Pancreas Transplantation Research Articles

325.9: Donor-derived cell-free DNA (dd-cfDNA) kinetics during rejection and quiescence after simultaneous pancreas and kidney transplant.

325.9: Donor-derived cell-free DNA (dd-cfDNA) kinetics during rejection and quiescence after simultaneous pancreas and kidney transplant.

P.285: Simultaneous pancreas and kidney transplantation from a small pediatric donor with ipsilateral implantation over aortic cuff.

P.285: Simultaneous pancreas and kidney transplantation from a small pediatric donor with ipsilateral implantation over aortic cuff.

325.4: Pancreas after kidney transplant in Saudi Arabia providing superior results to SPK simultaneous pancreas and kidney transplantation.

325.4: Pancreas after kidney transplant in Saudi Arabia providing superior results to SPK simultaneous pancreas and kidney transplantation.

P.123: Covid -19 infection in simultaneous pancreatic kidney transplant recipients - First case series from Asia.

P.123: Covid -19 infection in simultaneous pancreatic kidney transplant recipients - First case series from Asia.

325.6: Impact of pre-transplant HbA1c levels on pancreas transplant outcomes.

325.6: Impact of pre-transplant HbA1c levels on pancreas transplant outcomes.

P.258: Effective financial preparedness for kidney and pancreas transplant patients.

P.258: Effective financial preparedness for kidney and pancreas transplant patients.

325.3: A comparative analysis of pancreas transplant outcomes in type 1 and type 2 diabetes recipients at a single center.

325.3: A comparative analysis of pancreas transplant outcomes in type 1 and type 2 diabetes recipients at a single center.

Outcome-Orientated Organ Allocation-A Composite Risk Model for Pancreas Graft Evaluation and Acceptance.

Background: Pancreas transplantation (PTX) remains the most effective treatment to prevent long-term complications and provide consistent euglycemia in patients with endocrine pancreatic insufficiency, mainly in type I diabetic patients. Considering early graft loss (EGL) and the perioperative complication rate, an optimal risk stratification based on donor risk factors is paramount. Methods: In our single-center study, we retrospectively assessed the risk factors for EGL and reduced graft survival in 97 PTXs (82 simultaneous pancreas and kidney [SPK], 11 pancreases transplanted after kidney [PAK] and 4 pancreases transplanted alone [PTA]) between 2010 and 2021. By statistically analyzing the incorporation of different donor risk factors using the Kaplan-Meier method and a log-rank test, we introduced a composite risk model for the evaluation of offered pancreas grafts. Results: The overall EGL rate was 6.5%. In the univariate analysis of donor characteristics, age > 45 years, BMI > 25 kg/m2, lipase > 60 U/L, cerebrovascular accident (CVA) as the cause of death, mechanical cardiopulmonary resuscitation (mCPR), cold ischemia time (CIT) > 600 min and retrieval by another center were identified as potential risk factors; however, they lacked statistical significance. In a multivariate model, age > 45 years (HR 2.05, p = 0.355), BMI > 25 kg/m2 (HR 3.18, p = 0.051), lipase > 60 U/L (HR 2.32, p = 0.148), mCPR (HR 8.62, p < 0.0001) and CIT > 600 min (HR 1.89, p = 0.142) had the greatest impact on pancreas graft survival. We subsumed these factors in a composite risk model. The combination of three risk factors increased the rate of EGL significantly (p = 0.003). Comparing the pancreas graft survival curves for ≥3 risk factors to <3 risk factors in a Kaplan-Meier model revealed significant inferiority in the pancreas graft survival rate (p = 0.029). Conclusions: When evaluating a potential donor organ, grafts with a combination of three or more risk factors should only be accepted after careful consideration to reduce the risk of EGL and to significantly improve outcomes after PTX.

Liver and pancreas transplantation in adult donor and recipients with situs inversus totalis: a case series and review of the literature

BackgroundSitus inversus totalis is a rare congenital anomaly characterized by a mirror-image orientation of abdominal, and in some cases, thoracic organs. Here, we report our situs inversus totalis transplantation experience and further review liver transplantations in adult recipients and donors with situs inversus totalis.Case presentationWe describe three cases with situs inversus totalis. The first case was liver transplantation in a recipient (a 61-year-old Iranian man) with situs inversus totalis, the second was a liver transplantation from a donor (a 52-year-old Iranian woman) with situs inversus totalis, and finally, for the first time, a simultaneous pancreas and kidney transplantation in a recipient (a 26-year-old Iranian man) with situs inversus totalis. In patient one, hepatectomy could be performed according to the standard method and on the basis of preoperative studies. Hepatic vein and arterial anastomosis were performed as in every other patient without situs inversus totalis. To prevent biliary complications, a Roux-en-Y hepaticojejunostomy was performed. In patient two, implantation time, suprahepatic vein, portal vein, arterial, and biliary reconstruction could be done as in any other case without situs inversus totalis. Plication of the right-sided diaphragm and fixation of the falciform ligament was done for our patient. In patient three, systemic drainage was preferred to portal flow for establishing the outflow drainage of the pancreas compared with otherwise normal patients.ConclusionAlthough situs inversus totalis is a rare condition, our reported techniques are suitable, considering advantages such as easier accessibility, more acceptable placement of the implanted organs regarding vascular variations, and the appropriate location of the allograft in the proximity of other organs.

Delayed peak antibody titers after the second dose of SARS-CoV-2 vaccine in solid organ transplant recipients: Prospective cohort study

Poor post-vaccination production of antibody against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a concern among solid organ transplant (SOT) recipients. Furthermore, the timing and kinetics of antibody titers after the second vaccine dose are unknown. We conducted a multicenter prospective observational study that included 614 SOT recipients: 460 kidney, 53 heart, 50 liver, 20 lung, and 31 simultaneous pancreas–kidney (SPK). The participants received two doses of the mRNA vaccine (Pfizer BNT162b2 or Moderna mRNA-1273), as indicated. Serum samples were collected before the first and second vaccinations and at 1, 3, and 6 months after the second vaccine dose, which were then assessed for SARS-CoV-2 antibodies. The overall seropositivity rate was 43% at 1 month after administration of the second vaccine dose; it gradually increased to 68% at 3 months after second dose administration and to 70% at 6 months. In addition, recipient of kidney, lung or SPK transplants had lower antibody titers at the 3- and 6-month time points than did the other recipients. SOT recipients acquired SARS-CoV-2 S-IgG antibodies slowly, and the peak titer differed significantly from that of the general population.

An investigation of functionalized chitosan and alginate multilayer conformal nanocoating on mouse beta cell spheroids as a model for pancreatic islet transplantation

Multilayer conformal coatings have been shown to provide a nanoscale barrier between cells and their environment with adequate stability, while regulating the diffusion of nutrition and waste across the cell membrane. The coating method aims to minimize capsule thickness and implant volume while reducing the need for immunosuppressive drugs, making it a promising approach for islet cell encapsulation in clinical islet transplantation for the treatment of Type 1 diabetes. This study introduces an immunoprotective nanocoating obtained through electrostatic interaction between quaternized phosphocholine-chitosan (PC-QCH) and tetrahydropyran triazole phenyl-alginate (TZ-AL) onto mouse β-cell spheroids. First, successful synthesis of the proposed polyelectrolytes was confirmed with physico-chemical characterization. A coating with an average thickness of 540 nm was obtained with self-assembly of 4-bilayers of PC-QCH/TZ-AL onto MIN6 β-cell spheroids. Surface coating of spheroids did not affect cell viability, metabolic activity, or insulin secretion, when compared to non-coated spheroids. The exposure of the polyelectrolytes to THP-1 monocyte-derived macrophages lead to a reduced level of TNF-α secretion and exposure of coated spheroids to RAW264.7 macrophages showed a decreasing trend in the secretion of TNF-α and IL-6. In addition, coated spheroids were able to establish normoglycemia when implanted into diabetic NOD-SCID mice, demonstrating in vivo biocompatibility and cellular function. These results demonstrate the ability of the PC-QCH/TZ-AL conformal coating to mitigate pro-inflammatory responses from macrophages, and thus can be a promising candidate towards nanoencapsulation for cell-based therapy, particularly in type 1 diabetes, where the insulin secreting β-cells are subjected to inflammation and immune cell attack.

Cell-mediated Immunity to Guide Primary Prophylaxis for CMV Infection in Organ Transplant Recipients: A Multicenter Single-arm Prospective Study.

There are few interventional studies using CMV cell-mediated immunity (CMI) to guide antiviral prophylaxis. We assessed the Quantiferon-CMV (QTF-CMV) assay to guide CMV prophylaxis duration in high-risk organ transplant recipients. A single-arm, multicenter, prospective interventional study including high-risk kidney, pancreas, liver, and heart transplant recipients who were either donor CMV-seropositive, recipient-seronegative (D+/R-) or recipient-seropositive with antithymocyte globulin (R+/ATG) induction. CMI testing was performed using the QTF-CMV assay at months 3, 4, 5, and 6 posttransplant. Prophylaxis was discontinued for a positive CMI but continued for a negative result up to a maximum of 6 mo. The primary endpoint was CMV viremia ≥1000 IU/mL up to 1 y posttransplant. One hundred eight patients were included, comprising kidney (n = 89), kidney-pancreas (n = 7), liver (n = 10), and heart (n = 2) transplants. Eighty-nine patients (82.4%) completed the study protocol (n = 39 D+/R- and n = 50 R+/ATG). In the D+/R- group, only 1 of 39 patients (2.6%) had a positive QTF-CMV result. In the R+/ATG group, 33 of 50 patients (66%) had a positive QTF-CMV result before 6 mo, allowing for early discontinuation of prophylaxis (28 at month 3, 4 at month 4, and 1 at month 5). During the follow-up, CMV viremia ≥1000 IU/mL occurred in only 4 of 33 patients (12.1%) who discontinued prophylaxis early compared with 6 of 17 patients (35.3%) with negative QTF-CMV results and continued prophylaxis (hazard ratio 0.31; 95% confidence interval, 0.09-1.09; P = 0.07). No R+ patient developed CMV disease. QTF-CMV-guided prophylaxis appears useful in R+ patients who may benefit from a tailored duration of prophylaxis. This strategy does not appear to be useful in D+/R- patients.

Generation of Insulin-Producing Cells from Canine Bone Marrow-Derived Mesenchymal Stem Cells: A Preliminary Study.

Cell-based therapy using insulin-producing cells (IPCs) is anticipated as an alternative treatment option to insulin injection or pancreatic islet transplantation for the treatment of diabetes mellitus in both human and veterinary medicine. Several protocols were reported for the differentiation of mesenchymal stem cells (MSCs) into IPCs; to date, glucose-responsive IPCs have only been obtained from canine adipose tissue-derived MSCs (cAD-MSCs), but not from canine bone marrow-derived MSCs (cBM-MSCs). Therefore, this study aims to generate in vitro glucose-responsive IPCs from cBM-MSCs using two differentiation protocols: a two-step protocol using trichostatin (TSA) and a three-step protocol using mercaptoethanol to induce pancreatic and duodenal homeobox gene 1 (PDX-1) expression. A single experiment was carried out for each protocol. BM-MSCs from one dog were successfully cultured and expanded. Cells exposed to the two-step protocol appeared rarely grouped to form small clusters; gene expression analysis showed a slight increase in PDX-1 and insulin expression, but no insulin protein production nor secretion in the culture medium was detected either under basal conditions or following glucose stimulation. Conversely, cells exposed to the three-step protocol under a 3D culture system formed colony-like structures; insulin gene expression was upregulated compared to undifferentiated control and IPCs colonies secreted insulin in the culture medium, although insulin secretion was not enhanced by high-glucose culture conditions. The single experiment results suggest that the three-step differentiation protocol could generate IPCs from cBM-MSCs; however, further experiments are needed to confirm these data. The ability of IPCs from cBM- MSCs to produce insulin, described here for the first time, is a preliminary interesting result. Nevertheless, the IPCs' unresponsiveness to glucose, if confirmed, would affect its clinical application. Further studies are necessary to establish a differentiation protocol in this perspective.

Adipose tissue–derived mesenchymal stem cells promote the vascularization of pancreatic islets transplanted into decellularized pancreatic skeletons

We have recently developed a model of pancreatic islet transplantation into a decellularized pancreatic tail in rats. As the pancreatic skeletons completely lack endothelial cells, we investigated the effect of co-transplantation of mesenchymal stem cells and endothelial cells to promote revascularization.Decellularized matrix of the pancreatic tail was prepared by perfusion with Triton X-100, sodium dodecyl sulfate and DNase solution. Isolated pancreatic islets were infused into the skeletons via the splenic vein either alone, together with adipose tissue–derived mesenchymal stem cells (adMSCs), or with a combination of adMSCs and rat endothelial cells (rat ECs). Repopulated skeletons were transplanted into the subcutaneous tissue and explanted 9 days later for histological examination. Possible immunomodulatory effects of rat adMSCs on the survival of highly immunogenic green protein–expressing human ECs were also tested after their transplantation beneath the renal capsule. The immunomodulatory effects of adMSCs were also tested in vitro using the Invitrogen Click-iT EdU system.In the presence of adMSCs, the proliferation of splenocytes as a response to phytohaemagglutinin A was reduced by 47% (the stimulation index decreased from 1.7 to 0.9, P = 0.008) and the reaction to human ECs was reduced by 58% (the stimulation index decreased from 1.6 to 0.7, P = 0.03). Histological examination of the explanted skeletons seeded only with the islets showed their partial disintegration and only a rare presence of CD31-positive cells. However, skeletons seeded with a combination of islets and adMSCs showed preserved islet morphology and rich vascularity. In contrast, the addition of syngeneic rat ECs resulted in islet-cell necrosis with only few endothelial cells present. Live green fluorescence–positive endothelial cells transplanted either alone or with adMSCs were not detected beneath the renal capsule.Though the adMSCs significantly reduced in vitro proliferation stimulated by either phytohaemagglutinin A or by xenogeneic human ECs, in vivo co-transplanted adMSCs did not suppress the post-transplant immune response to xenogeneic ECs. Even in the syngeneic model, ECs co-transplantation did not lead to sufficient vascularization in the transplant area. In contrast, islet co-transplantation together with adMSCs successfully promoted the revascularization of extracellular matrix in the subcutaneous tissue.

Accessibility of Percutaneous Biopsy in Retrocolic-Placed Pancreatic Grafts With a Duodeno-Duodenostomy.

Duodeno-duodenostomy (DD) has been proposed as a more physiological alternative to conventional duodeno-jejunostomy (DJ) for pancreas transplantation. Accessibility of percutaneous biopsies in these grafts has not yet been assessed. We conducted a retrospective study including all pancreatic percutaneous graft biopsies requested between November 2009 and July 2021. Whenever possible, biopsies were performed under ultrasound (US) guidance or computed tomography (CT) guidance when the US approach failed. Patients were classified into two groups according to surgical technique (DJ and DD). Accessibility, success for histological diagnosis and complications were compared. Biopsy was performed in 93/136 (68.4%) patients in the DJ group and 116/132 (87.9%) of the DD group (p = 0.0001). The graft was not accessible for biopsy mainly due to intestinal loop interposition (n = 29 DJ, n = 10 DD). Adequate sample for histological diagnosis was obtained in 86/93 (92.5%) of the DJ group and 102/116 (87.9%) of the DD group (p = 0.2777). One minor complication was noted in the DD group. The retrocolic position of the DD pancreatic graft does not limit access to percutaneous biopsy. This is a safe technique with a high histological diagnostic success rate.

Posttransplant Lymphoproliferative Disease Following Pancreas Transplantation: A 40 Year Single-Center Experience.

Chronic immunosuppression following pancreas transplantation carries significant risk, including posttransplant lymphoproliferative disease (PTLD). We sought to define the incidence, risk factors, and long-term outcomes of PTLD following pancreas transplantation at a single center. All adult pancreas transplants between February 1, 1983 and December 31, 2023 at the University of Minnesota were reviewed, including pancreas transplant alone (PTA), simultaneous pancreas-kidney transplants (SPK), and pancreas after kidney transplants (PAK). Among 2353 transplants, 110 cases of PTLD were identified, with an overall incidence of 4.8%. 17.3% were diagnosed within 1 year of transplant, 32.7% were diagnosed within 5 years, and 74 (67.3%) were diagnosed after 5 years. The overall 30-year incidence of PTLD did not differ by transplant type-7.4% for PTA, 14.2% for SPK, and 19.4% for PAK (p = 0.3). In multivariable analyses, older age and Epstein-Barr virus seronegativity were risk factors for PTLD, and PTLD was a risk factor for patient death. PTLD-specific mortality was 32.7%, although recipients with PTLD had similar median posttransplant survival compared to those without PTLD (14.9 year vs. 15.6 year, p = 0.9). PTLD following pancreas transplantation is associated with significant mortality. Although the incidence of PTLD has decreased over time, a high index of suspicion for PTLD following PTx should remain in EBV-negative recipients.

Matrix design for optimal pancreatic β cells transplantation

New therapeutic approaches to treat type 1 diabetes mellitus relies on pancreatic islet transplantation. Here, developing immuno-isolation strategies is essential to eliminate the need for systemic immunosuppression after pancreatic islet grafts. A solution is the macro-encapsulation of grafts in semipermeable matrixes with a double function: separating islets from host immune cells and facilitating the diffusion of insulin, glucose, and other metabolites.This study aims to synthesize and characterize different types of gelatin-collagen matrixes to prepare a macro-encapsulation device for pancreatic islets that fulfill these functions. While natural polymers exhibit superior biocompatibility compared to synthetic ones, their mechanical properties are challenging to reproduce. To address this issue, we conducted a comparative analysis between photo-crosslinked gelatin matrixes and chemically crosslinked collagen matrixes. We show that the different crosslinkers and polymerization methods influence the survival and glucose-stimulated insulin production of pancreatic β cells (INS1) in vitro, as well as the in vitro and in vivo stability of the matrix and the immuno-isolation in vivo.Among the matrixes, the stiff multilayer GelMA matrixes (8.5 kPa), fabricated by digital light processing, were the best suited for pancreatic β cells macro-encapsulation regarding these parameters. Within the alveoli of this matrix, pancreatic β cells spontaneously formed aggregates.

Comparison between the outcome of pancreaticogastrostomy and pancreaticojejunostomy after pancreaticoduodenectomy: a cross-sectional study

Background: Complications of pancreatic stump reconstruction after pancreaticoduodenectomy (PD) can lead to severe morbidity or even mortality. This study is taken to see the postoperative outcome of pancreatico-gastrostomy (PG) over pancreaticojejunostomy (PJ) after PD. Aim of the study was to compare the outcomes of PG and PJ following PD in a cross-sectional analysis. Methods: This comparative cross-sectional study was done in the department of hepatobiliary pancreatic and liver transplant surgery, BSMMU, Dhaka. A total of twenty-five patients (N=25), who underwent PD from July 2019 to June 2020, were included in this study. These patients were divided into two group, group A with PG (n=10) and group B with PJ (n=15). All patients were evaluated before and after surgery for assessing post-operative outcome by clinically, biochemically and radiologically. Results: This study showed no significant differences in demographic characteristics, co-morbidity and post-operative outcomes/complications between this two groups. However, PG demonstrated significantly shorter anastomosis time and required fewer sutures than PJ. Although a higher incidence of wound infections was observed in PJ compared to PG, these differences were not statistically significant. Peri-operative mortality did not significantly differ between the two techniques. Though postoperative hospital stay was shorter in the PG group compared to PJ but the difference was not statistically significant. Conclusions: PG can be considered as a safe and alternative procedure after PD.

Pancreas transplantation: review.

Pancreas transplant (PTx) is the only treatment that establishes normal glucose levels for patients diagnosed with diabetes types 1 and 2. The paper aims to review and analyze graft survival, patient survival, and the impact on diabetic complications. We describe that the graft survival was 82-98% at 1 year, 90% at 5 years, and 75-54% at 10 years for simultaneous pancreas-kidney recipient; 71% pancreas after kidney (PAK), and 62% PTx alone at 1 year. Patient survival: At 1 year for recipients was 96.9% simultaneous pancreas-kidney transplantation (SPK); for PAK transplantation recipients, 96.3%; and for PTx alone recipients, 98.3%. In general, the pancreas transplantation improves and reverses diabetic complications. Finally, the pancreatic transplant is a morbid procedure and emerges as a significant alternative in diabetes management, directly competing with conventional insulin therapies. Results so far suggest that the most effective transplant model is the SPK. While more patients could benefit from this procedure, surgical complications and the need for immunosuppression pose significant challenges.

Exploring Novel Treatment Modalities for Type 1 Diabetes Mellitus: Potential and Prospects.

Despite the effectiveness of insulin injections in managing hyperglycemia in type 1 diabetes mellitus (T1DM), they fall short in addressing autoimmunity and regenerating damaged islets. This review aims to explore the potential and prospects of emerging treatment modalities for T1DM, including mesenchymal stem cells (MSCs), MSC-derived exosomes, gene therapy, islet allotransplantation, pancreatic islet cell transplantation, and teplizumab. We review emerging treatment modalities for T1DM, highlighting several promising strategies with varied mechanisms and outcomes. Mesenchymal stem cells demonstrate potential in modulating the immune response and preserving or restoring beta-cell function, although variability in sources and administration routes necessitates further standardization. Similarly, MSC-derived exosomes show promise in promoting beta-cell regeneration and immune regulation, supported by early-stage studies showing improved glucose homeostasis in animal models, albeit with limited clinical data. Gene therapy, utilizing techniques like CRISPR-Cas9, offers targeted correction of genetic defects and immune modulation; however, challenges in precise delivery and ensuring long-term safety persist. Islet allotransplantation and pancreatic islet cell transplantation have achieved some success in restoring insulin independence, yet challenges such as donor scarcity and immunosuppression-related complications remain significant. Teplizumab, an anti-CD3 monoclonal antibody, has demonstrated potential in delaying T1DM onset by modulating immune responses and preserving beta-cell function, with clinical trials indicating prolonged insulin production capability. Despite significant progress, standardization, long-term efficacy, and safety continue to pose challenges across these modalities. Conclusion: While these therapies demonstrate significant potential, challenges persist. Future research should prioritize optimizing these treatments and validating them through extensive clinical trials to enhance T1DM management and improve patient outcomes.