Clinical Islet Transplantation: Where Do We Stand on? / 대한이식학회지

Islet transplantation had been suggested as a potential treatment modality for type I diabetes mellitus for the last two decades. The methods for the islet isolation and purification were developed. In 2000, the excellent clinical outcomes from the Edmonton group were reported. And various basic researches were performed for the elucidation of the mechanism of initial islet loss. Although the Edmonton protocol, which had initially raised hopes that all the technical and immunologic problems would be solved, recently revealed as a limited success within the selective cases and short-term follow-up, these inspirations led us to the subsequent clinical or basic research of islet transplantation. As a result, many clinical trials and studies have been attempted for the establishment of the optimal immune suppression regimen, the prevention from islet loss in the process of isolation, and the improvement of the intraportal engraftment. This article reviews the history and the recent progress and possible strategies for the clinical islet transplantation.

Pancreas Islet Cell Transplantation: Present and Future / 한양의대학술지

Pancreas islet cell transplantation has been regarded as an ideal method to treat the type I diabetes mellitus. However, it could not be the method of choice because of poor graft survival rate after transplantation. Recently, the outcome of pancreas islet cell transplantation has been improving, especially since the Edmonton group has succeeded in controlling the glucose metabolism in 7 consecutive type I diabetes mellitus patients. Returning to diabetic status in a substantial portion of transplanted patients, however, has revealed that lots of hurdles, such as primary non-function of the islet from non-specific inflammation, immunologic destruction of islets from either allogenic or autoimmune process, and shortage of donor source, remained to be solved in the near future, if pancreas islet cell transplantation is to be a practical clinical treatment modality for diabetic patients. We herein discuss on the current status and future of pancreas islet cell transplantation.

Comparative Study on Biologic and Immunologic Characteristics of the Pancreas Islet Cell between 24degrees C and 37degrees C Culture in the Rat / 대한이식학회지

PURPOSE: Islet cell transplantation, as an alternative approach to endocrine cell replacement to treat the diabetes mellitus, has received significant attention because it holds several advantages over whole gland transplantation. However cell damage from islet isolation and immunologic rejection after transplantation prevent from successful clinical application for diabetic patients. Culture of cells at low temperature has known to stabilize the cell viability, and to decrease the immunologic antigenicity. Aim of this study is to investigate the effect of culture at 24oC on cell viability, cellular function, immunogenicity and cytokine profiles in rat pancreas islet. METHODS: Pancreas islets were isolated from Lewis rat and cultured at 24oC or 37oC during 14 days. Islet recovery after culture period was counted as islet equivalent number, and islet viability was examined with fluorescent vital staining (FDA/PI). Islet function was measured with glucose stimulation test. Annexin V expression and MHC class I and II expression were measured with flow cytometric assay for apoptosis and immunogenicity respectively. Lymphocyte cell proliferation through mixed lymphocyte islet culture was examined with WST-1 proliferation assay. Cytokine profiles were analyzed with quantitative real time RT-PCR. All these parameters were measured on 1, 3, 5, 7, 14 culture days after islet isolation. RESULTS: Islet recovery was higher in islet cultured at 24oC than in islet cultured at 37oC without change of viability. Insulin secretion after glucose stimulation was more effective in 24oC culture condition. Decrease of apoptotic cell death was demonstrated in 24oC cultured islet. MHC class I and II expression on islets and lymphocyte proliferation when cocultured with islets were less prominent in 24oC cultured islet. TNF-alpha and IL-4 cytokine expression was higher in islet cultured at 24oC than in islet cultured at 37oC. IL-1beta and IL-10 cytokine expression were similar in both culture condition. CONCLUSION: This study demonstrated that cell recovery and function are increased in islet cultured at 24oC than in islet cultured at 37oC while antigenicity and proinflammatory cytokine expression are decreased. Low temperature culture can be a good approach to prevent the loss of islet mass, and to reduce the immunologic rejection of transplanted islet for successful clinical islet transplantation.

In Vitro Analysis of Co-cultured Pancreatic Islet with Lymphocyte / 대한이식학회지

BACKGROUND: Transplantation of Pancreatic islet represents one of the most exciting treatment modalities for Type I diabetes mellitus. To achieve better graft survival, it is important to protect the graft from alloantigen-specific immune response. It was emphasized that islets, as with other forms of cellular transplants, have the potential advantage of being immunologically altered before transplantation, resulting in tolerance to the host without using long-term, nonspecific immunosuppression. The mixed islet-lymphocyte culture is an excellent tool to evaluate the immunogenicity of a pancreatic islets. Therefore, we co-cultured pancreatic islet and lymphocyte to investigate cytokine gene expression from the lymphocyte, and to investigate pancreatic islet viability and functional changes after co-culture. MATERIALS AND METHODS: Lewis rat islets were purified from pancreas by collagenase type XI and dextran gradient method. Afterwards, Lewis rat islets were co-cultured as a stimulator and Wistar rat lymphocyte as a reponder. As a control group lymphocyte alone and islet alone were cultured in a same condition. For estimating islets viability, we counted islet viability as an IEQ (Islet equivalent). For evaluation of islets function, insulin release assay was perfomed by RIA under the glucose challenge. used by RIA. We studied cytokines gene expression of cultured cells by reverse transcriptase polymerase chain reaction (RT-PCR). RESULT AND CONCLUSION: 1) Islet yield was 1229.8 420.1 per rat, and counted as 2615.4 548.2 IEQ per rat. 2) Islet viability was decreased gradually with the lapse of time, more rapid in allogenic co-culture group than islet alone or isogenic co-culture group. 3) Release of insulin increased until day 3, and then decreased gradually. Insulin release was positively correlated with glucose gradient. The amount of released insulin was greater in co-cultured group than islet alone group. 4) Interleukine-2 and interferron-gamma gene expression increased in allo co-culture group, however transforming growth factor-beta gene expression was not affected by co-culture.

In Vitro Analysis of Co-cultured Pancreatic Islet with Lymphocyte / 대한이식학회지

BACKGROUND: Transplantation of Pancreatic islet represents one of the most exciting treatment modalities for Type I diabetes mellitus. To achieve better graft survival, it is important to protect the graft from alloantigen-specific immune response. It was emphasized that islets, as with other forms of cellular transplants, have the potential advantage of being immunologically altered before transplantation, resulting in tolerance to the host without using long-term, nonspecific immunosuppression. The mixed islet-lymphocyte culture is an excellent tool to evaluate the immunogenicity of a pancreatic islets. Therefore, we co-cultured pancreatic islet and lymphocyte to investigate cytokine gene expression from the lymphocyte, and to investigate pancreatic islet viability and functional changes after co-culture. MATERIALS AND METHODS: Lewis rat islets were purified from pancreas by collagenase type XI and dextran gradient method. Afterwards, Lewis rat islets were co-cultured as a stimulator and Wistar rat lymphocyte as a reponder. As a control group lymphocyte alone and islet alone were cultured in a same condition. For estimating islets viability, we counted islet viability as an IEQ (Islet equivalent). For evaluation of islets function, insulin release assay was perfomed by RIA under the glucose challenge. used by RIA. We studied cytokines gene expression of cultured cells by reverse transcriptase polymerase chain reaction (RT-PCR). RESULT AND CONCLUSION: 1) Islet yield was 1229.8 420.1 per rat, and counted as 2615.4 548.2 IEQ per rat. 2) Islet viability was decreased gradually with the lapse of time, more rapid in allogenic co-culture group than islet alone or isogenic co-culture group. 3) Release of insulin increased until day 3, and then decreased gradually. Insulin release was positively correlated with glucose gradient. The amount of released insulin was greater in co-cultured group than islet alone group. 4) Interleukine-2 and interferron-gamma gene expression increased in allo co-culture group, however transforming growth factor-beta gene expression was not affected by co-culture.

A Case of Diabetes Mellitus Caused by Calcitonin and Somatostatin Secreting Pancreatic Islet Tumor / 대한내분비학회지

A case of 39-year-old diabetic patient with a calcitonin and somatostatin secreting pancreatic islet tumor is presented. He had suffered from chronic diarrhea and dyspepsia for 10 years and was diagnosed with diabetes 2 years ago. Abdominal CT revealed a huge abdominal mass which was considered as a neuroendocrine tumor after US-guided needle biopsy. A distal pancreatectomy and splenectomy were performed. Histologically, tumor cells, amanged in solid sheets, showed small nuclei without significant atypia and granular eosinophilic cytoplasm. Tumor cells showed strong immunoreacitivity for calcitonin and somatostatin. The serum clacitonin was markedly elevated (268.7 pmol/L, normal range; 0.9-7.6 pmol/L). After resection of the tumor, diarrhea and dyspepsia diappeared, and oral glucose tolerance test showed normal glucose tolerance with normalization of calcitonin.