Systematic review and meta-analysis: islet autotransplantation after pancreatectomy for minimizing diabetes

Cell Therapy for Type 1 Diabetes: From Islet Transplantation to Stem Cells

The field of cell therapy of type 1 diabetes is a particularly interesting example in the scenario of regenerative medicine. In fact, β-cell replacement has its roots in the experience of islet transplantation, which began 40 years ago and is currently a rapidly accelerating field, with several ongoing clinical trials using β cells derived from stem cells. Type 1 diabetes is particularly suitable for cell therapy as it is a disease due to the deficiency of only one cell type, the insulin-producing β cell, and this endocrine cell does not need to be positioned inside the pancreas to perform its function. On the other hand, the presence of a double immunological barrier, the allogeneic one and the autoimmune one, makes the protection of β cells from rejection a major challenge. Until today, islet transplantation has taught us a lot, pioneering immunosuppressive therapies, graft encapsulation, tissue engineering, and test of different implant sites and has stimulated a great variety of studies on β-cell function. This review starts from islet transplantation, presenting its current indications and the latest published trials, to arrive at the prospects of stem cell therapy, presenting the latest innovations in the field.

Total Pancreatectomy with Autologous Islet Cell Transplantation-The Current Indications

Total pancreatectomy is a major complex surgical procedure involving removal of the whole pancreatic parenchyma and duodenum. It leads to lifelong pancreatic exocrine and endocrine insufficiency. The control of surgery-induced diabetes (type 3) requires insulin therapy. Total pancreatectomy with autologous islet transplantation (TPAIT) is performed in order to prevent postoperative diabetes and its serious complications. It is very important whether it is safe and beneficial for patients in terms of postoperative morbidity and mortality, and long-term results including quality of life. Small duct painful chronic pancreatitis (CP) is a primary indication for TPAIT, but currently the indications for this procedure have been extended. They also include hereditary/genetic pancreatitis (HGP), as well as less frequent indications such as benign/borderline pancreatic tumors (intraductal papillary neoplasms, neuroendocrine neoplasms) and “high-risk pancreatic stump”. The use of TPAIT in malignant pancreatic and peripancreatic neoplasms has been reported in the worldwide literature but currently is not a standard but rather a controversial management in these patients. In this review, history, technique, indications, and contraindications, as well as short-term and long-term results of TPAIT, including pediatric patients, are described.

Efficacy and safety of islet autotransplantation after total pancreatectomy in chronic pancreatitis: A systematic review and meta-analysis including 17 studies

AIMS

Islet autotransplantation (IAT), in conjunction with total pancreatectomy (TP), is used to relieve pain in patients with chronic pancreatitis (CP), while reducing the incidence of brittle diabetes. We aimed to evaluate the efficacy and safety of IAT after TP (TPIAT) in this setting.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials since 1977. Data were extracted from published papers. Random-effects meta-analysis and meta-regression models were built to assess the outcomes and effect of different factors. Subgroup and sensitivity analyses were conducted to examine the between-study heterogeneity, which was assessed using Cochrane's Q and I² statistic.

RESULTS

A total of 17 studies, including 1024 patients, met the eligibility criteria. The median cohort size was 21 patients (range: 5-409). The pooled incidence rates of insulin independence, narcotic independence and mortality at last follow-up were 11.47 per 100 patient-years (95% CI: 6.79-21.60, I²=91.0%), 18.11 per 100 patient-years (95% CI: 5.29-62.04, I²=98.8%) and 2.88 per 100 patient-years (95% CI: 1.75-4.74, I²=46.8%), respectively. However, the heterogeneity level of our results was high, which was due to differences in research methods and definitions of outcomes between studies. Therefore, our results should be interpreted with caution.

CONCLUSIONS

TPIAT can effectively relieve pain and reduce the risk of surgical diabetes with no increase in mortality or morbidity. Prospective, randomized, clinical trials are required to further evaluate selection of patients and the timing of TPIAT.

Pilot study: deficiency of mannose-binding lectin-dependent lectin pathway, a novel modulator in outcome from pancreatic islet auto-transplantation

Background

Numerous factors influence pancreatic islet survival following auto-transplantation. Of these, the host immune response in the early peri-operative period is one of the most important. In this study we investigated the role of the mannose-binding lectin (MBL)-dependent pathway in a group of total pancreatectomy (TP) islet auto-transplantation (TPIAT) patients and classified them as competent or deficient in MBL activity. Complement pathway activities, MBL protein and inflammatory cytokine concentrations were evaluated from eleven pancreatic islet auto-transplant patients from two institutions.

Methods

Eleven patients from two institutions were prospectively recruited. Serum was screened at different time points for 29 different cytokines and compared according to their MBL deficient or competent status. Twelve patients from previous TPIAT patients also underwent screening of MBL pathway activity.

Results

A total nine of twenty three patients (39%) were MBL pathway deficient. MCP-1, IL-7 and IL-1a concentrations were significantly lower in the MBL deficient cohort compared to the normal MBL group (P=0.0237, 0.0001 and 0.0051 respectively). IL-6 and IL-8 concentrations were significantly raised in the normal MBL group. MBL functional activity was lower in insulin-independent group compared to the insulin-dependent group.

Conclusions

Complement activation is an important, possibly damaging response during intra-portal islet infusion. MBL pathway deficiency appears common in this population and the cytokine response was attenuated in MBL pathway deficient patients. Therapeutic MBL pathway blockade during and following islet auto-transplantation (IAT) may improve islet survival and function and thereby clinical outcome.

Modeling the Iatrogenic Pancreatic Cancer Risk After Islet Autotransplantation in Mouse

Iatrogenic pancreatic cancer metastasis after islet infusion is a potential risk of islet autotransplantation performed after pancreatectomy. To model this risk, islets and/or pancreatic exocrine clusters obtained from a genetically engineered mouse model for pancreatic ductal adenocarcinoma (the LSL-Kras^G12D/+ ;LSL-Trp53^R172H/+ ;Pdx-1-Cre, termed KPC mouse) were transplanted via the portal vein in syngeneic wild type (WT) severely diabetic recipients in the following treatment groups: group A (n = 11) received KPC exocrine clusters in volume equal to 250 islet equivalents (IEQs); group B (n = 12) received 250 WT IEQs mixed with KPC exocrine clusters (1:1 volume ratio); group C (n = 5) received 250 KPC IEQs, and group D (n = 7) received 250 WT IEQs. The incidence of hepatic metastasis was assessed by magnetic resonance imaging and histology over the 13 months of follow-up. Overall survival was not different in the four groups. No mice developed liver metastases during the follow-up. Two mice developed spontaneous tumors: a liver hepatocellular tumor in group A and a malignant lymphoma in group D. Islets and/or exocrine clusters obtained by KPC mouse, a model that develops pancreatic cancer with 100% penetrance, do not retain the same risk of tumor development when transplanted via the portal vein in a syngeneic diabetic recipient.

Salvage Islet Auto Transplantation After Relaparatomy

BACKGROUND

To assess feasibility, safety, and metabolic outcome of islet auto transplantation (IAT) in patients undergoing completion pancreatectomy because of sepsis or bleeding after pancreatic surgery.

METHODS

From November 2008 to October 2016, approximately 22 patients were candidates to salvage IAT during emergency relaparotomy because of postpancreatectomy sepsis (n = 11) or bleeding (n = 11). Feasibility, efficacy, and safety of salvage IAT were compared with those documented in a cohort of 36 patients who were candidate to simultaneous IAT during nonemergency preemptive completion pancreatectomy through the pancreaticoduodenectomy.

RESULTS

The percentage of candidates that received the infusion of islets was significantly lower in salvage IAT than simultaneous IAT (59.1% vs 88.9%, P = 0.008), mainly because of a higher rate of inadequate islet preparations. Even if microbial contamination of islet preparation was significantly higher in candidates to salvage IAT than in those to simultaneous IAT (78.9% vs 20%, P < 0.001), there was no evidence of a higher rate of complications related to the procedure. Median follow-up was 5.45 ± 0.52 years. Four (36%) of 11 patients reached insulin independence, 6 patients (56%) had partial graft function, and 1 patient (9%) had primary graft nonfunction. At the last follow-up visit, median fasting C-peptide was 0.43 (0.19-0.93) ng/mL; median insulin requirement was 0.38 (0.04-0.5) U/kg per day, and median HbA1c was 6.6% (5.9%-8.1%). Overall mortality, in-hospital mortality, metabolic outcome, graft survival, and insulin-free survival after salvage IAT were not different from those documented after simultaneous IAT.

CONCLUSIONS

Our data demonstrate the feasibility, efficacy, and safety of salvage IAT after relaparotomy.

Autologous Islet Transplantation in Patients Requiring Pancreatectomy: A Broader Spectrum of Indications Beyond Chronic Pancreatitis

Islet autotransplantation (IAT) is usually performed in patients undergoing pancreatic surgery for chronic pancreatitis. In the present series, IAT was offered also to patients undergoing pancreatic surgery for both nonmalignant and malignant diseases, having either completion pancreatectomy as treatment for severe pancreatic fistulas (n = 21) or extensive distal pancreatectomy for neoplasms of the pancreatic neck (n = 19) or pancreatoduodenectomy because of the high risk of pancreatic fistula (n = 32). Fifty-eight of 72 patients who were eligible to this broader spectrum of indication actually received IAT. There was no evidence of a higher-than-expected rate of major complications for pancreatectomy. Forty-five patients receiving IAT were still alive at the time of the last scheduled follow-up (1375 ± 365 days). Eighteen (95%) of 19 and 11 (28%) of 39 patients reached insulin independence after partial or total pancreatectomy, respectively. The metabolic results were dependent on the transplanted islet mass. Thirty-one of 58 patients had malignant diseases of the pancreas or periampullary region, and only three patients developed ex novo liver metastases after IAT (median follow-up 914 ± 382 days). Our data demonstrate the feasibility, efficacy, and safety of IAT for a broader spectrum of clinical indications beyond chronic pancreatitis.

Improved Insulin Secretion by Autologous Islet Transplantation, Compared to Oral Antidiabetic Agents, after Distal Pancreatectomy

In this study, the effects of autologous islet transplantation (ITx) were compared to those of oral antidiabetic drugs (OAD) after distal pancreatectomy (NCT01922492). We enrolled nondiabetic patients who underwent distal pancreatectomy for benign tumors. In the ITx group, islets were isolated from the normal part of the resected pancreas and implanted via the portal vein. Patients who did not receive ITx were regularly monitored and were enrolled in the OAD group if diabetes mellitus developed. The OAD group was treated with metformin with or without vildagliptin. Metabolic parameters were monitored for 12 months postoperatively. Nine patients in the ITx group and 10 in the OAD group were included in the analysis. After 12 months, hemoglobin A1c significantly increased by 5% of the baseline in each group. Area under the curve for blood glucose (AUCglucose) of the 75-g oral glucose tolerance test increased similarly in the immediate postoperative period in both groups but significantly reduced only in the ITx group thereafter. Insulinogenic index (INSindex) significantly decreased from 25.6 ± 18.9 to 4.7 ± 3.7 in the OAD group, while no significant change was observed in the ITx group (from 15.0 ± 4.5 to 11.0 ± 8.2). In the multiple regression analysis, ITx was an independent factor for changes in AUCglucose and INSindex. In addition, changes in INSindex in the ITx group after postoperative 6 months were associated with the efficacy of islet isolation, amount of grafts, and peak serum HMGB1 and VEGF levels after ITx. ITx was superior to OAD in maintaining insulin secretory capacity and glucose tolerance after distal pancreatectomy.

Chronic Pancreatitis and Diabetes Mellitus

OPINION STATEMENT

Patients with chronic pancreatitis should be screening at least annually for diabetes. Lifestyle modifications remain to be an important part of treatment for diabetic control. Unless contraindicated or not tolerated, metformin can be initiated and continued concurrently with other anti-diabetic agents or insulin. All anti-diabetic agents should be used based on their physiology and adverse effect profiles, along with the metabolic status of patients. Insulin therapy should be initiated without delay for any of the following: symptomatic or overt hyperglycemia, catabolic state secondary to uncontrolled diabetes, history of diabetic ketoacidosis, hospitalization or acute exacerbation of pancreatitis, or hyperglycemia that cannot be otherwise controlled. Dose adjustment should be done conservatively as these patients are more likely to be insulin sensitive and have loss of counter regulatory hormones. Insulin pump and continuous glucose monitoring should be considered early during therapy in selected patients. For patients undergoing total pancreatectomy or extensive partial pancreatectomy, evaluations to determine the eligibilities for islet cell autotransplantation should be considered.

Systematic review and meta-analysis of islet autotransplantation after total pancreatectomy in chronic pancreatitis patients

Islet autotransplantation (IAT) is a viable treatment for patients with severe chronic pancreatitis, this modality may prevent brittle diabetes mellitus after pancreatectomy. This systematic review and meta-analysis was performed to evaluated the outcomes of IAT after TP and discuss the factors that may affect the efficacy of this procedure. MEDLINE, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 1977 to 30 April 2014. Cohort Studies reported patients with IAT after TP were included. The studies and data were identified and extracted by two reviewers independently. Data were analyzed using STATA 12.0 and Comprehensive Meta AnalysisV2 software. Random effects model, meta-regression analysis, sensitivity analysis and publication bias were conducted to improve the comprehensive analysis. Twelve studies reporting the outcomes of 677 patients were included in this review. The insulin independent rate for IAT after TP at last follow-up was 3.72 per 100 person-years (95% CI: 1.00-6.44). The 30-day mortality was 2.1% (95% CI: 1.2-3.8%). The mortality at last follow-up was 1.09 per 100 person-years (95% CI: 0.21-1.97). Factors associated with incidence density of insulin independence in univariate meta-regression analyses included islet equivalents per kg body weight (IEQ/kgBW) (P=0.026). Our systematic review suggests that IAT is a safe modality for patients with CP need to undergo TP. A significant number of patients will achieve insulin independence for a long time after receiving enough IEQ/kgBW.

Autologous islet transplantation in patients requiring pancreatectomy for neoplasm

Autologous islet cell transplantation is a procedure performed to prevent or reduce the severity of diabetes after pancreatic resection. Autologous islet cell transplantation is being used almost exclusively in patients undergoing pancreatectomy because of painful, chronic pancreatitis, or multiple recurrent episodes of pancreatitis that is not controlled by standard medical and surgical treatments. Here, we discuss the possibility of extending the clinical indications for this treatment on the basis of our experience in patients undergoing pancreatic surgery for both nonmalignant and malignant diseases, including patients undergoing completion pancreatectomy because of anastomosis leakage after pancreaticoduodenectomy and those with pancreatic anastomosis deemed at high risk for failure.

Morbidity of total pancreatectomy with islet cell auto-transplantation compared to total pancreatectomy alone

BACKGROUND

In pancreatitis, total pancreatectomy (TP) is an effective treatment for refractory pain. Islet cell auto-transplantation (IAT) may mitigate resulting endocrinopathy. Short-term morbidity data for TP + IAT and comparisons with TP are limited.

METHODS

This study, using 2005-2011 National Surgical Quality Improvement Program data, examined patients with pancreatitis or benign neoplasms. Morbidity after TP alone was compared with that after TP + IAT.

RESULTS

In 126 patients (40%) undergoing TP and 191 (60%) patients undergoing TP + IAT, the most common diagnosis was chronic pancreatitis. Benign neoplasms were present in 46 (14%) patients, six of whom underwent TP + IAT. Patients in the TP + IAT group were younger and had fewer comorbidities than those in the TP group. Despite this, major morbidity was more frequent after TP + IAT than after TP [n = 79 (41%) versus n = 36 (29%); P = 0.020]. Transfusions were more common after TP + IAT [n = 39 (20%) versus n = 9 (7%); P = 0.001], as was longer hospitalization (13 days versus 9 days; P < 0.0001). There was no difference in mortality.

CONCLUSIONS

This study is the only comparative, multicentre study of TP and TP + IAT. The TP + IAT group experienced higher rates of major morbidity and transfusion, and longer hospitalizations. Better data on the longterm benefits of TP + IAT are needed. In the interim, this study should inform physicians and patients regarding the perioperative risks of TP + IAT.

Total pancreatectomy and islet autotransplantation in chronic pancreatitis: recommendations from PancreasFest

DESCRIPTION

Total pancreatectomy with islet autotransplantation (TPIAT) is a surgical procedure used to treat severe complications of chronic pancreatitis or very high risk of pancreatic cancer while reducing the risk of severe diabetes mellitus. However, clear guidance on indications, contraindications, evaluation, timing, and follow-up are lacking.

METHODS

A working group reviewed the medical, psychological, and surgical options and supporting literature related to TPIAT for a consensus meeting during PancreasFest.

RESULTS

Five major areas requiring clinical evaluation and management were addressed: These included: 1) indications for TPIAT; 2) contraindications for TPIAT; 3) optimal timing of the procedure; 4) need for a multi-disciplinary team and the roles of the members; 5) life-long management issues following TPIAP including diabetes monitoring and nutrition evaluation.

CONCLUSIONS

TPIAT is an effective method of managing the disabling complications of chronic pancreatitis and risk of pancreatic cancer in very high risk patients. Careful evaluation and long-term management of candidate patients by qualified multidisciplinary teams is required. Multiple recommendations for further research were also identified.

Autologous islet transplantation after total pancreatectomy for renal cell carcinoma metastases

Pancreatic metastases from renal cell carcinoma (RCC) may have a chronic and highly indolent course, and may be resected for cure after considerable delay following treatment of the primary tumor, in contrast to other more common pancreatic tumors. Surgical resection is the treatment of choice, which may lead to postpancreatectomy diabetes mellitus in the case of extensive resection. We present a 70-year-old patient with multifocal pancreatic metastases from RCC causing obstructive jaundice. A total pancreatectomy was required to excise two distant tumors in the head and tail of the pancreas, together with a segment VI liver resection. An autologous islet transplant (AIT) prepared from the central, uninvolved pancreas was carried out to prevent postpancreatectomy diabetes. The patient was rendered insulin-free and remains so with excellent glycemic control for 1 year of follow-up, and there is no evidence of tumor recurrence. The patient has been treated with adjuvant sunitinib to minimize risk of further recurrence. In conclusion, AIT after pancreatectomy may represent a useful option to treat patients with metastatic RCC. A critical component of this approach was dependent upon elaborate additional testing to exclude contamination of the islet preparation by cancerous cells.

Diabetes-free survival in patients who underwent islet autotransplantation after 50% to 60% distal partial pancreatectomy for benign pancreatic tumors

BACKGROUND

Several retrospective studies with short-term follow-up have demonstrated a low rate of new-onset diabetes after distal pancreatectomy for benign pancreatic tumors. We sought to determine the long-term diabetes-free survival of patients who underwent islet autotransplantation (IAT) after distal pancreatectomy and to identify any associations between the isolation parameters of autologous islets and diabetes-free survival.

METHODS

Among the 37 nondiabetic patients who underwent 50% to 60% partial pancreatectomy, 20 underwent IAT (IAT group; median follow-up period, 61 months). In the IAT group, diabetes-free survival was determined based on annual oral glucose tolerance tests, fasting blood glucose, and hemoglobin A1C.

RESULTS

The 7-year diabetes-free survival rate was 51% in the IAT group (median follow-up period, 61 months) and 45% in the 37 study subjects. Diabetes-free survival was significantly prolonged when islet yield per gram of pancreas weight was more than 5154 islet equivalents (IEQ)/g, even in patients with prediabetes and high insulin resistance who had a markedly high rate of diabetes development. The proportion of patients with impaired glucose tolerance at 2 years after distal pancreatectomy was 12 of 16 in the control group, 6 of 7 in patients with islet yields of less than 5154 IEQ/g, and 3 of 11 in patients with islet yields of more than 5154 IEQ/g (P=0.019).

CONCLUSIONS

Partial (50%-60%) pancreatectomy for benign pancreatic tumors had a major metabolic consequence, especially in patients with prediabetes and high insulin resistance. In this setting, prolonged diabetes-free survival was observed in patients who underwent IAT when a high islet yield per gram of pancreas was achieved.