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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., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Hyperpolarization by dissolution dynamic nuclear polarization (dDNP) provides the opportunity to dramatically increase the weak nuclear magnetic resonance (NMR) signal of liquid molecular targets using the high polarization of electron radicals. Unfortunately, the solution-state hyperpolarization can only be accessed once since freezing and melting of the hyperpolarized sample happen in an irreversible fashion. A way to expand the application horizon of dDNP can therefore be to find a recyclable DNP alternative. To pursue this ambitious goal, we recently introduced the concept of recyclable hyperpolarized flow (HypFlow) DNP where hyperpolarization happens in porous hyperpolarizing solids placed in a compact benchtop DNP polarizer at a magnetic field of 1 T and a temperature of 77 K. Here we aim to optimize the radical concentrations immobilized in hyperpolarizing solids with the objective of generating as much polarization as possible in a timeframe (<1 s) compatible with future recyclable DNP applications. To do so, the solid-state DNP enhancement factors, build-up rates and DNP spectra of different hyperpolarizing solids containing various nitroxide radical loadings (20-74 μmol cm -3 ) are compared against the DNP performance of varying nitroxide concentrations (10-100 mM) solvated in a glassy frozen solution. We demonstrate that in <1 s, polarization enhancement goes up to 56 and 102 with surface-bound and solvated radicals, respectively, under the optimized conditions. For the range of nitroxide concentrations used cross effect DNP seems to be the dominant mechanism under benchtop conditions. This was deduced from the electron paramagnetic resonance (EPR) lineshape of TEMPOL investigated using Q-band EPR measurements.

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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Caldara, Tomajer, Monti, Sordi, Citro, Chimienti, Gremizzi, Catarinella, Tentori, Paloschi, Melzi, Mercalli, Nano, Magistretti, Partelli and Piemonti.)

Aim: In a recent randomized, multicenter trial (NCT02814838) a short-term anti-inflammatory treatment with ladarixin (LDX; an inhibitor of the CXCR1/2 chemokine receptors) did not show benefit on preserving residual beta cell function in new-onset type 1 diabetes. We present a post hoc analysis of trial patients in the predefined subgroup analysis developed according to baseline daily insulin requirement (DIR) tertiles., Method: A double-blind, randomized (2:1), placebo-controlled study was conducted in 45 men and 31 women (aged 18-46 years) within 100 days of the first insulin administration. Patients received LDX (400 mg twice daily) for three cycles of 14 days on/14 days off, or placebo. The primary endpoint was the area under the curve for C-peptide [AUC (0-120 min)] in response to a 2-h mixed meal tolerance test (MMTT) at week 13 ± 1. Seventy-five patients completed the week 13 MMTT and were divided into three groups according to the DIR tertiles: lower, ≤ 0.23U/kg/die (n = 25); middle, 0.24-0.40 U/kg/die (n = 24); upper, ≥ 0.41 U/kg/die (n = 26)., Results: When considering the patients in the upper tertile (HIGH-DIR), C-peptide AUC (0-120 min) at 13 weeks was higher in the LDX group (n = 16) than in the placebo (n = 10) group [difference: 0.72 nmol/L (95% CI 0.9-1.34), p = 0.027]. This difference reduced over time (0.71 nmol/L at 26 weeks, p = 0.04; 0.42 nmol/L at 52 weeks, p = 0.29), while it has never been significant at any time in patients in the lower and/or middle tertile (LOW-DIR). We characterized at baseline the HIGH-DIR and found that endo-metabolic (HOMA-B, adiponectin, and glucagon-to-C-peptide ratio) and immunologic (chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemoattractant protein 1 (MCP1) and Vascular Endothelial Growth Factor (VEGF)) features distinguished this group from LOW-DIR., Conclusion: While LDX did not prevent the progressive loss of beta-cell function in the majority of treated subjects, the post hoc analysis suggests that it could work in subjects with HIGH-DIR at baseline. As we found differences in endo-metabolic and immunologic parameters within this subgroup, this generates the hypothesis that the interactions between host factors and drug action can contribute to its efficacy. Further research is needed to evaluate this hypothesis., Competing Interests: LP served as a consultant for Dompé farmaceutici spa Milan, Italy. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The original clinical trial was funded by Dompé farmaceutici spa Milan, Italy. Each study center received research support and compensation from Dompé farmaceutici spa Milan, Italy to conduct the study and collect data., (Copyright © 2023 Sordi, Monti, Lampasona, Melzi, Pellegrini, Keymeulen, Gillard, Linn, Bosi, Rose, Pozzilli, Giorgino, Cossu and Piemonti.)

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., Competing Interests: The authors report no conflicts of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

NMR-based analysis of metabolite mixtures provides crucial information on biological systems but mostly relies on 1D 1 H experiments for maximizing sensitivity. However, strong peak overlap of 1 H spectra often is a limitation for the analysis of inherently complex biological mixtures. Dissolution dynamic nuclear polarization (d-DNP) improves NMR sensitivity by several orders of magnitude, which enables 13 C NMR-based analysis of metabolites at natural abundance. We have recently demonstrated the successful introduction of d-DNP into a full untargeted metabolomics workflow applied to the study of plant metabolism. Here we describe the systematic optimization of d-DNP experimental settings for experiments at natural 13 C abundance and show how the resolution, sensitivity, and ultimately the number of detectable signals improve as a result. We have systematically optimized the parameters involved (in a semi-automated prototype d-DNP system, from sample preparation to signal detection, aiming at providing an optimization guide for potential users of such a system, who may not be experts in instrumental development). The optimization procedure makes it possible to detect previously inaccessible protonated 13 C signals of metabolites at natural abundance with at least 4 times improved line shape and a high repeatability compared to a previously reported d-DNP-enhanced untargeted metabolomic study. This extends the application scope of hyperpolarized 13 C NMR at natural abundance and paves the way to a more general use of DNP-hyperpolarized NMR in metabolomics studies., Competing Interests: Dmitry Eshchenko, Marc Schnell, Roberto Melzi, and James G. Kempf are employees of Bruker Biospin, which supplied the d-DNP polarizer. It is not a commercial instrument but a step in ongoing Bruker R&D., (Copyright: © 2022 Arnab Dey et al.)

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., (© 2022 The Authors. European Journal of Immunology published by Wiley-VCH GmbH.)

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., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society.)

In the attempt to understand the origin of autoantibody (AAb) production in patients with and at risk for type 1 diabetes (T1D), multiple studies have analyzed and reported alterations in T follicular helper (Tfh) cells in presymptomatic AAb + subjects and patients with T1D. Yet, whether the regulatory counterpart of Tfh cells, represented by T follicular regulatory (Tfr) cells, is similarly altered is still unclear. To address this question, we performed analyses in peripheral blood, spleen, and pancreatic lymph nodes (PLN) of organ donor subjects with T1D. Blood analyses were also performed in living AAb - and AAb + subjects. While negligible differences in the frequency and phenotype of blood Tfr cells were observed among T1D, AAb - , and AAb + adult subjects, the frequency of Tfr cells was significantly reduced in spleen and PLN of T1D as compared with nondiabetic control subjects. Furthermore, adoptive transfer of Tfr cells delayed disease development in a mouse model of T1D, a finding that could indicate that Tfr cells play an important role in peripheral tolerance and regulation of autoreactive Tfh cells. Together, our findings provide evidence of Tfr cell alterations within disease-relevant tissues in patients with T1D, suggesting a role for Tfr cells in defective humoral tolerance and disease pathogenesis., (© 2021 by the American Diabetes Association.)

Aim: The aim of the current study was to compare clinical characteristics, laboratory findings, and major outcomes of patients hospitalized for COVID-19 pneumonia with COVID-associated hyperglycaemia or pre-existing diabetes., Methods: A cohort of 176 adult patients with a diagnosis of pre-existing diabetes ( n = 112) or COVID-associated hyperglycaemia ( n = 55) was studied., Results: Patients with COVID-associated hyperglycaemia had lower BMI, significantly less comorbidities, and higher levels of inflammatory markers and indicators of multi-organ injury than those with pre-existing diabetes. No differences between pre-existing diabetes and COVID-associated hyperglycaemia were evident for symptoms at admission, the humoral response against SARS-CoV-2, or autoantibodies to glutamic acid decarboxylase or interferon alpha-4. COVID-associated hyperglycaemia was independently associated with the risk of adverse clinical outcome, which was defined as ICU admission or death (HR 2.11, 95% CI 1.34-3.31; p = 0.001), even after adjustment for age, sex, and other selected variables associated with COVID-19 severity. Furthermore, at the same time, we documented a negative association (HR 0.661, 95% CI 0.43-1.02; p = 0.063) between COVID-associated hyperglycaemia to swab negativization., Conclusions: Recognizing hyperglycaemia as a specific clinical entity associated with COVID-19 pneumonia is relevant for early and appropriate patient management and close monitoring for the progression of disease severity.

Hyperpolarization by dissolution dynamic nuclear polarization (dDNP) has enabled promising applications in spectroscopy and imaging, but remains poorly widespread due to experimental complexity. Broad democratization of dDNP could be realized by remote preparation and distribution of hyperpolarized samples from dedicated facilities. Here we show the synthesis of hyperpolarizing polymers (HYPOPs) that can generate radical- and contaminant-free hyperpolarized samples within minutes with lifetimes exceeding hours in the solid state. HYPOPs feature tunable macroporous porosity, with porous volumes up to 80% and concentration of nitroxide radicals grafted in the bulk matrix up to 285 μmol g -1 . Analytes can be efficiently impregnated as aqueous/alcoholic solutions and hyperpolarized up to P( 13 C) = 25% within 8 min, through the combination of 1 H spin diffusion and 1 H →  13 C cross polarization. Solutions of 13 C-analytes of biological interest hyperpolarized in HYPOPs display a very long solid-state 13 C relaxation times of 5.7 h at 3.8 K, thus prefiguring transportation over long distances., (© 2021. The Author(s).)

We have recently demonstrated the use of contactless radiofrequency pulse sequences under dissolution-dynamic nuclear polarization conditions as an attractive way of transferring polarization from sensitive 1H spins to insensitive 13C spins with low peak radiofrequency pulse powers and energies via a reservoir of dipolar order. However, many factors remain to be investigated and optimized to enable the full potential of this polarization transfer process. We demonstrate herein the optimization of several key factors by: (i) implementing more efficient shaped radiofrequency pulses; (ii) adapting 13C spin labelling; and (iii) avoiding methyl group relaxation sinks. Experimental demonstrations are presented for the case of [1-13C]sodium acetate and other relevant molecular candidates. By employing the range of approaches set out above, polarization transfer using the dipolar order mediated cross-polarization radiofrequency pulse sequence is improved by factors approaching ∼1.65 compared with previous results. Dipolar order mediated 1H→13C polarization transfer efficiencies reaching ∼76% were achieved using significantly reduced peak radiofrequency pulse powers relative to the performance of highly sophisticated state-of-the-art cross-polarization methods, indicating 13C nuclear spin polarization levels on the order of ∼32.1% after 10 minutes of 1H DNP. The approach does not require extensive pulse sequence optimization procedures and can easily accommodate high concentrations of 13C-labelled molecules.

Aims/hypothesis: The aim of the study was to characterise the humoral response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with diabetes. Demonstrating the ability to mount an appropriate antibody response in the presence of hyperglycaemia is relevant for the comprehension of mechanisms related to the observed worse clinical outcome of coronavirus disease 2019 (COVID-19) pneumonia in patients with diabetes and for the development of any future vaccination campaign to prevent SARS-CoV-2 infection., Methods: Using a highly specific and sensitive measurement of antibodies by fluid-phase luciferase immunoprecipitation assays, we characterised the IgG, IgM and IgA response against multiple antigens of SARS-CoV-2 in a cohort of 509 patients with documented diagnosis of COVID-19, prospectively followed at our institution. We analysed clinical outcomes and antibody titres according to the presence of hyperglycaemia, i.e., either diagnosed or undiagnosed diabetes, at the time of, or during, hospitalisation., Results: Among patients with confirmed COVID-19, 139 (27.3%) had diabetes: 90 (17.7%) had diabetes diagnosed prior to the hospital admission (comorbid diabetes) while 49 (9.6%) had diabetes diagnosed at the time of admission (newly diagnosed). Diabetes was associated with increased levels of inflammatory biomarkers and hypercoagulopathy, as well as leucocytosis and neutrophilia. Diabetes was independently associated with risk of death (HR 2.32 [95% CI 1.44, 3.75], p = 0.001), even after adjustment for age, sex and other relevant comorbidities. Moreover, a strong association between higher glucose levels and risk of death was documented irrespective of diabetes diagnosis (HR 1.14 × 1.1 mmol/l [95% CI 1.08, 1.21], p < 0.001). The humoral response against SARS-CoV-2 in patients with diabetes was present and superimposable, as for timing and antibody titres, to that of non-diabetic patients, with marginal differences, and was not influenced by glucose levels. Of the measured antibody responses, positivity for IgG against the SARS-CoV-2 spike receptor-binding domain (RBD) was predictive of survival rate, both in the presence or absence of diabetes., Conclusions/interpretation: The observed increased severity and mortality risk of COVID-19 pneumonia in patients with hyperglycaemia was not the result of an impaired humoral response against SARS-CoV-2. RBD IgG positivity was associated with a remarkable protective effect, allowing for a cautious optimism about the efficacy of future vaccines against SARs-COV-2 in people with diabetes. Graphical abstract.

Metabolomics plays a pivotal role in systems biology, and NMR is a central tool with high precision and exceptional resolution of chemical information. Most NMR metabolomic studies are based on 1 H 1D spectroscopy, severely limited by peak overlap. 13 C NMR benefits from a larger signal dispersion but is barely used in metabolomics due to ca. 6000-fold lower sensitivity. We introduce a new approach, based on hyperpolarized 13 C NMR at natural abundance, that circumvents this limitation. A new untargeted NMR-based metabolomic workflow based on dissolution dynamic nuclear polarization (d-DNP) for the first time enabled hyperpolarized natural abundance 13 C metabolomics. Statistical analysis of resulting hyperpolarized 13 C data distinguishes two groups of plant (tomato) extracts and highlights biomarkers, in full agreement with previous results on the same biological model. We also optimize parameters of the semiautomated d-DNP system suitable for high-throughput studies.

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., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In December 2018, Diabetes and Diabetologia began requiring authors of papers reporting data obtained from studies on human islets to report critical characteristics of the human islets used for research. The islet community was asked to provide feedback on it. Here is the contribution by the European Consortium for Islet Transplantation., (© 2019 by the American Diabetes Association.)

Background: Results in murine and nonhuman primate suggested that the bone marrow (BM) might be an alternative site for pancreatic islet transplantation., Methods: We report the results of 2 clinical studies in patients with type 1 diabetes receiving an intra-BM allogeneic islet transplantation: a feasibility study in patients with hepatic contraindications for liver islet allotransplantation receiving a single intra-BM islet infusion (n = 4) and a pilot randomized trial (1:1 allocation using blocks of size 6) in which patients were randomized to receive islets into either the liver (n = 6) or BM (n = 3) to evaluate islet transplant function and survival., Results: We observed no adverse events related to the intrabone injection procedure or the presence of islets in the BM. None of the recipient of an intra-BM allogeneic islet transplantation had a primary nonfunction, as shown by measurable posttransplantation C-peptide levels and histopathological evidence of insulin-producing cells or molecular markers of endocrine tissue in BM biopsy samples collected during follow-up. All patients receiving islets in the BM except 1 lost islet function during the first 4 months after infusion (2 with an early graft loss). Based on biopsies and immunomonitoring, we concluded that the islet loss was primarily caused by the recurrence of autoimmunity., Conclusions: Bone marrow is not a suitable alternative site for pancreatic islet allotransplantation in patients with type 1 diabetes.

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., (© 2018 The American Society of Transplantation and the American Society of Transplant Surgeons.)

miR-204 has been proposed to modulate insulin expression in human pancreatic islets by regulating the expression of the MAFA transcript, and in turn insulin transcription. We investigated miR-204 expression in pancreatic endocrine tumors (PET), a panel of human tissues, tissues derived from pancreatic islet purification, and in induced pluripotent stem cells (iPSCs) differentiated towards a pancreatic endocrine phenotype by quantitative real time RT-PCR or droplet digital PCR (ddPCR). In addition, we evaluated the effect of miR-204 up- or down-regulation in purified human islets and in the EndoC-βH1 cell line, as an experimental model of human pancreatic β cells. Our results confirm that miR-204 was enriched in insulin producing PET, in β cells within healthy pancreatic islets, and highly expressed in EndoC-βH1 cells. Moreover, in iPSCs miR-204 increased stepwise upon stimulated differentiation to insulin producing cells. However, up- or down-regulation of miR-204 in human islets and in EndoC-βH1 cells resulted in modest and not significant changes of the MAFA and INS mRNAs measured by ddPCR or c-peptide release. Our data confirm the association of miR-204 with a β cell endocrine phenotype in human pancreatic islets, but do not support its direct role in regulating the levels of insulin mRNA through MAFA.

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.

Background: The aim of this study was to characterize the immune response against intrabone marrow (BM-Tx) or intraliver (liver-Tx) transplanted islets in the presence or in the absence of immunosuppression., Methods: Less (C57BL/6 in Balb/c) and highly (Balb/c in C57BL/6) stringent major histocompatibility complex fully mismatched mouse models were used to evaluate the alloimmune response. Single antigen-mismatched mouse model (C57BL/6 RIP-GP in C57BL/6) was used to evaluate the antigen-specific immune response. Mice received tacrolimus (FK-506, 0.1 mg/kg per day)/mycophenolate mofetil (MMF, 60 mg/kg per day), and anti-CD3 (50 μg/day) either alone or in combination., Results: Transplant site did not impact the timing nor the kinetics of the alloimmune and single antigen-specific memory T cell responses in the absence of immunosuppression or in the presence of MMF/FK-506 combination. On the other hand, the median time to graft rejection was 28 ± 5.2 days and 16 ± 2.6 days (P = 0.14) in the presence of anti-CD3 treatment, 50 ± 12.5 days and 10 ± 1.3 days (P = 0.003) in the presence of anti-CD3/MMF/FK-506 treatment for liver-Tx and BM-Tx, respectively. Anti-CD3 did not differentially reach BM and liver tissues but was more effective in reducing graft associated T cell responses in liver-Tx than in BM-Tx., Conclusions: Islets infused in the BM appear less protected from the adaptive immune response in the presence of the anti-CD3 treatment. This result raises some concerns over the potential of the BM as a site for islet allotransplantation.

Dynamic Nuclear Polarization (DNP) is often achieved by the direct transfer of polarization from electrons to nuclei such as 13 C, induced by microwave saturation of the wings of narrow EPR lines of radicals like trityl. In the indirect approach on the other hand, DNP is used to transfer the polarization from the electrons of radicals such as nitroxides that have broad EPR lines to nuclear spins I = 1 H, followed by cross-polarization (CP) from I = 1 H to S = 13 C or other nuclei with low gyromagnetic ratios. This approach is particularly attractive for S = 15 N, since direct DNP yields modest polarizations P( 15 N) < 4% with build-up times that can be as long as τ DNP ( 15 N) > 2 h. In this paper, we show that CP from 1 H to 15 N at 1.2 K can yield P( 15 N) = 25% with τ CP-DNP ( 15 N) = 10-15 min. After rapid dissolution and transfer to a solution-state NMR spectrometer, a polarization P( 15 N) = 20% was observed at 300 K. The longitudinal relaxation times in solution can be as long as T 1 ( 15 N) > 800 s in favorable cases.

We present novel means to hyperpolarize deuterium nuclei in 13 CD 2 groups at cryogenic temperatures. The method is based on cross-polarization from 1 H to 13 C and does not require any radio-frequency fields applied to the deuterium nuclei. After rapid dissolution, a new class of long-lived spin states can be detected indirectly by 13 C NMR in solution. These long-lived states result from a sextet-triplet imbalance (STI) that involves the two equivalent deuterons with spin I = 1. An STI has similar properties as a triplet-singlet imbalance that can occur in systems with two equivalent I = 12 spins. Although the lifetimes T STI are shorter than T 1 (C z ), they can exceed the life-time T 1 (D z ) of deuterium Zeeman magnetization by a factor of more than 20.