells.CD154 deficient T effector cells proliferation was inhibited by the addition of anti-OX40L mAb in the culture in a dose-dependent fashion.Conclusion The blockade of OX40/OX40L costimulation pathway can promote islet allograft tolerance in CD40/CD154 costimulation pathway blockade mice by inhibiting the proliferation of T cells.

Functional improvement of porcine neonatal pancreatic cell clusters via conformal encapsulation using an air-driven encapsulator

Transplantation of islet cells into diabetic patients is a promising therapy, provided that the islet cells are able to evade host immune rejection. With improved islet viability, this strategy may effectively reverse diabetes. We applied 2% calcium alginate to generate small and large capsules to encapsulate porcine neonatal pancreatic cell clusters (NPCCs) using an air-driven encapsulator. After encapsulation, the viability was assessed at 1, 4, 7, 14 and 28 days and secretion of functional insulin in response to glucose stimulation were tested at days 14 and 28. Selective permeability of the small alginate capsules was confirmed using various sizes of isothiocyanate-labeled dextran (FITC-dextran). Encapsulation of NPCCs was performed without islet protrusion in the small and large capsules. The viability of NPCCs in all experimental groups was greater than 90% at day 1 and then gradually decreased after day 7. The NPCCs encapsulated in large capsules showed significantly lower viability (79.50 +/- 2.88%) than that of naive NPCCs and NPCCs in small capsule (86.83 +/- 2.32%, 87.67 +/- 2.07%, respectively) at day 7. The viability of naive NPCCs decreased rapidly at day 14 (75.67 +/- 1.75%), whereas the NPCCs encapsulated in small capsules maintained (82.0 +/- 2.19%). After 14 and 28 days NPCCs' function in small capsules (2.67 +/- 0.09 and 2.13 +/- 0.09) was conserved better compared to that of naive NPCCs (2.04 +/- 0.25 and 1.53 +/- 0.32, respectively) and NPCCs in large capsules (2.04 +/- 0.34 and 1.13 +/- 0.10, respectively), as assessed by a stimulation index. The small capsules also demonstrated selective permeability. With this encapsulation technique, small capsules improved the viability and insulin secretion of NPCCs without islet protrusion.

Islet transplantation in rodents. Do encapsulated islets really work? / Transplante de ilhotas de Langerhans em modelos experimentais em roedores. Ilhotas encapsuladas realmente funcionam?

CONTEXT: Diabetes mellitus type I affects around 240 million people in the world and only in the USA 7.8 percent of the population. It has been estimated that the costs of its complications account for 5 percent to 10 percent of the total healthcare spending around the world. According to World Health Organization, 300 million people are expected to develop diabetes mellitus by the year 2025. The pancreatic islet transplantation is expected to be less invasive than a pancreas transplant, which is currently the most commonly used approach. OBJECTIVES: To compare the encapsulated and free islet transplantation in rodents looking at sites of islet implantation, number of injected islets, viability and immunosuppression. METHODS: A literature search was conducted using MEDLINE/PUBMED and SCIELO with terms about islet transplantation in the rodent from 2000 to 2010. We found 2,636 articles but only 56 articles from 2000 to 2010 were selected. RESULTS: In these 56 articles used, 34 percent were encapsulated and 66 percent were nonencapsulated islets. Analyzing both types of islets transplantation, the majority of the encapsulated islets were implanted into the peritoneal cavity and the nonencapsulated islets into the liver, through the portal vein. In addition, the great advantage of the peritoneal cavity as the site of islet transplantation is its blood supply. Both vascular endothelial cells and vascular endothelial growth factor were used to stimulate angiogenesis of the islet grafts, increasing the vascularization rapidly after implantation. It also has been proven that there is influence of the capsules, since the larger the capsule more chances there are of central necrosis. In some articles, the use of immunosuppression demonstrated to increase the life expectancy of the graft. CONCLUSION: While significant progress has been made in the islets transplantation field, many obstacles remain to be overcome. Microencapsulation provides a means to transplant islets without immunosuppressive agents and may enable the performance of xenotransplantation. The use of alternative donor sources, fewer islets per capsule and the appropriate deployment location, such as the peritoneal cavity, may give a future perspective to the application of immunoprotective capsules and viability in clinical practice. A variety of strategies, such as genetic engineering, co-encapsulation, improvement in oxygen supply or the establishment of hypoxia resistance will also improve the islet transplantation performance. It remains to be determined which combination of strategies with encapsulation can fulfill the promise of establishing a simple and safe transplantation as a cure for diabetes.

CONTEXTO: Diabetes mellitus tipo I afeta cerca de 240 milhões de pessoas no mundo e 7,8 por cento só nos EUA. Foi estimado que o custo de suas complicações fosse de 5 por cento-10 por cento dos custos mundiais em saúde. De acordo com a OMS (Organização Mundial de Saúde), espera-se que cerca de 300 milhões de pessoas desenvolvam o diabetes mellitus até o ano de 2025. É esperado que o transplante de ilhotas pancreáticas seja menos invasivo que o transplante pancreático, opção atual de maior uso. OBJETIVOS: Comparar as ilhotas encapsuladas e as ilhotas livres em roedores nos seguintes aspectos: local de implantação das ilhotas, número de ilhotas, viabilidade e imunossupressão. MÉTODOS: A pesquisa bibliográfica foi conduzida com o uso de citações do MEDLINE/PUBMED e SCIELO que apresentassem termos sobre transplante de ilhotas em roedores no período de 2000 a 2010. Foram achados 2.636 artigos, mas somente 56 desse período foram selecionados. RESULTADOS: Nos 56 artigos utilizados, 34 por cento eram encapsulados e 66 por cento eram não-encapsulados. Analisando ambos os tipos de transplante de ilhotas, a maioria delas encapsuladas, foi implantada na cavidade peritonial e as não-encapsuladas, através da veia porta, no fígado. A grande vantagem da cavidade peritonial como local de transplante era a oferta sanguínea. As células endoteliais e o fator de crescimento endotelial foram usados para estimular a angiogênese nas ilhotas, aumentando a vascularização rapidamente após a implantação. Foi também provada a influência das cápsulas, dado que quanto maior a cápsula maior era a chance de necrose central. Em alguns artigos, o uso de imunossupressão demonstrou aumento da expectativa de vida do enxerto. CONCLUSÃO: Enquanto algum progresso significativo não tenha sido obtido no campo de transplante de ilhotas, restam ainda muitos obstáculos a serem vencidos. A microencapsulação viabiliza o transplante de ilhotas sem o uso de imunossupressores, o que pode permitir o xenotransplante. O uso de fontes doadoras alternativas, menor quantidade de ilhotas por cápsula e local de implantação adequado, como a cavidade peritonial, podem dar melhor perspectiva na aplicação de cápsulas imunoprotegidas, aumentando viabilidade na prática clínica. Uma série de estratégias, como engenharia genética, coencapsulamento, melhora da oferta de oxigênio ou o estabelecimento de resistência à hipóxia também podem aprimorar os resultados do transplante de ilhotas. Deve-se determinar ainda qual a combinação de estratégias com relação ao uso de ilhotas encapsuladas que possam cumprir com as promessas de um transplante simples e seguro para a cura do diabetes.

Role of OX40 in mechanisms of memory T cells in islet transplant tolerance / 中华器官移植杂志

Objective To investigate the role of OX40 in the mechanisms of memory T cells in islet transplant tolerance.Methods The expression of OX40 on native, like memory and memory CD8+T cells was detected by RT-PCR. Splenic T cells from B6 mice were injected into Rag-/- mice via the tail vein, and the Rag-/- mice were divided into three groups (n=8 each): control group, given IgG; treatment group, given anti-OX40L; and OX40 knock-out group, given T cells from OX40 knock-out B6 mice spleen. All recipients were induced into diabetes mellitus model after adoptive transfer. Islet transplantation was performed on all Rag-/- mice as recipients. The mean survival time of islet was observed.Results The expression of OX40 in native T cells, like memory T cells and memory T cells was 2.87, 111.24 and 146.15 respectively. The expression of OX40 in like memory and memory T cells was higher than in native T cells (P<0.05). Comparison with control group , The mean survival time of the DBA/2 islet allografts in treatment group (130 days) and OX40 knock-out group (125 days) was significantly longer than in control group (21 days, P<0.05).Conclusion The OX40 expression is high in memory T cells. The mean survival time of the islet allografts can be prolonged by blocking OX40/OX40L pathway. OX40/OX40L pathway may be the key point of transplant tolerance.

Bone marrow-derived mesenchymal stem cells protect allogenic islets / 中华普通外科杂志

Objective To study the protection of mouse bone marrow-derived mesenchymal stem cells ( MSCs) for allogenic islets. Method MSCs from C57BL/6 mice were preceded to a 24-well culture plate with the density of 3 × 104/well. On the second day, islets were isolated, purified and divided to undergo streptozotocin (STZ) induced chemical injury and mixed lymphocyte reaction ( MLR) respectively. Then, treated and control islets were respectively divided into the following groups: islets + MSCs, STZ-islets + MSCs, and MLR-islets + MSCs. As control groups for their counterparts, treated or non-treated islets were also cultured without MSCs. On the 5th day incubation, glucose-stimulated insulin secretion test was performed to assess the function of islets in different groups, comparing their insulin-secretion amount stimulated by low or high glucose and the stimulation index determined by the ratio of (insulin amount secreted under high-glucose stimulation)/(insulin amount secreted under low-glucose stimulation ). Islet viability was evaluated by acridine orange (AO)/propidium iodide (PI) fluorescence staining. Result As shown by AO/PI staining, large numbers of dead cell with red fluorescence could be observed in STZ- or MLR- treated islets without MSCs, while the number of dead cells obviously reduced in MSC-cocultured islets with increased viable cells of green fluorescence. STZ- or MLR- treated islets exhibited apparently decreased insulin-secretion amount either under low- or high-glucose stimulation, as well as the stimulation index. The insulin-secretion function was significantly improved in islets cocultured with allogenic MSCs (P ＜ 0. 05 ). Conclusions Bone marrow-derived MSCs can protect isolated allogenic islets against chemical and immunological injury.

CD103 molecule-mediated pancreatic islet allograft injury induced by CD8 T cells / 中华器官移植杂志

Objective To test whether the CD103 molecule mediates CD8+ T lymphocytes on allogeneic islet graft immune injury. Methods By using flow cytometry, the expression of CD103 in peripheral CD8+ T lymphocytes in wild-type C57BL/6 mice was detected. Allogenic islet transplantation models were made using Balb/c donor mice and C57BL/6 recipient mice. Recipients were divided into 3 groups: M290-SAP-treated mice were injected with CD103 immunotoxin M290-SAP; M290-treated mice were injected with CD103 monoclonal antibody M290; untreated mice were only transplanted islet without any drug treatment. CD3, CD8, CD44 and CD103 positive cells were counted in islet allograft infiltrative lymphocytes. CD3, CD8, and CD103 positive cells were measured in the mesenteric lymph node. The islet allografts were removed and subjected to HE staining and immunohistochemical staining at the time of graft loss or the end of the observation period. Results 44. 06% peripheral CD8+ T cells expressed CD103 in wild-type C57BL/6 mice. 29 % CD8+ T cells expressed CD103 in the infiltrative lyrnphocytes of islet allografts in the untreated mice. In M290-SAP-treated mice, the lymphocytes had no CD103 expression and the absolute number of CD8+ lymphocytes was decreased as well The blood glucose was maintained stable for more than 100 days (13 days in untreated group, P＜0.05) in the M290-SAP-treated mice. Moreover, the transplanted islets retained intact. Conclusion CD103 expression is required for destruction of pancreatic islet allograft by CD8+ T cells. CD103 might provide a novel target for therapeutic intervention in islet allograft rejection.

Infusion of donor-specific regulatory T cells prolonged islet allograft survival in mice / 中华器官移植杂志

Objective To investigate the effects of donor-specific regulatory T cells (Treg) transfusion on islet allograft survival. Methods Allogeneic fresh islets from Balb/c mice were transplanted to streptozotocin-induced diabetic C57 mice. The survival of islet allografts was observed. The experiment was divided into 3 groups: control group, nothing had been done to the recipients; simple islet transplantation group, the recipients received the islet transplantation only; experimental group, the recipients were given 1 ×106 Treg, then received islet transplantation. Results Blood glucose (BG) was above 16. 7 mmol/L after islet transplantation in control group; In simple islet transplantation group,BG level returned to normal level 1 to 2 days after transplantation, and hyperglycemia appeared 7 to 11 days after transplantation and maintained as the same as that before transplantation; In experimental group, BG level returned to normal level 2 days after transplantation and maintained at a low level,and at the 21st day after transplantation BG level was over 16. 7mmol/L in some recipients. Islet allograft survival in experimental group was significantly prolonged as compared with simple islet transplantation group. Conclusion Donor-specific Treg transfusion could prolong the islet allograft survival,and maybe have positive effect on tolerance induction of islet transplantation.

Pancreatic islet allograft in spleen with immunossuppression with cyclosporine. Experimental model in dogs / Alotransplante de ilhotas pancreáticas no baço com imunossupressão com ciclosporina. Modelo experimental em cães

PURPOSE: To study the functional behavior of the allograft with immunosuppression of pancreatic islets in the spleen. METHODS: Five groups of 10 Mongrel dogs were used: Group A (control) underwent biochemical tests; Group B underwent total pancreatectomy; Group C underwent total pancreatectomy and pancreatic islet autotransplant in the spleen; Group D underwent pancreatic islet allograft in the spleen without immunosuppressive therapy; Group E underwent pancreatic islet allograft in the spleen and immunosuppression with cyclosporine. All of the animals with grafts received pancreatic islets prepared by the mechanical-enzymatic method - stationary collagenase digestion and purification with dextran discontinuous density gradient, implanted in the spleen. RESULTS: The animals with autotransplant and those with allografts with immunosuppression that became normoglycemic showed altered results of intravenous tolerance glucose (p < 0.001) and peripheral and splenic vein plasmatic insulin levels were significantly lower (p < 0.001) in animals that had allografts with immunosuppression than in those with just autotransplants. CONCLUSIONS: In the animals with immunosupression with cyclosporine subjected to allograft of pancreatic islets prepared with the mechanical-enzymatic preparation method (stationary collagenase digestion and purification with dextran discontinuous density gradient), the production of insulin is decreased and the response to intravenous glucose is altered.

OBJETIVO: Avaliar o comportamento funcional do alotransplante com imunossupressão de ilhotas pancreáticas no baço. MÉTODOS: Foram utilizados cinco grupos de 10 cães mestiços: grupo A (controle) submetido aos exames bioquímicos; grupo B, submetido à pancreatectomia total; grupo C (autotransplante) submetido à pancreatectomia total e autotransplantação de ilhotas pancreáticas no baço; grupo D, submetido à alotransplantação de ilhotas pancreáticas no baço sem terapia imunossupressiva; grupo E, submetido à alotransplantação de ilhotas no baço e imunossupressão com ciclosporina. Todos os animais transplantados receberam ilhotas pancreáticas isoladas pelo método mecânico-enzimático, digestão estacionária com colagenase e purificação com gradiente de densidade descontínua de dextran e foram implantadas no baço. RESULTADOS: Animais autotransplantados e alotransplantados com imunossupressão que se tornaram normoglicêmicos apresentaram testes de tolerância à glicose intravenosa alterados (p<0,001) e o nível de insulina plasmática periférica e na veia esplênica foram significantemente menores (p<0,001) nos animais alotransplantados com imunossupressão em relação aos autotransplantados. CONCLUSÃO: Nos animais submetidos ao alotransplante de ilhotas pancreáticas com imunossupressão com ciclosporina e preparadas pelo método mecânico-enzimático, digestão estacionária com colagenase e purificação com gradiente de densidade descontínua de dextran, a produção de insulina está diminuída e a resposta à sobrecarga de glicose intravenosa alterada.

Atualização no transplante de pâncreas / Pancreas transplantation: an overview

Pancreas transplantation is the only treatment able to reestablish normal glucose and glycated hemoglobin levels in insulin-dependent diabetic patients without the use of exogenous insulin. The evolution of pancreas transplantation in treatment of diabetes was determined by advances in the s of surgical technique, organ preservation and immunosuppressants. The main complication leading to graft loss is technical failure followed by acute or chronic rejection. Technical failure means graft loss within the first three months following transplantation due to vascular thrombosis (50%), pancreatitis (20%), infection (18%), fistula (6.5%) and bleeding (2.4%). Immunological complications still affect 30% of patients, and rejection is the cause of graft loss in 10% of cases. Chronic rejection is the most common late complication. Cardiovascular diseases are the most common causes of late mortality in pancreas transplantation, so it remains the most effective treatment for type 1 diabetes patients. There is a significant improvement in quality of life and in patient's survival rates. The development of islet transplantation could eliminate or minimize surgical complications and immunosuppression.

O transplante de pâncreas é o único tratamento capaz de restabelecer os níveis de glicose e hemoglobina glicada em pacientes diabéticos dependentes de insulina, sem o uso de insulina exógena. A evolução do transplante de pâncreas no tratamento de diabetes foi marcada por avanços nos campos da técnica cirúrgica, preservação de órgãos e imunossupressão. A principal complicação da perda do enxerto é a falha técnica, seguida de rejeição aguda ou crônica. Por falha técnica entende-se perda do enxerto dentro dos primeiros três meses seguintes ao transplante devido a: trombose vascular (50%), pancreatite (20%), infecção (18%), fístula (6,5%) e hemorragia (2,4%). Complicações imunológicas ainda afetam 30% dos pacientes, e a rejeição causa perda do enxerto em 10% dos casos. A rejeição crônica é a complicação tardia mais comum. Doenças cardiovasculares são a causa mais frequente de mortalidade tardia no transplante de pâncreas que continua sendo o tratamento mais eficaz para pacientes com diabetes do tipo 1. Há uma importante melhora na qualidade de vida e na sobrevida dos pacientes. O desenvolvimento de ilhotas transplantadas pode eliminar ou minimizar complicações cirúrgicas e a imunossupressão.

Estimation of expanded criteria donor usability for islet isolation / 中华器官移植杂志

Objective Islet transplantation has been an effective method for diabetes mellitus. The quality of donor pancreas is important for successful islet isolation. In this study, we evaluated expanded criteria donor usability based on the warm ischemic time, fatty pancreas and perfusion injury. Methods The marginal pancreases include those from cardiac death donor, fatty pancreas and edema pancreas from perfusion injury. Islets were isolated and purified using a modified University of Minnesota method. Islet yield and purity was determined by Dithizone (DTZ) staining and microscopic examination. Islet viability was assessed by AO/EB staining, and islet function was assessed by static glucose stimulation test. Results In the cardiac death donor group, the islet quality, viability, and in vitro function were similar when the warm ischemic time within 15 min. The quality and viability was decreased when the warm ischemic time beyond 30 min, but the function remained well. With 45 min warm ischemic time, insulin release index was decreased significantly. The islet quality, viability, and in vitro function from severe obesity group and severe edema group were decreased obviously. Conclusion Donor factors play a vital role in pancreas transplant outcomes. We concluded that pancreas severe obesity, severe edema and pancreas from cardiac donors (warm ischemic time ＞30 min) are unsuitable for islet isolation.

The effect of mouse bone marrow-derived mesenchymal stem cells on islet graft rejection / 中华器官移植杂志

Objective To investigate the immune regulatory effects of allogeneic bone marrowderived mesenchyrnal stem cells (MSCs) co-transplanted with islets. Methods The 18 diabetic mice were randomly divided into 3 groups: Diabetic group, without any transplantation; Islet transplantation group, in a sterile operation, with 10 μl purified islets (about 200 islets)transplantation to the left renal subcapsule of recipients; Islet + MSCs transplantation group, in addition to transplantation as the former group, 1 × 106 MSCs were given to the recipients via tail vein on 3, 2 and 0 days before islet transplantation. Blood glucose in recipient mice was monitored for 30consecutive days after transplantation. Pathological characteristics of left kidney were analyzed on the day 14 and 28 after transplantation. Th1/Th2, Tc1/Tc2, naive and memory T cells from peripheral blood and bone marrow-derived dendritic cells (DCs) were analyzed by multi-color flow cytometry.Results As compared with the islet transplantation group, blood glucose was significantly reduced,inflammatory cell infiltration decreased in the place of transplantation, graft survival prolonged, the number of Th1 and Tc1 cells was obviously reduced, the number of Th2 and Tc2 cells increased, the ratio of Th1/Th2 and Tc1/Tc2 cells was significantly decreased, the naive and memory T cells were significantly inhibited, the maturity of DCs and the secretion of interleukin-12 decreased in the islet transplantation group. Conclusion Through the immunomodulation on T-cell and DCs function,MSCs can alleviate graft verse host disease and prolong allograft survival.