α- or ß-Adrenergic blockade does not affect transplanted islet cell responses to hypoglycemia in type 1 diabetes.

Type 1 diabetes recipients of intrahepatic islet transplantation exhibit glucose-dependent suppression of insulin and activation of glucagon secretion in response to insulin-induced hypoglycemia associated with clinical protection from hypoglycemia. Whether sympathetic activation of adrenergic receptors on transplanted islets is required for these responses in defense against hypoglycemia is not known. To evaluate the adrenergic contribution to posttransplant glucose counterregulation, we performed a randomized, double-blind crossover study of responses during a hyperinsulinemic euglycemic-hypoglycemic clamp under phentolamine (α-adrenergic blockage), propranolol (ß-adrenergic blockage), or placebo infusion. Characteristics of participants (5 females/4 males) were as follows: median (range) age 53 (34-63) yr, diabetes duration 29 (18-56) yr, posttransplant 7.0 (1.9-8.4) yr, HbA1c 5.8 (4.5-6.8)%, insulin in-/dependent 5/4, all on tacrolimus-based immunosuppression. During the clamp, blood pressure was lower with phentolamine and heart rate was lower with propranolol versus placebo (P < 0.05). There was no difference in the suppression of endogenous insulin secretion (derived from C-peptide measurements) during the euglycemic or hypoglycemic phases, and although levels of glucagon were similar with phentolamine or propranolol vs. placebo, the increase in glucagon from eu- to hypoglycemia was greater with propranolol vs. placebo (P < 0.05). Pancreatic polypeptide was greater with phentolamine versus placebo during the euglycemic phase (P < 0.05), and free fatty acids were lower and the glucose infusion rate was higher with propranolol versus placebo during the hypoglycemic phase (P < 0.05 for both). These results indicate that neither physiological α- nor ß-adrenergic blockade attenuates transplanted islet responses to hypoglycemia, suggesting sympathetic reinnervation of the islet graft is not necessary for posttransplant glucose counterregulation.NEW & NOTEWORTHY Whether adrenergic input to islets is necessary for glucose homeostasis in humans is debated. Here, the adrenergic contribution to intrahepatically transplanted islet cell responses to hypoglycemia in individuals with type 1 diabetes was investigated through α- or ß-adrenergic receptor blockade during hyperinsulinemic euglycemic-hypoglycemic clamps. Neither α- nor ß-adrenergic blockage affected the suppression of endogenous insulin or activation of glucagon secretion, suggesting that sympathetic reinnervation of islet grafts is not required for posttransplant defense against hypoglycemia.

Peri-Transplant Inflammation and Long-Term Diabetes Outcomes Were Not Impacted by Either Etanercept or Alpha-1-Antitrypsin Treatment in Islet Autotransplant Recipients.

The instant blood-mediated inflammatory response (IBMIR) causes islet loss and compromises diabetes outcomes after total pancreatectomy with islet autotransplant (TPIAT). We previously reported a possible benefit of etanercept in maintaining insulin secretion 3 months post-TPIAT. Here, we report 2-year diabetes outcomes and peri-operative inflammatory profiles from a randomized trial of etanercept and alpha-1 antitrypsin (A1AT) in TPIAT. We randomized 43 TPIAT recipients to A1AT (90 mg/kg IV x6 doses, n = 13), etanercept (50 mg then 25 mg SQ x 5 doses, n = 14), or standard care (n = 16). Inflammatory cytokines, serum A1AT and unmethylated insulin DNA were drawn multiple times in the perioperative period. Islet function was assessed 2 years after TPIAT with mixed meal tolerance test, intravenous glucose tolerance test and glucose-potentiated arginine induced insulin secretion. Cytokines, especially IL-6, IL-8, IL-10, and MCP-1, were elevated during and after TPIAT. However, only TNFα differed significantly between groups, with highest levels in the etanercept group (p = 0.027). A1AT increased after IAT in all groups (p < 0.001), suggesting endogenous upregulation. Unmethylated insulin DNA ratios (a marker of islet loss) and 2 years islet function testing were similar in the three groups. To conclude, we found no sustained benefit from administering etanercept or A1AT in the perioperative period.

Factors associated with favourable 5 year outcomes in islet transplant alone recipients with type 1 diabetes complicated by severe hypoglycaemia in the Collaborative Islet Transplant Registry.

AIMS/HYPOTHESIS: Islet transplantation has been studied in small cohorts of recipients with type 1 diabetes complicated by severe hypoglycaemic events (SHEs). We determined factors associated with favourable outcomes in a large cohort of recipients reported to the Collaborative Islet Transplant Registry (CITR). METHODS: In 398 non-uraemic islet transplant alone (ITA) recipients with type 1 diabetes and SHEs, transplanted between 1999 and 2015 and with at least 1 year follow-up, we analysed specified favourable outcomes against each of all available characteristics of pancreas donors, islet grafts, recipients and immunosuppressive regimens, as well as immunosuppression and procedure-related serious adverse events (SAEs). RESULTS: Four factors were associated with the highest rates of favourable outcomes: recipient age ≥35 years; total infused islets ≥325,000 islet equivalents; induction immunosuppression with T cell depletion and/or TNF-α inhibition; and maintenance with both mechanistic target of rapamycin (mTOR) and calcineurin inhibitors. At 5 years after the last islet infusion, of the recipients meeting these four common favourable factors (4CFF; N=126), 95% were free of SHEs, 76% had HbA1c <53 mmol/mol (7.0%), 73% had HbA1c <53 mmol/mol (7.0%) and absence of SHEs, and 53% were insulin independent, significantly higher rates than in the remaining recipients (<4CFF; N=272). The incidence of procedural and immunosuppression-related SAEs per recipient that resulted in sequelae, disability or death was low in both the 4CFF (0.056 per person) and <4CFF (0.074 per person) groups. CONCLUSIONS/INTERPRETATION: In recipients with type 1 diabetes complicated by SHEs, islet transplantation meeting 4CFF protected 95% from SHEs at 5 years after the last islet infusion and exerted a large and significant benefit on glycaemic control, with an acceptable safety profile for this subgroup of type 1 diabetes.

A randomized controlled pilot trial of etanercept and alpha-1 antitrypsin to improve autologous islet engraftment.

BACKGROUND: In total pancreatectomy with islet auto-transplantation, successful diabetes outcomes are limited by islet loss from the instant blood mediated inflammatory response. We hypothesized that blockade of the inflammatory response with either etanercept or alpha-1-antitrypsin would improve islet function and insulin independence. METHODS: We randomized 43 participants to receive A1AT (90 mg/kg x 6 doses, n = 13), or etanercept (50 mg then 25 mg x 5 doses, n = 14), or standard care (n = 16), aiming to reduce detrimental effects of innate inflammation on early islet survival. Islet graft function was assessed using mixed meal tolerance testing, intravenous glucose tolerance testing, glucose-potentiated arginine-induced insulin secretion studies, HbA1c, and insulin dose 3 months and 1 year post-TPIAT. RESULTS: We observed the most robust acute insulin response (AIRglu) and acute C-peptide response to glucose (ACRglu) at 3 months after TPIAT in the etanercept-treated group (p ≤ 0.02), but no differences in other efficacy measures. The groups did not differ overall at 1 year but when adjusted by sex, there was a trend towards a sex-specific treatment effect in females (AIRglu p = 0.05, ACRglu p = 0.06), with insulin secretion measures highest in A1AT-treated females. CONCLUSION: Our randomized trial supports a potential role for etanercept in optimizing early islet engraftment but it is unclear whether this benefit is sustained. Further studies are needed to evaluate possible sex-specific responses to either treatment. CLINICAL TRIAL NOTATION: This study was performed under an Investigational New Drug Application (IND #119828) from the Food and Drug Administration and was registered on clinicaltrials.gov (NCT#02713997).

Clinically available immunosuppression averts rejection but not systemic inflammation after porcine islet xenotransplant in cynomolgus macaques.

A safe, efficacious, and clinically applicable immunosuppressive regimen is necessary for islet xenotransplantation to become a viable treatment option for diabetes. We performed intraportal transplants of wild-type adult porcine islets in 25 streptozotocin-diabetic cynomolgus monkeys. Islet engraftment was good in 21, partial in 3, and poor in 1 recipient. Median xenograft survival was 25 days with rapamycin and CTLA4Ig immunosuppression. Adding basiliximab induction and maintenance tacrolimus to the base regimen significantly extended median graft survival to 147 days (p < .0001), with three animals maintaining insulin-free xenograft survival for 265, 282, and 288 days. We demonstrate that this regimen suppresses non-Gal anti-pig antibody responses, circulating effector memory T cell expansion, effector function, and infiltration of the graft. However, a chronic systemic inflammatory state manifested in the majority of recipients with long-term graft survival indicated by increased neutrophil to lymphocyte ratio, IL-6, MCP-1, CD40, and CRP expression. This suggests that this immunosuppression regimen fails to regulate innate immunity and resulting inflammation is significantly associated with increased incidence and severity of adverse events making this regimen unacceptable for translation. Additional studies are needed to optimize a maintenance regimen for regulating the innate inflammatory response.

Metabolic measures before surgery and long-term diabetes outcomes in recipients of total pancreatectomy and islet autotransplantation.

In this single-center, retrospective cohort study, we aimed to elucidate simple metabolic markers or surrogate indices of ß-cell function that best predict long-term insulin independence and goal glycemic HbA1c control (HbA1c ≤ 6.5%) after total pancreatectomy with islet autotransplantation (TP-IAT). Patients who underwent TP-IAT (n = 371) were reviewed for metabolic measures before TP-IAT and for insulin independence and glycemic control at 1, 3, and 5 years after TP-IAT. Insulin independence and goal glycemic control were achieved in 33% and 68% at 1 year, respectively. Although the groups who were insulin independent and dependent overlap substantially on baseline measures, an individual who has abnormal glycemia (prediabetes HbA1c or fasting glucose) or estimated IEQs/kg < 2500 has a very high likelihood of remaining insulin dependent after surgery. In multivariate logistic regression modelling, metabolic measures correctly predicted insulin independence in about 70% of patients at 1, 3, and 5 years after TP-IAT. In conclusion, metabolic testing measures before surgery are highly associated with diabetes outcomes after TP-IAT at a population level and correctly predict outcomes in approximately two out of three patients. These findings may aid in prognostic counseling for chronic pancreatitis patients who are likely to eventually need TP-IAT.

Progress in individualizing autologous islet isolation techniques for pediatric islet autotransplantation after total pancreatectomy in children for chronic pancreatitis.

Total pancreatectomy with islet autotransplantation is performed to treat chronic pancreatitis in children. Successful islet isolation must address the challenges of severe pancreatic fibrosis and young donor age. We have progressively introduced modifications to optimize enzymatic and mechanical dissociation of the pancreas during islet isolation. We evaluated 2 islet isolation metrics in 138 children-digest islet equivalents per gram pancreas tissue (IEQ/g) and digest IEQ per kilogram body weight (IEQ/kg), using multiple regression to adjust for key disease and patient features. Islet yield at digest had an average 4569 (standard deviation 2949) islet equivalent (IEQ)/g and 4946 (4009) IEQ/kg, with 59.1% embedded in exocrine tissue. Cases with very low yield (<2000 IEQ/g or IEQ/kg) have decreased substantially over time, 6.8% and 9.1%, respectively, in the most recent tertile of time compared to 19.2% and 23.4% in the middle and 34.1% and 36.4% in the oldest tertile. IEQ/g and IEQ/kg adjusted for patient and disease factors improved in consistency and yield in the modern era. Minimal mechanical disruption during digestion, warm enzymatic digestion using enzyme collagenase:NP activity ratio < 10:1, coupled with extended distension and trimming time during islet isolation of younger and fibrotic pediatric pancreases, gave increased islet yield with improved patient outcomes.

Phase 3 trial of human islet-after-kidney transplantation in type 1 diabetes.

Allogeneic islet transplant offers a minimally invasive option for ß cell replacement in the treatment of type 1 diabetes (T1D). The CIT consortium trial of purified human pancreatic islets (PHPI) in patients with T1D after kidney transplant (CIT06), a National Institutes of Health-sponsored phase 3, prospective, open-label, single-arm pivotal trial of PHPI, was conducted in 24 patients with impaired awareness of hypoglycemia while receiving intensive insulin therapy. PHPI were manufactured using standardized processes. PHPI transplantation was effective with 62.5% of patients achieving the primary endpoint of freedom from severe hypoglycemic events and HbA1c  ≤ 6.5% or reduced by ≥ 1 percentage point at 1 year posttransplant. Median HbA1c declined from 8.1% before to 6.0% at 1 year and 6.3% at 2 and 3 years following transplant (P < .001 for all vs baseline), with related improvements in hypoglycemia awareness and glucose variability. The improved metabolic control was associated with better health-related and diabetes-related quality of life. The procedure was safe and kidney allograft function remained stable after 3 years. These results add to evidence establishing allogeneic islet transplant as a safe and effective treatment for patients with T1D and unstable glucose control despite intensive insulin treatment, supporting the indication for PHPI in the post-renal transplant setting.

3'UTR enhances hCD47 cell surface expression, self-signal function, and reduces ER stress in porcine fibroblasts.

INTRODUCTION: Macrophages contribute to xenograft rejection by direct cytotoxicity and by amplifying T cell-mediated immune responses. It has been shown that transgenic expression of hCD47 protects porcine cells from human macrophages by restoring the CD47-SIRPα self-recognition signal. It has also been reported that the long 3' untranslated region (3'UTR) of the hCD47 gene, which is missing from constructs previously used to make hCD47 transgenic pigs, is critical for efficient cell surface expression in human cells. The aim of this study was to investigate the impact of a modified form of the 3'UTR on the expression, localization, and function of hCD47 in transfected porcine cells. METHODS: hCD47 constructs with and without the modified 3'UTR were knocked into the GGTA1 locus in porcine fetal fibroblasts using CRISPR. Flow cytometry of the transfected cells was used to analyze hCD47 localization. Endoplasmic reticulum (ER), mitochondrial, and oxidative stress were examined by gene expression analysis and confocal microscopy. Phagocytosis of transfected cells by human macrophages was measured by flow cytometry, and stimulation of human/non-human (NHP) primate lymphocytes by the cells was examined using a PBMCs proliferation assay. RESULTS: Cells transfected with the construct lacking the 3'UTR (hCD47(3'UTR-)) exhibited predominantly intracellular expression of hCD47, and showed evidence of ER stress, dysregulated mitochondrial biogenesis, oxidative stress, and autophagy. Inclusion of the 3'UTR (hCD47(3'UTR+)) decreased intracellular expression of hCD47 by 36% and increased cell surface expression by 53%. This was associated with a significant reduction in cellular stress markers and a higher level of protection from phagocytosis by human macrophages. Furthermore, hCD47(3'UTR+) porcine cells stimulated significantly less proliferation of human/NHP T cells than hCD47(3'UTR-) cells. CONCLUSION: Our results suggest the potential benefits of using hCD47 constructs containing the 3'UTR to generate genetically engineered hCD47-expressing donor pigs.

Performance of modified Igls criteria to evaluate islet autograft function after total pancreatectomy with islet autotransplantation - a retrospective study.

The Igls criteria assess islet function after islet allotransplant, based on C-peptide, insulin use, hemoglobin A1c, and severe hypoglycemia. However, these criteria as currently defined cannot be applied to total pancreatectomy islet autotransplant (TPIAT) patients. We tested modified criteria for assessing islet function in a large cohort of TPIAT patients (n = 379). Metabolic outcomes were assessed. We assigned Auto-Igls class to each patient as able and evaluated the utility, validity, and perioperative risk factors of Auto-Igls at 1-year post-IAT. We tested the association of Auto-Igls with independent measures of islet graft function, specifically continuous glucose monitoring (CGM) data or acute C-peptide response to glucose (ACRglu) from intravenous glucose tolerance tests. An Auto-Igls class was assigned to 264 patients (69%). Among patients who could not be classified, most were missing exact insulin dose. Seventy-three percent of TPIAT recipients were classified as optimal or good at 1 year. The only significant predictor of Auto-Igls class was islet mass transplanted (P < 0.0001). Auto-Igls class was associated with percent time in range (70-140 mg/dl) on CGM (P = 0.02) and ACRglu (P < 0.0001). Modified Igls classification for IAT permits simple, comprehensive assessment of metabolic outcomes after TPIAT and is associated with other islet functional measures.

Rejection of xenogeneic porcine islets in humanized mice is characterized by graft-infiltrating Th17 cells and activated B cells.

Xenogeneic porcine islet transplantation is a promising potential therapy for type 1 diabetes (T1D). Understanding human immune responses against porcine islets is crucial for the design of optimal immunomodulatory regimens for effective control of xenogeneic rejection of porcine islets in humans. Humanized mice are a valuable tool for studying human immune responses and therefore present an attractive alternative to human subject research. Here, by using a pig-to-humanized mouse model of xenogeneic islet transplantation, we described the human immune response to transplanted porcine islets, a process characterized by dense islet xenograft infiltration of human CD45+ cells comprising activated human B cells, CD4+ CD44+ IL-17+ Th17 cells, and CD68+ macrophages. In addition, we tested an experimental immunomodulatory regimen in promoting long-term islet xenograft survival, a triple therapy consisting of donor splenocytes treated with ethylcarbodiimide (ECDI-SP), and peri-transplant rituximab and rapamycin. We observed that the triple therapy effectively inhibited graft infiltration of T and B cells as well as macrophages, promoted transitional B cells both in the periphery and in the islet xenografts, and provided a superior islet xenograft protection. Our study therefore indicates an advantage of donor ECDI-SP treatment in controlling human immune cells in promoting long-term islet xenograft survival.

Profiling natural serum antibodies of non-human primates with a carbohydrate antigen microarray.

BACKGROUND: Engineering of α-Galactosyltransferase gene-knockout pigs circumvented hyperacute rejection of pig organs after xenotransplantation in non-human primates. Overcoming this hurdle revealed the importance of non-α-Gal carbohydrate antigens in the immunobiology of acute humoral xenograft rejection. METHODS: This study analyzed serum from seven naïve cynomolgus monkeys (blood type O/B/AB = 3/2/2) for the intensity of natural IgM and IgG signals using carbohydrate antigen microarray, which included historically reported α-Gal and non-α-Gal carbohydrate antigens with various modifications. RESULTS: The median (range) of IgM and IgG signals were 12.71 (7.23-16.38) and 9.05 (7.23-15.90), respectively. The highest IgM and IgG signals with narrowest distribution were from mono- and disaccharides, followed by modified structures. Natural anti-α-Gal antibody signals were medium to high in IgM (11.2-15.9) and medium in IgG (8.5-11.6) spectra, and was highest with Lac core structure (Galα1-3Galß1-4Glc, iGb3) and lowest with LacNAc core structure (Galα1-3Galß1-4GlcNAc). Similar signal intensities (up to 15.8 in IgM and up to 11.8 in IgG) were observed for historically detected natural non-α-Gal antigens, which included Tn antigen, T antigen, GM2 glycolipid, and Sda antigen. The hierarchical clustering analysis revealed the presence of clusters of anti-A antibodies and was capable of distinguishing between the blood group B and AB non-human primates. CONCLUSIONS: The results presented here provide the most comprehensive evaluation of natural antibodies present in cynomolgus monkeys.

Epigenetic biomarkers indicate islet cell death in xenotransplantation.

BACKGROUND: Xenotransplantation of porcine islets has emerged in recent decades as a potential treatment for type 1 diabetes (T1D). Current methods of detection, indicative of successful engraftment, occur downstream of actual islet death. Epigenetic biomarkers can be detected in circulating cell-free DNA (cfDNA) to provide an earlier indication of graft dysfunction. AIMS: The present study identified a biomarker of islet death using differential methylation of the insulin gene, INS, originating from ß-cells in porcine islets. MATERIALS & METHODS: Pyrosequencing primers specific for porcine INS were designed to quantify hypomethylation along 12 cysteine-guanine dinucleotide (CpG) sites, including three sites in the cyclic adenosine monophosphate (cAMP) response element (CRE) binding protein 2 (CRE2) binding region of the 5' untranslated region (UTR) and nine sites within intron 2. RESULTS: PCR amplification of bisulfite-converted DNA combined with pyrosequencing data support the conclusion that hypomethylated porcine INS is specific to islet origin. CONCLUSION: Moreover, the results of this study indicate a highly specific epigenetic biomarker, capable of detecting a single islet, supporting the measurement of cfDNA as a biomarker for transplanted islet death. Defining the epigenetic characteristics of porcine-derived islets within cfDNA will be crucial to develop a better understanding of graft survival immunology for transplantation.

Combination of pancreas volume and HbA1c level predicts islet yield in patients undergoing total pancreatectomy and islet autotransplantation.

Islet yield is an important predictor of acceptable glucose control after total pancreatectomy with islet autotransplantation (TP-IAT). We assessed if pancreas volume calculated with preoperative MRI could assess islet yield and postoperative outcomes. We reviewed dynamic MRI studies from 154 adult TP-IAT patients (2009-2016), and associations between calculated volumes and digest islet equivalents (IEQs) were tested. In multivariate regression analysis, pancreas volume (P < .001) and preoperative HbA1c levels (P = .009) were independently associated with digest IEQs. The IEQ prediction formula was calculated according to each preoperative HbA1c level, (a) pancreas volume × 5800 for HbA1c ≥ 6.5, (b) pancreas volume × 10 000 for HbA1c ≥5.7/<6.5 and (iii) pancreas volume × 11 400 for HbA1c < 5.7. The formula was internally validated with 28 TP-IAT patients between 2017 and 2018 (r2  = .657 and r2  = .710 when restricted to 24 patients without prior pancreatectomy). An estimated IEQs/Body Weight (kg) ≥3700 predicted HbA1c ≤6.5 and insulin independence at 1 year after TP-IAT with 77% and 88% sensitivity and 55% and 43% specificity, respectively. The combination of pancreas volume and preoperative HbA1c levels may be useful to estimate islet yield. Estimated IEQs were reasonably sensitive to predict acceptable glucose control at 1 year.

In vitro characterization of neonatal, juvenile, and adult porcine islet oxygen demand, ß-cell function, and transcriptomes.

BACKGROUND: There is currently a shortage of human donor pancreata which limits the broad application of islet transplantation as a treatment for type 1 diabetes. Porcine islets have demonstrated potential as an alternative source, but a study evaluating islets from different donor ages under unified protocols has yet to be conducted. METHODS: Neonatal porcine islets (NPI; 1-3 days), juvenile porcine islets (JPI; 18-21 days), and adult porcine islets (API; 2+ years) were compared in vitro, including assessments of oxygen consumption rate, membrane integrity determined by FDA/PI staining, ß-cell proliferation, dynamic glucose-stimulated insulin secretion, and RNA sequencing. RESULTS: Oxygen consumption rate normalized to DNA was not significantly different between ages. Membrane integrity was age dependent, and API had the highest percentage of intact cells. API also had the highest glucose-stimulated insulin secretion response during a dynamic insulin secretion assay and had 50-fold higher total insulin content compared to NPI and JPI. NPI and JPI had similar glucose responsiveness, ß-cell percentage, and ß-cell proliferation rate. Transcriptome analysis was consistent with physiological assessments. API transcriptomes were enriched for cellular metabolic and insulin secretory pathways, while NPI exhibited higher expression of genes associated with proliferation. CONCLUSIONS: The oxygen demand, membrane integrity, ß-cell function and proliferation, and transcriptomes of islets from API, JPI, and NPI provide a comprehensive physiological comparison for future studies. These assessments will inform the optimal application of each age of porcine islet to expand the availability of islet transplantation.

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Chapter 6: patient selection for pilot clinical trials of islet xenotransplantation.

Patients in whom type 1 diabetes is complicated by impaired awareness of hypoglycemia and recurrent episodes of severe hypoglycemia are candidates for islet or pancreas transplantation if severe hypoglycemia persists after completion of a structured stepped care approach or a formalized medical optimization run-in period that provides access to hypoglycemia-specific education including behavioral therapies, insulin analogs, and diabetes technologies under the close supervision of a specialist hypoglycemia service. Patients with type 1 diabetes and end-stage renal failure who cannot meet clinically appropriate glycemic goals or continue to experience severe hypoglycemia after completion of a formalized medical optimization program under the guidance of an expert diabetes care team are candidates for islet or pancreas transplantation either simultaneously with or after a previous kidney transplant. Similarly, patients with type 2 diabetes and problematic hypoglycemia or renal failure who meet these criteria are considered candidates for islet replacement. Likewise, patients with pancreatectomy-induced diabetes in whom an islet autograft was not available or deemed inappropriate are candidates for islet or pancreas transplantation if extreme glycemic lability persists despite best medical therapy. To justify participation of these transplant candidates in early-phase trials of porcine islet cell products, lack of timely access to islet or pancreas allotransplantation due to allosensitization, high islet dose requirements, or other factors, or alternatively, a more favorable benefit-risk determination associated with the xenoislet than the alloislet or allopancreas transplant must be demonstrated. Additionally, in non-uremic xenoislet recipients, the risks associated with diabetes must be perceived to be more serious than the risks associated with the xenoislet product and the rejection prophylaxis, and in xenoislet recipients with renal failure, the xenoislet product and immunosuppression must not impact negatively on renal transplant outcomes. The most appropriate patient group for islet xenotransplantation trials will be defined by the specific characteristics of each investigational xenoislet product and related technologies applied for preventing rejection. Selecting recipients who are more likely to experience prolonged benefits associated with the islet xenograft will help these patients comply with lifelong monitoring and other public health measures.

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Executive summary.

The International Xenotransplantation Association has updated its original "Consensus Statement on Conditions for Undertaking Clinical Trials of Porcine Islet Products in Type 1 Diabetes," which was published in Xenotransplantation in 2009. This update is timely and important in light of scientific progress and changes in the regulatory framework pertinent to islet xenotransplantation. Except for the chapter on "informed consent," which has remained relevant in its 2009 version, all other chapters included in the initial consensus statement have been revised for inclusion in this update. These chapters will not provide complete revisions of the original chapters; rather, they restate the key points made in 2009, emphasize new and under-appreciated topics not fully addressed in 2009, suggest relevant revisions, and communicate opinions that complement the consensus opinion. Chapter 1 provides an update on national regulatory frameworks addressing xenotransplantation. Chapter 2 a, previously Chapter 2, suggests several important revisions regarding the generation of suitable source pigs from the perspective of the prevention of xenozoonoses. The newly added Chapter 2b discusses conditions for the use of genetically modified source pigs in clinical islet xenotransplantation. Chapter 3 reviews porcine islet product manufacturing and release testing. Chapter 4 revisits the critically important topic of preclinical efficacy and safety data required to justify a clinical trial. The main achievements in the field of transmission of all porcine microorganisms, the rationale for more proportionate recipient monitoring, and response plans are reviewed in Chapter 5. Patient selection criteria and circumstances where trials of islet xenotransplantation would be both medically and ethically justified are examined in Chapter 6 in the context of recent advances in available and emerging alternative therapies for serious and potentially life-threatening complications of diabetes. It is hoped that this first update of the International Xenotransplantation Association porcine islet transplant consensus statement will assist the islet xenotransplant scientific community, sponsors, regulators, and other stakeholders actively involved in the clinical translation of islet xenotransplantation.

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Chapter 3: Porcine islet product manufacturing and release testing criteria.

In the 2009 IXA consensus, the requirements for the quality and control of manufacturing of porcine islet products were based on the U.S. regulatory framework where the porcine islet products fall within the definition of somatic cell therapy under the statutory authority of the U.S. Food and Drug Administration (FDA). In addition, porcine islet products require pre-market approval as a biologic product under the Public Health Services Act and they meet the definition of a drug under the Federal Food, Drug, and Cosmetic Act (FD&C Act). Thus, they are subject to applicable provisions of the law and as such, control of manufacturing as well as reproducibility and consistency of porcine islet products, safety of porcine islet products, and characterization of porcine islet products must be met before proceeding to clinical trials. In terms of control of manufacturing as well as reproducibility and consistency of porcine islet products, the manufacturing facility must be in compliance with current Good Manufacturing Practices (cGMP) guidelines appropriate for the initiation of Phase 1/2 clinical trials. Sponsors intending to conduct a Phase 1/2 trial of islet xenotransplantation products must be able to demonstrate the safety of the product through the establishment of particular quality assurance and quality control procedures. All materials (including animal source and pancreas) used in the manufacturing process of the porcine islet products must be free of adventitious agents. The final porcine islet product must undergo tests for the presence of these adventitious agents including sterility, mycoplasma (if they are cultured), and endotoxin. Assessments of the final product must include the safety specifications mentioned above even if the results are not available until after release as these data would be useful for patient diagnosis and treatment if necessary. In addition, a plan of action must be in place for patient notification and treatment in case the sterility culture results are positive. In terms of the characterization of porcine islet products and product release criteria, the information on the porcine islet products should be acquired from a sample of the final product to be used for transplantation and must include the morphology of the islets, specific identity, purity, viability, and potency of the product. In addition, information on the quantity of the islet products should also be provided in a standardized fashion and this should be in terms of islet equivalents and/or cell numbers. The current consensus was created to provide guidelines that manufacturing facilities may find helpful in the manufacture of and the release criteria for porcine islet products including encapsulated islets and combined islet products. Our intent with the above recommendations is to provide a framework for individual porcine islet manufacturing facilities to ensure a high level of safety for the initiation of Phase 1/2 clinical trials on porcine islet xenotransplantation.

First update of the International Xenotransplantation Association consensus statement on conditions for undertaking clinical trials of porcine islet products in type 1 diabetes--Chapter 1: update on national regulatory frameworks pertinent to clinical islet xenotransplantation.

Islet xenotransplantation represents an attractive solution to overcome the shortage of human islets for use in type 1 diabetes. The wide-scale application of clinical islet xenotransplantation, however, requires that such a procedure takes place in a specifically and tightly regulated environment. With a view to promoting the safe application of clinical islet xenotransplantation, a few years ago the International Xenotransplantation Association (IXA) published a Consensus Statement that outlined the key ethical and regulatory requirements to be satisfied before the initiation of xenotransplantation studies in diabetic patients. This earlier IXA Statement also documented a disparate regulatory landscape among different geographical areas. This situation clearly fell short of the 2004 World Health Assembly Resolution WHA57.18 that urged Member States "to cooperate in the formulation of recommendations and guidelines to harmonize global practices" to ensure the highest ethical and regulatory standards on a global scale. In this new IXA report, IXA members who are active in xenotransplantation research in their respective geographic areas herewith briefly describe changes in the regulatory frameworks that have taken place in the intervening period in the various geographic areas or countries. The key reassuring take-home message of the present report is that many countries have embraced the encouragement of the WHO to harmonize the procedures in a more global scale. Indeed, important regulatory changes have taken place or are in progress in several geographic areas that include Europe, Korea, Japan, and China. Such significant regulatory changes encompass the most diverse facets of the clinical application of xenotransplantation and comprise ethical aspects, source animals and product specifications, study supervision, sample archiving, patient follow-up and even insurance coverage in some legislations. All these measures are expected to provide a better care and protection of recipients of xenotransplants but also a higher safety profile to xenotransplantation procedures with an ultimate net gain in terms of international public health.

Factors Predicting Outcomes After a Total Pancreatectomy and Islet Autotransplantation Lessons Learned From Over 500 Cases.

OBJECTIVE: Our objective was to analyze factors predicting outcomes after a total pancreatectomy and islet autotransplantation (TP-IAT). BACKGROUND: Chronic pancreatitis (CP) is increasingly treated by a TP-IAT. Postoperative outcomes are generally favorable, but a minority of patients fare poorly. METHODS: In our single-centered study, we analyzed the records of 581 patients with CP who underwent a TP-IAT. Endpoints included persistent postoperative "pancreatic pain" similar to preoperative levels, narcotic use for any reason, and islet graft failure at 1 year. RESULTS: In our patients, the duration (mean ±â€ŠSD) of CP before their TP-IAT was 7.1 ±â€Š0.3 years and narcotic usage of 3.3 ±â€Š0.2 years. Pediatric patients had better postoperative outcomes. Among adult patients, the odds of narcotic use at 1 year were increased by previous endoscopic retrograde cholangiopancreatography (ERCP) and stent placement, and a high number of previous stents (>3). Independent risk factors for pancreatic pain at 1 year were pancreas divisum, previous body mass index >30, and a high number of previous stents (>3). The strongest independent risk factor for islet graft failure was a low islet yield-in islet equivalents (IEQ)-per kilogram of body weight. We noted a strong dose-response relationship between the lowest-yield category (<2000 IEQ) and the highest (≥5000 IEQ or more). Islet graft failure was 25-fold more likely in the lowest-yield category. CONCLUSIONS: This article represents the largest study of factors predicting outcomes after a TP-IAT. Preoperatively, the patient subgroups we identified warrant further attention.