Global scientific trends on the islet transplantation in the 21st century: A bibliometric and visualized analysis.

BACKGROUND: Islet transplantation (IT) has emerged as a significant research area for the treatment of diabetes mellitus and has witnessed a surge in scholarly attention. Despite its growing importance, there is a lack of bibliometric analyses that encapsulate the evolution and scientific underpinnings of this field. This study aims to fill this gap by conducting a comprehensive bibliometric analysis to delineate current research hotspots and forecast future trajectories within the IT domain with a particular focus on evidence-based medicine practices. METHODS: This analysis scrutinized literature from January 1, 2000, to October 1, 2023, using the Web of Science Core Collection (WoSCC). Employing bibliometric tools such as VOSviewer, CiteSpace, and the R package "bibliometrix," we systematically evaluated the literature to uncover scientific trends and collaboration networks in IT research. RESULTS: The analysis revealed 8388 publications from 82 countries, predominantly the United States and China. However, global cross-institutional collaboration in IT research requires further strengthening. The number of IT-related publications has increased annually. Leading research institutions in this field include Harvard University, the University of Alberta, the University of Miami, and the University of Minnesota. "Transplantation" emerges as the most frequently cited journal in this area. Shapiro and Ricordi were the most prolific authors, with 126 and 121 publications, respectively. Shapiro also led to co-citations, totaling 4808. Key research focuses on IT sites and procedures as well as novel therapies in IT. Emerging research hotspots are identified by terms like "xenotransplantation," "apoptosis," "stem cells," "immunosuppression," and "microencapsulation." CONCLUSIONS: The findings underscore a mounting anticipation for future IT research, which is expected to delve deeper into evidence-based methodologies for IT sites, procedures, and novel therapeutic interventions. This shift toward evidence-based medicine underscores the field's commitment to enhancing the efficacy and safety of IT for diabetes treatment, signaling a promising direction for future investigations aimed at optimizing patient outcomes.

The Association of Smoking and Alcohol Abuse on Anxiety and Depression in Patients With Recurrent Acute or Chronic Pancreatitis Undergoing Total Pancreatectomy and Islet Autotransplantation: A Report From the Prospective Observational Study of TPIAT Cohort.

OBJECTIVES: Smoking and alcohol use are risk factors for acute and chronic pancreatitis, and their role on anxiety, depression, and opioid use in patients who undergo total pancreatectomy and islet autotransplantation (TPIAT) is unknown. METHODS: We included adults enrolled in the Prospective Observational Study of TPIAT (POST). Measured variables included smoking (never, former, current) and alcohol abuse or dependency history (yes vs no). Using univariable and multivariable analyses, we investigated the association of smoking and alcohol dependency history with anxiety and depression, opioid use, and postsurgical outcomes. RESULTS: Of 195 adults studied, 25 were current smokers and 77 former smokers, whereas 18 had a history of alcohol dependency (of whom 10 were current smokers). A diagnosis of anxiety was associated with current smoking (P = 0.005), and depression was associated with history of alcohol abuse/dependency (P = 0.0001). However, active symptoms of anxiety and depression at the time of TPIAT were not associated with smoking or alcohol status. Opioid use in the past 14 days was associated with being a former smoker (P = 0.005). CONCLUSIONS: Active smoking and alcohol abuse history were associated with a diagnosis of anxiety and depression, respectively; however, at the time of TPIAT, symptom scores suggested that they were being addressed.

A Study on the Effect of Patient Characteristics, Geographical Utilization, and Patient Outcomes for Total Pancreatectomy Alone and Total Pancreatectomy With Islet Autotransplantation in Patients With Pancreatitis in the United States.

OBJECTIVES: A selective therapy for pancreatitis is total pancreatectomy and islet autotransplantation. Outcomes and geographical variability of patients who had total pancreatectomy (TP) alone or total pancreatectomy with islet autotransplantation (TPIAT) were assessed. METHODS: Data were obtained from the Healthcare Cost and Utilization Project National Inpatient Sample database. Weighed univariate and multivariate analyses were performed to determine the effect of measured variables on outcomes. RESULTS: Between 2002 and 2013, there were 1006 TP and 825 TPIAT in patients with a diagnosis of chronic pancreatitis, and 1705 TP and 830 TPIAT for any diagnosis of pancreatitis. The majority of the TP and TPIAT were performed in larger urban hospitals. Costs were similar for TP and TPIAT for chronic pancreatitis but were lower for TPIAT compared with TP for any type of pancreatitis. The trend for TP and TPIAT was significant in all geographical areas during the study period. CONCLUSIONS: There is an increasing trend of both TP and TPIAT. Certain groups are more likely to be offered TPIAT compared with TP alone. More data are needed to understand disparities and barriers to TPIAT, and long-term outcomes of TPIAT such as pain control and glucose intolerance need further study.

Validation of a New North American Islet Donor Score for Donor Pancreas Selection and Successful Islet Isolation in a Medium-Volume Islet Transplant Center.

The selection of optimal pancreas donors is one of the key factors in determining the ultimate outcome of clinical islet isolation. North American Islet Donor Score (NAIDS) allows for estimating the chance of the success of islet isolation. It was developed based on the data from over 1000 donors from 11 islet isolation centers and validated in the University of Alberta, Edmonton, on the cohort from the most active islet transplant center. Now we aimed to also validate it in our much less active program. Areas under the receiver operating characteristic curves (AUROCs) and logistic regression analyses were obtained to test if NAIDS would better predict successful islet isolation (defined as post-purification islet yield >400,000 islet equivalents (IEQ)) than previously described Edmonton islet donor score (IDS) and our modified version of IDS. We analyzed the donor scores with reference to 82 of our islet isolation outcomes. The success rate increased proportionally as NAIDS increased, from 0% success in NAIDS < 50 points to 40% success in NAIDS ≥ 80 points. AUROCs were 0.67 (95% confidence interval (CI) 0.55-0.79) for NAIDS, 0.58 (95% CI 0.44-0.71) for modified IDS, and 0.51 (95% CI 0.37-0.65) for IDS and did not differ significantly. However, based on logistic regression analyses, NAIDS was the only statistically significant predictor of successful isolation (p = 0.01). The main advantage of NAIDS is an enhanced ability to discriminate poor-quality donors than previously used scoring systems at University of Chicago, with 0% chance for success when NAIDS was <50 as compared with 40% success rate for IDS <50. NAIDS was found to be the most useful available tool for donor pancreas selection in clinical and research practice in our center, allowing for identification and rejection of poor-quality donors, saving time and resources.

Pediatric chronic pancreatitis: Updates in the 21st century.

Pediatric Pancreatitis has gained a lot of attention in the last decade. Updates in medical management include new testing technologies in genetics, function testing and imaging modalities. Updates in surgical management have taken place as well, with total pancreatectomy islet auto transplantation reserved for a specific patient population that meets the clinical criteria. Multidisciplinary team management is needed for patients with chronic pancreatitis to ensure optimal outcomes.

Pancreas preservation fluid microbial contamination is associated with poor islet isolation outcomes - a multi-centre cohort study.

The microbiological safety of islet preparations is paramount. Preservation medium contamination is frequent, and its impact on islet yield and function remains unclear. Microbiological samples collected during islet isolations from 2006 to 2016 were analyzed and correlated to isolation and allo- and autotransplantation outcomes. Microbial contamination of preservation medium was found in 64.4% of processed donor pancreases (291/452). We identified 464 microorganisms including Staphylococcus (253/464, 54.5%), Streptococcus (31/464, 6.7%), and Candida species (25/464, 5.4%). Microbial contamination was associated with longer warm and cold ischemia times and lower numbers of postpurification islet equivalents, purity, transplant rate, and stimulation index (all P < 0.05). Six percent of the preparations accepted for transplantation showed microbial contamination after isolation (12/200); 9 of 12 were Candida species. Six patients were transplanted with a sample with late microbial growth discovered after the infusion. Insulin independence rate was not affected. This risk of transplanting a contaminated islets preparation was reduced by half following the implementation of an additional sampling after 24 h of islet culture. Pancreas preservation fluid microbial contamination is associated with lower transplant rate and poorer in vitro function, but not with changes in graft survival. Culture medium testing 1 day after isolation reduces the risk of incidental transplantation with contaminated islets.

Clinical Islet Transplantation for Adults With Type 1 Diabetes in Canada: Referral Patterns and Eligibility Assessment.

OBJECTIVES: Careful selection for clinical islet transplantation (CIT) is required because of limited organ supply and the risks for lifelong immunosuppression. However, the indications for this novel treatment may not be widely known, and selection criteria continue to evolve. We sought to describe the pattern of referrals to our centre and the most common factors determining eligibility for CIT. METHODS: We performed a retrospective chart review of all applications for CIT received at the University of Alberta between May 2009 and April 2012. Demographics and clinical data were abstracted along with the sources of referral. Application results and reasons for eligibility or ineligibility were determined. For ineligible subjects, the primary reason for ineligibility was noted. RESULTS: We received 246 applications (mean age 43; range, 13 to 78 years; 54% male) from across Canada. The majority (81%) were self-referrals, with the remainder coming from specialists (15%) or primary care physicians (4%). Of the applicants, 19% were deemed eligible and were accepted for waitlisting. Acceptance rates were not different between physician referrals and self-referrals (25% vs. 18%; p=ns). The main reasons for ineligibility were no indication (39%); contraindications (metabolic, 21%; medical comorbidity, 17%; psychosocial, 8%) or personal factors (15%). CONCLUSIONS: Most referrals were received from people with diabetes, but acceptance rates were not significantly lower than for physician referrals. It will be important to increase awareness of severe hypoglycemia or glycemic lability as major indications for CIT among patients and physicians and to evaluate any impact this may have on the current acceptance rate of 19%.

Human islet xenotransplantation in rodents: A literature review of experimental model trends.

Among the innovations for the treatment of type 1 diabetes, islet transplantation is a less invasive method of treatment, although it is still in development. One of the greatest barriers to this technique is the low number of pancreas donors and the low number of pancreases that are available for transplantation. Rodent models have been chosen in most studies of islet rejection and type 1 diabetes prevention to evaluate the quality and function of isolated human islets and to identify alternative solutions to the problem of islet scarcity. The purpose of this study is to conduct a review of islet xenotransplantation experiments from humans to rodents, to organize and analyze the parameters of these experiments, to describe trends in experimental modeling and to assess the viability of this procedure. In this study, we reviewed recently published research regarding islet xenotransplantation from humans to rodents, and we summarized the findings and organized the relevant data. The included studies were recent reports that involved xenotransplantation using human islets in a rodent model. We excluded the studies that related to isotransplantation, autotransplantation and allotransplantation. A total of 34 studies that related to xenotransplantation were selected for review based on their relevance and current data. Advances in the use of different graft sites may overcome autoimmunity and rejection after transplantation, which may solve the problem of the scarcity of islet donors in patients with type 1 diabetes.

Human islet xenotransplantation in rodents: A literature review of experimental model trends

Among the innovations for the treatment of type 1 diabetes, islet transplantation is a less invasive method of treatment, although it is still in development. One of the greatest barriers to this technique is the low number of pancreas donors and the low number of pancreases that are available for transplantation. Rodent models have been chosen in most studies of islet rejection and type 1 diabetes prevention to evaluate the quality and function of isolated human islets and to identify alternative solutions to the problem of islet scarcity. The purpose of this study is to conduct a review of islet xenotransplantation experiments from humans to rodents, to organize and analyze the parameters of these experiments, to describe trends in experimental modeling and to assess the viability of this procedure. In this study, we reviewed recently published research regarding islet xenotransplantation from humans to rodents, and we summarized the findings and organized the relevant data. The included studies were recent reports that involved xenotransplantation using human islets in a rodent model. We excluded the studies that related to isotransplantation, autotransplantation and allotransplantation. A total of 34 studies that related to xenotransplantation were selected for review based on their relevance and current data. Advances in the use of different graft sites may overcome autoimmunity and rejection after transplantation, which may solve the problem of the scarcity of islet donors in patients with type 1 diabetes.

[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.

Spontaneous Hypoglycemia After Islet Autotransplantation for Chronic Pancreatitis.

CONTEXT: Spontaneous hypoglycemia has been reported in patients after total pancreatectomy (TP) and islet autotransplantation (IAT) with maintained insulin independence. Details surrounding these events have not been well described. OBJECTIVE: The objective of the study was to determine the frequency and characteristics of spontaneous hypoglycemia in patients undergoing TP-IAT and/or to ascertain predictive or protective factors of its development. DESIGN: This was an observational cohort study in 40 patients who underwent TP-IAT from August 2008 to May 2014, with a median follow-up of 34 months. SETTING: The study was conducted at a single institution (Cleveland Clinic). PATIENTS: Patients included recipients of TP-IAT. INTERVENTION: The intervention included small, frequent meals in those patients who developed spontaneous hypoglycemia. MAIN OUTCOME MEASURES: Incidence of spontaneous hypoglycemia development, characteristics of the patients developing hypoglycemia, and their response to small, frequent meals were measured. RESULTS: Six of 12 patients, who maintained insulin independence, developed spontaneous hypoglycemia. The episodes could be fasting, postprandial, and/or exercise associated, with the frequency ranging from two to three times daily to once every 1-2 weeks. All patients experienced at least one episode that required external assistance, glucagon administration, and/or emergent medical attention. Patients who developed hypoglycemia had a lower median age and tended to have a lower median islet equivalent/kg body weight but a higher median total islet equivalent, body mass index, and homeostatic model assessment for insulin resistance score. All patients who received small, frequent meal intervention had improvement in severity and/or frequency of the hypoglycemic episodes. CONCLUSIONS: Spontaneous hypoglycemia is prevalent after TP-IAT. Although the underlying pathophysiology responsible for these hypoglycemia events remains to be elucidated, small, frequent meal intervention is helpful in ameliorating this condition.

Cost effectiveness and value of information analyses of islet cell transplantation in the management of 'unstable' type 1 diabetes mellitus.

BACKGROUND: Islet cell transplantation is a method to stabilize type 1 diabetes patients with hypoglycemia unawareness and unstable blood glucose levels by reducing insulin dependency and protecting against severe hypoglycemia through restoring endogenous insulin secretion. This study analyses the current cost-effectiveness of this technology and estimates the value of further research to reduce uncertainty around cost-effectiveness. METHODS: We performed a cost-utility analysis using a Markov cohort model with a mean patient age of 49 to simulate costs and health outcomes over a life-time horizon. Our analysis used intensive insulin therapy (IIT) as comparator and took the provincial healthcare provider perspective. Cost and effectiveness data for up to four transplantations per patient came from the University of Alberta hospital. Costs are expressed in 2012 Canadian dollars and effectiveness in quality-adjusted life-years (QALYs) and life years. To characterize the uncertainty around expected outcomes, we carried out a probabilistic sensitivity analysis within the Bayesian decision-analytic framework. We performed a value-of-information analysis to identify priority areas for future research under various scenarios. We applied a structural sensitivity analysis to assess the dependence of outcomes on model characteristics. RESULTS: Compared to IIT, islet cell transplantation using non-generic (generic) immunosuppression had additional costs of $150,006 ($112,023) per additional QALY, an average gain of 3.3 life years, and a probability of being cost-effective of 0.5 % (28.3 %) at a willingness-to-pay threshold of $100,000 per QALY. At this threshold the non-generic technology has an expected value of perfect information (EVPI) of $260,744 for Alberta. This increases substantially in cost-reduction scenarios. The research areas with the highest partial EVPI are costs, followed by natural history, and effectiveness and safety. CONCLUSIONS: Current transplantation technology provides substantial improvements in health outcomes over conventional therapy for highly selected patients with 'unstable' type 1 diabetes. However, it is much more costly and so is not cost-effective. The value of further research into the cost-effectiveness is dependent upon treatment costs. Further, we suggest the value of information should not only be derived from current data alone when knowing that this data will most likely change in the future.

Positive sterility cultures of transplant solutions during pancreatic islet autotransplantation are associated infrequently with clinical infection.

BACKGROUND: Chronic pancreatitis is a painful and often debilitating disease. Total pancreatectomy with intra-portal islet autotransplantation (TP-IAT) is a treatment option that allows for pain relief and preservation of beta-cell mass, thereby minimizing the complication of diabetes mellitus. Cultures of harvested islets are often positive for bacteria, possibly due to frequent procedures prior to TP-IAT, such as endoscopic retrograde cholangiopancreatography (ERCP), stenting, or other operative drainage procedures. It is unclear if these positive cultures contribute to post-operative infections. HYPOTHESIS: We hypothesized that positive cultures of transplant solutions will not be associated with increased infection risk. METHODS: We reviewed retrospectively the sterility cultures from both the pancreas preservation solution used to transport the pancreas and the final islet preparation for intra-portal infusion of patients who underwent TP-IAT between April 2006 and November 2012. Two hundred fifty-one patients underwent total, near-total, or completion pancreatectomy with IAT and had complete sterility cultures. All patients received prophylactic peri-operative antibiotics. Patients with positive pancreas preservation solution or islet sterility cultures received further antibiotics for 5-7 d. Patients' medical records were reviewed for post-operative infections and causative organisms. RESULTS: Of the 251 patients included, 151 (61%) had one or more positive bacterial cultures from the pancreas preservation solution or final islet product. Seventy-three of the 251 patients (29%) had an infectious complication. Thirty-four of the 73 (22%) patients with a post-operative infectious complication also had positive cultures. Only seven of 151 patients with positive cultures (4.7%) had an infectious complication caused by the same organism as that isolated from their pancreas or islet cell preparation. CONCLUSIONS: In autologous islet preparations, isolation solutions frequently have positive cultures, but this finding is associated infrequently with clinical infection.

Has the gap between pancreas and islet transplantation closed?

Both pancreas and islet transplantations are therapeutic options for complicated type 1 diabetes. Until recent years, outcomes of islet transplantation have been significantly inferior to those of whole pancreas. Islet transplantation is primarily performed alone in patients with severe hypoglycemia, and recent registry reports have suggested that results of islet transplantation alone in this indication may be about to match those of pancreas transplant alone in insulin independence. Figures of 50% insulin independence at 5 years for either procedure have been cited. In this article, we address the question whether islet transplantation has indeed bridged the gap with whole pancreas. Looking at the evidence to answer this question, we propose that although pancreas may still be more efficient in taking recipients off insulin than islets, there are in fact numerous "gaps" separating both procedures that must be taken into the equation. These "gaps" relate to organ utilization, organ allocation, indication for transplantation, and morbidity. In-depth analysis reveals that islet transplantation, in fact, has an edge on whole pancreas in some of these aspects. Accordingly, attempts should be made to bridge these gaps from both sides to achieve the same level of success with either procedure. More realistically, it is likely that some of these gaps will remain and that both procedures will coexist and complement each other, to ensure that ß cell replacement can be successfully implemented in the greatest possible number of patients with type 1 diabetes.

Islet of Langerhans isolation from pediatric and juvenile donor pancreases.

Islet grafts isolated from young donors allow superior functional outcomes but are often associated with poor islet isolation yields. The objective of this study was to comparatively analyze the outcomes of islet isolation between young and older donors. We retrospectively analyzed 564 pancreas isolations performed at our institution. Isolation outcomes were compared between donors aged ≤20 years (n = 42, YD) and >20 years (n = 522, OD). Isolation procedure was identical in both groups. Prepurification percentage of embedded islets was higher in YD (44.3 ± 22.7% vs. 24.9 ± 20.9%, P < 0.001). This led to a lower recovery rate in YD (48% vs. 76%, P = 0.002) and hence lower postpurification IEQ/g pancreas in YD (2 412 ± 1 789 IEQ/g vs. 3 194 ± 1 892 IEQ/g, P = 0.01). Final yield was 180 982 ± 128 073 IEQ in YD and 244 167 ± 134 137 IEQ in OD, (P = 0.006). In vitro function was markedly, albeit nonsignificantly, higher in YD (SI: 4.5 ± 5.1 vs. 3.0 ± 5.7, P = 0.350). Proportion of transplanted preparations was similar in both groups, 38% (16/42) in YD vs. 43% (224/522) in OD, P = 0.628. In spite of isolation and purification difficulties, pancreases from young donors allowed similar islet transplantation rates as older donors. Efforts should be directed at improving islet extraction in these donors to realize their full potential for islet transplantation.

The allocation of pancreas allografts on donor age and duration of intensive care unit stay: the experience of the North Italy Transplant program.

Starting in 2011, the North Italy Transplant program (NITp) has based on the allocation of pancreas allografts on donor age and duration of intensive care unit (ICU) stay, but not on donor weight or BMI. We analyzed the detailed allocation protocols of all NITp pancreas donors (2011-2012; n = 433). Outcome measures included donor characteristics and pancreas loss reasons during the allocation process. Twenty-three percent of the 433 pancreases offered for allocation were transplanted. Younger age, shorter ICU stay, traumatic brain death, and higher eGFR were predictors of pancreas transplant, either as vascularized organ or as islets. Among pancreas allografts offered to vascularized organ programs, 35% were indeed transplanted, and younger donor age was the only predictor of transplant. The most common reasons for pancreas withdrawal from the allocation process were donor-related factors. Among pancreas offered to islet programs, 48% were processed, but only 14.2% were indeed transplanted, with unsuccessful isolation being the most common reason for pancreas loss. Younger donor age and higher BMI were predictors of islet allograft transplant. The current allocation strategy has allowed an equal distribution of pancreas allografts between programs for either vascularized organ or islet transplant. The high rate of discarded organs remained an unresolved issue.

Pseudoislets as primary islet replacements for research: report on a symposium at King's College London, London UK.

Laboratory-based research aimed at understanding processes regulating insulin secretion and mechanisms underlying ß-cell dysfunction and loss in diabetes often makes use of rodents, as these processes are in many respects similar between rats/mice and humans. Indeed, a rough calculation suggests that islets have been isolated from as many as 150,000 rodents to generate the data contained within papers published in 2009 and the first four months of 2010. Rodent use for islet isolation has been mitigated, to a certain extent, by the availability of a variety of insulin-secreting cell lines that are used by researchers world-wide. However, when maintained as monolayers the cell lines do not replicate the robust, sustained secretory responses of primary islets which limits their usefulness as islet surrogates. On the other hand, there have been several reports that configuration of MIN6 ß-cells, derived from a mouse insulinoma, as three-dimensional cell clusters termed 'pseudoislets' largely recapitulates the function of primary islet ß-cells. The Diabetes Research Group at King's College London has been using the MIN6 pseudoislet model for over a decade and they hosted a symposium on "Pseudoislets as primary islet replacements for research", which was funded by the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs), in London on 15th and 16th April 2010. This small, focused meeting was conceived as an opportunity to consolidate information on experiences of working with pseudoislets between different UK labs, and to introduce the theory and practice of pseudoislet culture to laboratories working with islets and/or ß-cell lines but who do not currently use pseudoislets. This short review summarizes the background to the development of the cell line-derived pseudoislet model, the key messages arising from the symposium and emerging themes for future pseudoislet research.

Islet transplantation using donors after cardiac death: report of the Japan Islet Transplantation Registry.

BACKGROUND: This report summarizes outcomes of islet transplantation employing donors after cardiac death (DCD) between 2004 and 2007 as reported to the Japan Islet Transplantation Registry. METHOD: Sixty-five islet isolations were performed for 34 transplantations in 18 patients with insulin-dependent diabetes mellitus, including two patients who had prior kidney transplantation. All but one donor (64/65) was DCD at the time of harvesting. RESULTS: Factors influencing criteria for islet release included duration of low blood pressure of the donor, cold ischemic time, and usage of Kyoto solution for preservation. Multivariate analysis selected usage of Kyoto solution as most important. Of the 18 recipients, 8, 4, and 6 recipients received 1, 2, and 3 islet infusions, respectively. Overall graft survival defined as C-peptide level more than or equal to 0.3 ng/mL was 76.5%, 47.1%, and 33.6% at 1, 2, and 3 years, respectively, whereas corresponding graft survival after multiple transplantations was 100%, 80.0%, and 57.1%, respectively. All recipients remained free of severe hypoglycemia while three achieved insulin independence for 14, 79, and 215 days. HbA1c levels and requirement of exogenous insulin were significantly improved in all patients. CONCLUSION: Islet transplantation employing DCD can ameliorate severe hypoglycemic episodes, significantly improve HbA1c levels, sustain significant levels of C-peptide, and achieve insulin independence after multiple transplantations. Thus, DCD can be an important resource for islet transplantation if used under strict releasing criteria and in multiple transplantations, particularly in countries where heart-beating donors are not readily available.

International human xenotransplantation inventory.

BACKGROUND: Xenotransplantation carries inherent risks of infectious disease transmission to the recipient and even to society at large, and it should only be carried out with strict regulation and oversight. In collaboration with the International Xenotransplantation Association, the University Hospital Geneva, and the World Health Organization, an international inventory has been established (www.humanxenotransplant.org) aiming to collect basic data on all types of currently ongoing or recently performed xenotransplantation procedures in humans. METHODS: We collected information from publications in scientific journals, presentations at international congresses, the internet, and declarations of International Xenotransplantation Association members on xenotransplantation procedures in humans performed during the past 15 years. RESULTS: We identified a total of 29 human applications of xenotransplantation, including 7 that were currently ongoing. Procedures involved transplantation of xenogeneic cells, i.e., islets of Langerhans, kidney cells, chromaffin cells, embryonic stem cells, fetal and adult cells from various organs or extracorporeal perfusion using hepatocytes, liver, spleen, or kidney. The treatments were performed in 12 different countries, 9 of them having no national regulation on xenotransplantation. CONCLUSION: Several clinical applications of cell xenotransplantation are ongoing around the world, often without any clear governmental regulation. This information should be used to inform national health authorities, healthcare staff, and the public, with the objective of encouraging good practices, with internationally harmonized guidelines and regulation of xenotransplantation.

Isolation and purification of islet cells from adult pigs.

We used in situ perfusion and a multiple-organ harvesting technique to collect islets from adult pig pancreata. The tissues were digested with collagenase P followed by purification in a lympholyte discontinuous gradient using a COBE2991 cell separator. The yield and purity of isolated islets were evaluated with a light microscope after dithizone (DTZ) staining. Islet function was assessed using an in vitro insulin release assay. The results showed that before purification 275,000 +/- 20,895 islet equivalents (IEQ) were obtained from 1 digested pancreas. After purification with gradient centrifugation, the islet yield was 230,350 +/- 26,679 IEQ/pancreas. Each gram of the purified pancreatic tissues yielded 2710 +/- 229 IEQ with an average purity of 50.2 +/- 2.0%. The purified islet cells responded to stimulation with high glucose concentrations (16.7 mmol/L), namely, 4.74-fold greater than the insulin secretion with exposure to the basal level of glucose (3.3 mmol/L; P < .001). These results suggested that the established isolation method can be applied to large-scale purification of fully functional islets from pig pancreata.