Total Pancreatectomy With Islet Autotransplantation as an Alternative to High-risk Pancreatojejunostomy After Pancreaticoduodenectomy: A Prospective Randomized Trial.

OBJECTIVE: To compare pancreaticoduodenectomy (PD) and total pancreatectomy (TP) with islet autotransplantation (IAT) in patients at high risk of postoperative pancreatic fistula (POPF). BACKGROUND: Criteria to predict the risk of POPF occurrence after PD are available. However, even when a high risk of POPF is predicted, TP is not currently accepted as an alternative to PD, because of its severe consequences on glycaemic control. Combining IAT with TP may mitigate such consequences. METHODS: Randomized, open-label, controlled, bicentric trial (NCT01346098). Candidates for PD at high-risk pancreatic anastomosis (ie, soft pancreas and duct diameter ≤3 mm) were randomly assigned (1:1) to undergo either PD or TP-IAT. The primary endpoint was the incidence of complications within 90 days after surgery. RESULTS: Between 2010 and 2019, 61 patients were assigned to PD (n=31) or TP-IAT (n=30). In the intention-to-treat analysis, morbidity rate was 90·3% after PD and 60% after TP-IAT ( P =0.008). According to complications' severity, PD was associated with an increased risk of grade ≥2 [odds ratio (OR)=7.64 (95% CI: 1.35-43.3), P =0.022], while the OR for grade ≥3 complications was 2.82 (95% CI: 0.86-9.24, P =0.086). After TP-IAT, the postoperative stay was shorter [median: 10.5 vs 16.0 days; P <0.001). No differences were observed in disease-free survival, site of recurrence, disease-specific survival, and overall survival. TP-IAT was associated with a higher risk of diabetes [hazard ratio=9.1 (95% CI: 3.76-21.9), P <0.0001], but most patients maintained good metabolic control and showed sustained C-peptide production over time. CONCLUSIONS: TP-IAT may become the standard treatment in candidates for PD, when a high risk of POPF is predicted.

Follicular helper T cell signature of replicative exhaustion, apoptosis, and senescence in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is the most frequent primary antibody deficiency whereby follicular helper T (Tfh) cells fail to establish productive responses with B cells in germinal centers. Here, we analyzed the frequency, phenotype, transcriptome, and function of circulating Tfh (cTfh) cells in CVID patients displaying autoimmunity as an additional phenotype. A group of patients showed a high frequency of cTfh1 cells and a prominent expression of PD-1 and ICOS as well as a cTfh mRNA signature consistent with highly activated, but exhausted, senescent, and apoptotic cells. Plasmatic CXCL13 levels were elevated in this group and positively correlated with cTfh1 cell frequency and PD-1 levels. Monoallelic variants in RTEL1, a telomere length- and DNA repair-related gene, were identified in four patients belonging to this group. Their blood lymphocytes showed shortened telomeres, while their cTfh were more prone to apoptosis. These data point toward a novel pathogenetic mechanism in CVID, whereby alterations in DNA repair and telomere elongation might predispose to antibody deficiency. A Th1, highly activated but exhausted and apoptotic cTfh phenotype was associated with this form of CVID.

The hepatokine fetuin-A disrupts functional maturation of pancreatic beta cells.

AIMS/HYPOTHESIS: Neonatal beta cells carry out a programme of postnatal functional maturation to achieve full glucose responsiveness. A partial loss of the mature phenotype of adult beta cells may contribute to a reduction of functional beta cell mass and accelerate the onset of type 2 diabetes. We previously found that fetuin-A, a hepatokine increasingly secreted by the fatty liver and a determinant of type 2 diabetes, inhibits glucose-stimulated insulin secretion (GSIS) of human islets. Since fetuin-A is a ubiquitous fetal glycoprotein that declines peripartum, we examined here whether fetuin-A interferes with the functional maturity of beta cells. METHODS: The effects of fetuin-A were assessed during in vitro maturation of porcine neonatal islet cell clusters (NICCs) and in adult human islets. Expression alterations were examined via microarray, RNA sequencing and reverse transcription quantitative real-time PCR (qRT-PCR), proteins were analysed by western blotting and immunostaining, and insulin secretion was quantified in static incubations. RESULTS: NICC maturation was accompanied by the gain of glucose-responsive insulin secretion (twofold stimulation), backed up by mRNA upregulation of genes governing beta cell identity and function, such as NEUROD1, UCN3, ABCC8 and CASR (Log2 fold change [Log2FC] > 1.6). An active TGFß receptor (TGFBR)-SMAD2/3 pathway facilitates NICC maturation, since the TGFBR inhibitor SB431542 counteracted the upregulation of aforementioned genes and de-repressed ALDOB, a gene disallowed in mature beta cells. In fetuin-A-treated NICCs, upregulation of beta cell markers and the onset of glucose responsiveness were suppressed. Concomitantly, SMAD2/3 phosphorylation was inhibited. Transcriptome analysis confirmed inhibitory effects of fetuin-A and SB431542 on TGFß-1- and SMAD2/3-regulated transcription. However, contrary to SB431542 and regardless of cMYC upregulation, fetuin-A inhibited beta cell proliferation (0.27 ± 0.08% vs 1.0 ± 0.1% Ki67-positive cells in control NICCs). This effect was sustained by reduced expression (Log2FC ≤ -2.4) of FOXM1, CENPA, CDK1 or TOP2A. In agreement, the number of insulin-positive cells was lower in fetuin-A-treated NICCs than in control NICCs (14.4 ± 1.2% and 22.3 ± 1.1%, respectively). In adult human islets fetuin-A abolished glucose responsiveness, i.e. 1.7- and 1.1-fold change over 2.8 mmol/l glucose in control- and fetuin-A-cultured islets, respectively. In addition, fetuin-A reduced SMAD2/3 phosphorylation and suppressed expression of proliferative genes. Of note, in non-diabetic humans, plasma fetuin-A was negatively correlated (p = 0.013) with islet beta cell area. CONCLUSIONS/INTERPRETATION: Our results suggest that the perinatal decline of fetuin-A relieves TGFBR signalling in islets, a process that facilitates functional maturation of neonatal beta cells. Functional maturity remains revocable in later life, and the occurrence of a metabolically unhealthy milieu, such as liver steatosis and elevated plasma fetuin-A, can impair both function and adaptive proliferation of beta cells. DATA AVAILABILITY: The RNAseq datasets and computer code produced in this study are available in the Gene Expression Omnibus (GEO): GSE144950; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE144950.

Transcriptional dynamics of induced pluripotent stem cell differentiation into ß cells reveals full endodermal commitment and homology with human islets.

BACKGROUND AIMS: Induced pluripotent stem cells (iPSCs) have the capacity to generate ß cells in vitro, but the differentiation is incomplete and generates a variable percentage of off-target cells. Single-cell RNA sequencing offers the possibility of characterizing the transcriptional dynamics throughout differentiation and determining the identity of the final differentiation product. METHODS: Single-cell transcriptomics data were obtained from four stages across differentiation of iPSCs into ß cells and from human donor islets. RESULTS: Clustering analysis revealed that iPSCs undertake a full endoderm commitment, and the obtained endocrine pancreatic cells have high homology with mature islets. The iPSC-derived ß cells were devoid of pluripotent residual cells, and the differentiation was pancreas-specific, as it did not generate ectodermal or mesodermal cells. Pseudotime trajectory identified a dichotomic endocrine/non-endocrine cell fate and distinct subgroups in the endocrine branch. CONCLUSIONS: Future efforts to produce ß cells from iPSCs must aim not only to improve the resulting endocrine cell but also to avoid differentiation into non-pancreatic endoderm cells.

Reduced PD-1 expression on circulating follicular and conventional FOXP3+ Treg cells in children with new onset type 1 diabetes and autoantibody-positive at-risk children.

Autoantibodies (AAbs) are a hallmark of Type 1 diabetes (T1D). Alterations in the frequency and phenotype of follicular helper (Tfh) T cells have been previously documented in patients with type 1 diabetes (T1D), but the contribution of follicular regulatory T (Treg) cells, which are responsible for suppressing AAb development, is less clear. Here, we investigated the frequency and activation status of follicular (CXCR5+) and conventional (CXCR5-) Treg cells in the blood of children with new-onset T1D, and children with risk for developing T1D (AAb-positive) and compared them to AAb-negative controls. Blood follicular and conventional Treg cells were higher in frequency in children with new onset T1D, but expressed reduced amounts of PD-1 as compared to AAb-negative children. Interestingly, the proportion of circulating FOXP3+ Tregs expressing PD-1 was also reduced in AAb-positive at-risk children as compared to AAb-negative controls, suggesting its potential use as a biomarker of disease progression. Follicular Treg cells were reduced in frequency in the spleens of prediabetic NOD mice as they became older and turned diabetic. Interestingly, PD-1 expression declined also on circulating follicular and conventional Treg cells in prediabetic NOD mice as they aged. Together, these findings show that the frequency of circulating follicular and conventional Treg cells and their levels of PD-1 change with disease progression in children at-risk for developing T1D and in NOD mice.

The role of Cox-2 and prostaglandin E2 receptor EP3 in pancreatic ß-cell death.

Elevated levels of lipids, in particular saturated fatty acids, are known to be associated with type 2 diabetes (T2D) and to have a negative effect on ß-cell function and survival. We bring new evidence indicating that palmitate up-regulates cyclooxygenase-2 (COX-2) expression levels in human islets and in MIN6 ß cells, and that it is elevated in islets isolated from T2D donors. Both small interfering specific cyclooxygenase-2 small interfering RNA (siRNA) or the COX-2 inhibitor celecoxib significantly inhibited apoptosis induced by palmitate. Prostaglandin E2 (PGE2), the predominant product of COX-2 enzymatic activity, activates membrane receptors, which are members of the GPCR-family (EP1-EP4). In the present study, elevated expression of the PGE2 receptor subtype 3 (EP3) receptor was observed in ß cells exposed to palmitate and in islets from individuals with T2D. Down-regulation of the pathway using EP3 siRNA or the specific L-798,106 antagonist markedly decreased the levels of palmitate-induced apoptosis. Altogether, our data put forward the COX-2-PGE2-EP3 pathway as one of the mediators of palmitate-induced apoptosis in ß-cells.-Amior, L., Srivastava, R., Nano, R., Bertuzzi, F., Melloul, D. The role of Cox-2 and prostaglandin E2 receptor EP3 in pancreatic ß-cell death.

Diabetes-free survival after extended distal pancreatectomy and islet auto transplantation for benign or borderline/malignant lesions of the pancreas.

Islet autotransplant is particularly attractive to prevent diabetes after extended pancreatectomy for benign or borderline/malignant pancreas disease. Between 2008 and 2018, 25 patients underwent left extended pancreatectomy (>60%) and islet autotransplant for a neoplasm located in the pancreatic neck or proximal body. Overall, disease-free and diabetes-free survivals were estimated and compared with those observed in 68 nondiabetic patients who underwent distal pancreatectomy for pancreatic neoplasms without islet autotransplant. Median follow-up was 4 years. We observed no deaths and a low morbidity (nonserious procedure-related complications in 2 of 25 patients). Patient and insulin-independent survival rates at 4 years were 100% and 96%, respectively. Glucose homeostasis remained within a nondiabetic range at all times for 19 (73%) of 25 patients. Preoperative glycemic level and insulin resistance were major predictors of diabetes development in these patients. Patients undergoing islet autotransplant had a longer diabetes-free survival than did patients without islet autotransplant (P = .04). In conclusion, islet autotransplant after extended pancreatic resection for neoplasms is a safe and successful procedure for preventing diabetes.

Establishment, characterization and long-term culture of human endocrine pancreas-derived microvascular endothelial cells.

BACKGROUND: In vitro primary cultures of microvascular endothelial cells from endocrine pancreas are difficult to obtain, but can be a very helpful tool for studies of islet biology, transplantation and regenerative medicine. METHODS: We applied a protocol recently described for the isolation and culture of brain microvascular endothelial cells (EC) on human pancreatic islets. EC obtained were characterized in terms of morphological (light and transmission electron microscopy), phenotypical (by immunofluorescence and flow cytometry) and functional (cord formation assay and protein secretion by multiplex bead-based assay) characteristics. RESULTS: EC were obtained from 25% of islet preparations processed. Two primary endothelial cell lines showed high proliferative potential and were deeply characterized: they presented endothelial cell morphology and expressed CD31, CD49a, CD49e, CD34, von Willebrand Factor (vWF), Vascular Endothelial CAdherin (VE-CAD), Tyrosine Kinase with Ig and EGF Homology Domains-2 (TIE2), Vascular Endothelial Growth Factor Receptor 1 (VEGFR1), Ulex lectin and the endothelium endocrine-specific marker nephrin. Besides, they were able to form cordons in vitro and secreted factors involved in the process of angiogenesis such as Vascular Endothelial Growth Factor (VEGF), Monocyte Chemotactic Protein 1 (MCP-1), interleukin (IL)-8 and Melanoma Growth Stimulatory Activity Alpha (GROα). These cell lines were termed Human Islet Microvascular Endothelial Cells (HIMEC). DISCUSSION: This study establishes a simple and effective strategy for isolation and long-term culture of EC derived from human pancreatic islet. HIMEC in culture preserve phenotype and functional properties and are, therefore, a useful tool for future experiments of in vitro pancreas modelling, co-transplantation with pancreatic islets, re-vascularization of scaffold or matrix for regenerative medicine purposes.

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.

Relaparotomy for a pancreatic fistula after a pancreaticoduodenectomy: a comparison of different surgical strategies.

INTRODUCTION: A relaparotomy for a pancreatic fistula (PF) after a pancreaticoduodenectomy (PD) is a formidable operation, and the appropriate treatment of anastomotic leakage is under debate. The objective of this study was to compare the outcomes of different strategies in managing the pancreatic remnant during a relaparotomy for PF after a PD. METHODS: In this retrospective study on prospectively collected data, 669 PD were performed between 2004 and 2011. The study group comprised 31 patients requiring a relaparotomy, because of delayed haemorrhage (n = 19) or sepsis (n = 12). The pancreatic stump was treated either using pancreas-preserving techniques (simple drainage or duct occlusion) or completion of a pancreatectomy (CP). In 2008, autologous islet transplantation (AIT) was introduced for endocrine tissue rescue of CP. RESULTS: The mortality rate, blood loss and transfusion requirement were similar for all techniques. Patients undergoing a CP required a further relaparotomy less frequently than patients with pancreas preservation (7% versus 59%, P < 0.01), and the intensive care unit (ICU) stay was reduced after CP (P = 0.058). PF persisted at discharge in 66% of patients after pancreas-preserving techniques. AIT was associated with CP in 7 patients, of whom one died post-operatively. Long-term graft function was maintained in four out of six surviving patients, with one insulin-independent patient at 36 months after transplantation. CONCLUSIONS: When a PF requires a relaparotomy, CP has become our favoured technique. AIT can reduce the metabolic impact of the procedure.

Evaluation of the effects of canning variables on the mineral composition of canned cowpeas (Vigna unguiculata l. Walp) using multi-response analysis.

This study aims to investigate the effects of canning variables (cooking time, storage time, volume of vinegar, salt and sugar) on the mineral composition of canned cowpea (Vigna unguiculata (L.) Walp) and which conditions provide optimised preservation of the mineral content of the grains. Different formulations of canned cowpeas were produced following two levels factorial experimental design using five variables. A set of 11 different formulations were evaluated using the desirability function with essential minerals (Ca, Cu, Fe, Mn, Mg, P and Zn) as the response. The optimal multi-response conditions for higher mineral retention were: 360 days of storage at 30 ± 5 °C (ST2), 30 ml of vinegar, 9.0 g of NaCl, 18 min of cooking time, and 9.0 g, 19.5 g or 30 g of sugar (the effect of the sugar content at the evaluated range was not significant at 95% confidence level).

Autologous Pancreatic Islet Cell Transplantation Following Pancreatectomy for Pancreas Diseases Other Than Chronic Pancreatitis: A 15-Y Study of the Milan Protocol.

BACKGROUND: Pancreatogenic diabetes, a consequence of pancreatic tissue loss following pancreatectomy, poses a significant challenge for patients undergoing pancreatic surgery. Islet autotransplantation (IAT) offers a promising approach to prevent or alleviate pancreatogenic diabetes, but its application has been limited to individuals with painful chronic pancreatitis. METHODS: This study presents a 15-y clinical experience with the Milan Protocol, which expands IAT after pancreatectomy to a broader spectrum of patients with malignant and nonmalignant pancreatic diseases. The analysis evaluates feasibility, efficacy, and safety of IAT. Modified Igls criteria validated through the arginine test and mixed meal tolerance tests were used to assess long-term metabolic outcomes. RESULTS: Between November 2008 and June 2023, IAT procedures were performed on 114 of 147 candidates. IAT-related complications occurred in 19 of 114 patients (16.7%), with 5 being potentially serious. Patients exhibited sustained C-peptide secretion over the 10-y follow-up period, demonstrating a prevalence of optimal and good beta-cell function. Individuals who underwent partial pancreatectomy demonstrated superior metabolic outcomes, including sustained C-peptide secretion and a reduced risk of developing diabetes or insulin dependence compared with those who underwent total pancreatectomy. For patients who had total pancreatectomy, the quantity of infused islets and tissue volume were identified as critical factors influencing metabolic outcomes. An increased risk of recurrence or progression of baseline diseases was not observed in subjects with neoplasms. CONCLUSIONS: These findings provide valuable insights into the benefits and applications of IAT as a therapeutic option for pancreatogenic diabetes after pancreatic surgery, expanding its potential beyond painful chronic pancreatitis.

LDHB contributes to the regulation of lactate levels and basal insulin secretion in human pancreatic ß cells.

Using 13C6 glucose labeling coupled to gas chromatography-mass spectrometry and 2D 1H-13C heteronuclear single quantum coherence NMR spectroscopy, we have obtained a comparative high-resolution map of glucose fate underpinning ß cell function. In both mouse and human islets, the contribution of glucose to the tricarboxylic acid (TCA) cycle is similar. Pyruvate fueling of the TCA cycle is primarily mediated by the activity of pyruvate dehydrogenase, with lower flux through pyruvate carboxylase. While the conversion of pyruvate to lactate by lactate dehydrogenase (LDH) can be detected in islets of both species, lactate accumulation is 6-fold higher in human islets. Human islets express LDH, with low-moderate LDHA expression and ß cell-specific LDHB expression. LDHB inhibition amplifies LDHA-dependent lactate generation in mouse and human ß cells and increases basal insulin release. Lastly, cis-instrument Mendelian randomization shows that low LDHB expression levels correlate with elevated fasting insulin in humans. Thus, LDHB limits lactate generation in ß cells to maintain appropriate insulin release.

Rapamycin unbalances the polarization of human macrophages to M1.

Plasticity is a hallmark of macrophages, and in response to environmental signals these cells undergo different forms of polarized activation, the extremes of which are called classic (M1) and alternative (M2). Rapamycin (RAPA) is crucial for survival and functions of myeloid phagocytes, but its effects on macrophage polarization are not yet studied. To address this issue, human macrophages obtained from six normal blood donors were polarized to M1 or M2 in vitro by lipopolysaccharide plus interferon-γ or interleukin-4 (IL-4), respectively. The presence of RAPA (10 ng/ml) induced macrophage apoptosis in M2 but not in M1. Beyond the impact on survival in M2, RAPA reduced CXCR4, CD206 and CD209 expression and stem cell growth factor-ß, CCL18 and CCL13 release. In contrast, in M1 RAPA increased CD86 and CCR7 expression and IL-6, tumour necrosis factor-α and IL-1ß release but reduced CD206 and CD209 expression and IL-10, vascular endothelial growth factor and CCL18 release. In view of the in vitro data, we examined the in vivo effect of RAPA monotherapy (0·1 mg/kg/day) in 12 patients who were treated for at least 1 month before islet transplant. Cytokine release by Toll-like receptor 4-stimulated peripheral blood mononuclear cells showed a clear shift to an M1-like profile. Moreover, macrophage polarization 21 days after treatment showed a significant quantitative shift to M1. These results suggest a role of mammalian target of rapamycin (mTOR) into the molecular mechanisms of macrophage polarization and propose new therapeutic strategies for human M2-related diseases through mTOR inhibitor treatment.

Extending indications for islet autotransplantation in pancreatic surgery.

OBJECTIVE: To assess metabolic and oncologic outcomes of islet autotransplantation (IAT) in patients undergoing pancreatic surgery for either benign or malignant disease. BACKGROUND: IAT is performed to improve glycemic control after extended pancreatectomy, almost exclusively in patients with chronic pancreatitis. Limited experience is available for other indications or in patients with pancreatic malignancy. METHODS: In addition to chronic pancreatitis, indications for IAT were grade C pancreatic fistula (treated with completion or left pancreatectomy, as indicated); total pancreatectomy as an alternative to high-risk anastomosis during pancreaticoduodenectomy; and distal pancreatectomy for benign/borderline neoplasm of pancreatic body-neck. Malignancy was not an exclusion criterion. Metabolic and oncologic follow-up is presented. RESULTS: From November 2008 to June 2012, 41 patients were candidates to IAT (accounting for 7.5% of all pancreatic resections). Seven of 41 did not receive transplantation for inadequate islet mass (4 pts), patient instability (2 pts), or contamination of islet culture (1 pt). IAT-related complications occurred in 8 pts (23.5%): 4 bleeding, 3 portal thromboses (1 complete, 2 partial), and 1 sepsis. Median follow-up was 546 days. Fifteen of 34 patients (44%) reached insulin independence, 16 patients (47%) had partial graft function, 2 patients (6%) had primary graft nonfunction, and 1 patient (3%) had early graft loss. Seventeen IAT recipients had malignancy (pancreatic or periampullary adenocarcinoma in 14). Two of them had already liver metastases at surgery, 13 were disease-free at last follow-up, and none of 2 patients with tumor recurrence developed metastases in the transplantation site. CONCLUSIONS: Although larger data are needed to definitely exclude the risk of disease dissemination, the present study suggests that IAT indications can be extended to selected patients with neoplasm.

Allo Beta Cell transplantation: specific features, unanswered questions, and immunological challenge.

Type 1 diabetes (T1D) presents a persistent medical challenge, demanding innovative strategies for sustained glycemic control and enhanced patient well-being. Beta cells are specialized cells in the pancreas that produce insulin, a hormone that regulates blood sugar levels. When beta cells are damaged or destroyed, insulin production decreases, which leads to T1D. Allo Beta Cell Transplantation has emerged as a promising therapeutic avenue, with the goal of reinstating glucose regulation and insulin production in T1D patients. However, the path to success in this approach is fraught with complex immunological hurdles that demand rigorous exploration and resolution for enduring therapeutic efficacy. This exploration focuses on the distinct immunological characteristics inherent to Allo Beta Cell Transplantation. An understanding of these unique challenges is pivotal for the development of effective therapeutic interventions. The critical role of glucose regulation and insulin in immune activation is emphasized, with an emphasis on the intricate interplay between beta cells and immune cells. The transplantation site, particularly the liver, is examined in depth, highlighting its relevance in the context of complex immunological issues. Scrutiny extends to recipient and donor matching, including the utilization of multiple islet donors, while also considering the potential risk of autoimmune recurrence. Moreover, unanswered questions and persistent gaps in knowledge within the field are identified. These include the absence of robust evidence supporting immunosuppression treatments, the need for reliable methods to assess rejection and treatment protocols, the lack of validated biomarkers for monitoring beta cell loss, and the imperative need for improved beta cell imaging techniques. In addition, attention is drawn to emerging directions and transformative strategies in the field. This encompasses alternative immunosuppressive regimens and calcineurin-free immunoprotocols, as well as a reevaluation of induction therapy and recipient preconditioning methods. Innovative approaches targeting autoimmune recurrence, such as CAR Tregs and TCR Tregs, are explored, along with the potential of stem stealth cells, tissue engineering, and encapsulation to overcome the risk of graft rejection. In summary, this review provides a comprehensive overview of the inherent immunological obstacles associated with Allo Beta Cell Transplantation. It offers valuable insights into emerging strategies and directions that hold great promise for advancing the field and ultimately improving outcomes for individuals living with diabetes.

No Evidence of Long-Term Disruption of Glycometabolic Control After SARS-CoV-2 Infection.

PURPOSE: To assess whether dysglycemia diagnosed during severe acute respiratory syndrome coronavirus 2 pneumonia may become a potential public health problem after resolution of the infection. In an adult cohort with suspected coronavirus disease 2019 (COVID-19) pneumonia, we integrated glucose data upon hospital admission with fasting blood glucose (FBG) in the year prior to COVID-19 and during postdischarge follow-up. METHODS: From February 25 to May 15, 2020, 660 adults with suspected COVID-19 pneumonia were admitted to the San Raffaele Hospital (Milan, Italy). Through structured interviews/ medical record reviews, we collected demographics, clinical features, and laboratory tests upon admission and additional data during hospitalization or after discharge and in the previous year. Upon admission, we classified participants according to American Diabetes Association criteria as having (1) preexisting diabetes, (2) newly diagnosed diabetes, (3) hyperglycemia not in the diabetes range, or (4) normoglycemia. FBG prior to admission and during follow-up were classified as normal or impaired fasting glucose and fasting glucose in the diabetes range. RESULTS: In patients with confirmed COVID (n = 589), the proportion with preexisting or newly diagnosed diabetes, hyperglycemia not in the diabetes range and normoglycemia was 19.6%, 6.7%, 43.7%, and 30.0%, respectively. Patients with dysglycemia associated to COVID-19 had increased markers of inflammation and organs' injury and poorer clinical outcome compared to those with normoglycemia. After the infection resolved, the prevalence of dysglycemia reverted to preadmission frequency. CONCLUSIONS: COVID-19-associated dysglycemia is unlikely to become a lasting public health problem. Alarmist claims on the diabetes risk after COVID-19 pneumonia should be interpreted with caution.

Mesenchymal cells appearing in pancreatic tissue culture are bone marrow-derived stem cells with the capacity to improve transplanted islet function.

Adherent fibroblast-like cells have been reported to appear in cultures of human endocrine or exocrine pancreatic tissue during attempts to differentiate human beta cells from pancreatic precursors. A thorough characterization of these mesenchymal cells has not yet been completed, and there are no conclusive data about their origin.We demonstrated that the human mesenchymal cells outgrowing from cultured human pancreatic endocrine or exocrine tissue are pancreatic mesenchymal stem cells (pMSC) that propagate from contaminating pMSC. The origin of pMSC is partly extrapancreatic both in humans and mice, and by using green fluorescent protein (GFP(+)) bone marrow transplantation in the mouse model, we were able to demonstrate that these cells derive from the CD45(+) component of bone marrow. The pMSC express negligible levels of islet-specific genes both in basal conditions and after serum deprivation or exogenous growth factor exposure, and might not represent optimal candidates for generation of physiologically competent beta-cells. On the other hand, when cotransplanted with a minimal pancreatic islet mass, pMSC facilitate the restoration of normoglycemia and the neovascularization of the graft. These results suggest that pMSCs could exert an indirect role of "helper" cells in tissue repair processes.

Total pancreatectomy sequelae and quality of life: results of islet autotransplantation as a possible mitigation strategy.

Total pancreatectomy (TP) is a procedure weighed down not only by postoperative morbidity and mortality but also by long-term effects as a consequence of endocrine and exocrine pancreatic insufficiency. While the latter is now managed quite effectively with pancreatic enzyme replacement therapy, the former remains a challenge. The diabetes resulting after TP, with the complete loss of endogenous insulin and contraregulatory hormones, is characterized by important glycemic variations and is, therefore, frequently referred to as "brittle diabetes". One method to reduce the impact of brittle diabetes in patients undergoing TP is the re-infusion of autologous pancreatic islets isolated from the resected pancreas. Indications to islet autotransplantation (IAT), originally described for patients undergoing TP for chronic pancreatitis, have since been extended to selected patients with other benign and malignant diseases of pancreas. This review recaps on the literature regarding long-term postoperative complications, their impact on quality of life after TP and the role of IAT.

Generation of ß Cells from iPSC of a MODY8 Patient with a Novel Mutation in the Carboxyl Ester Lipase (CEL) Gene.

CONTEXT: Maturity-onset diabetes of the young (MODY) 8 is a rare form of monogenic diabetes characterized by a mutation in CEL (carboxyl ester lipase) gene, which leads to exocrine pancreas dysfunction, followed by ß cell failure. Induced pluripotent stem cells can differentiate into functional ß cells. Thus, ß cells from MODY8 patients can be generated in vitro and used for disease modelling and cell replacement therapy. METHODS: A genetic study was performed in a patient suspected of monogenic diabetes. RESULTS: A novel heterozygous pathogenic variant in CEL (c.1818delC) was identified in the proband, allowing diagnosis of MODY8. Three MODY8-iPSC (induced pluripotent stem cell) clones were reprogrammed from skin fibroblasts of the patient, and their pluripotency and genomic stability confirmed. All 3 MODY8-iPSC differentiated into ß cells following developmental stages. MODY8-iPSC-derived ß cells were able to secrete insulin upon glucose dynamic perifusion. The CEL gene was not expressed in iPSCs nor during any steps of endocrine differentiation. CONCLUSION: iPSC lines from a MODY8 patient with a novel pathogenic variant in the CEL gene were generated; they are capable of differentiation into endocrine cells, and ß cell function is preserved in mutated cells. These results set the basis for in vitro modelling of the disease and potentially for autologous ß cell replacement.