Abstract : Aims: Regeneration of myocardial tissue and improvement of myocardial activity after ischemia is one of the major fields of interest in cardiovascular research. We have developed a novel experimental rat model, and used it to examine the effect of mesenchymal stem cell transplantation (MSCT) on myocardial ischemia evaluated by single photon emission computed tomography (SPECT/CT) and immunohistochemistry. Methods and results: Forty adult female Wistar rats underwent open thoracotomy with (n=30) or without (n=10) surgical ligation of the left anterior descending coronary artery (LAD), to create myocardial ischemia, which was confirmed with ECG. Myocardial viability was evaluated via SPECT/CT at 7 days before as well as at 7 and 14 days post-surgery. At day 0, 15 animals received homologous stem cells injected at the ischemic myocardium area. SPECT/CT evaluation confirmed the reduction of functional myocardial cells of the left ventricle one week post-infarction. Regeneration of the ischemic myocardium fifteen days post infarction was recorded, only in animals submitted to stem cell transplantation. Findings were also confirmed by histology and immunohistochemical analysis, with significant higher expression of GATA4 and Nkx2,5. Conclusion: The positive effect of mesenchymal stem cells transplantation in the ischemic myocardium was recorded. The application of SPECT- CT qualitative and quantitative evaluation of myocardial function may lead to a new approach in experimentation with an anticipated significant impact in the ongoing cardiovascular laboratory research. In clinical perspective, MSCT may be beneficial when accompanied with myocardial revascularization procedures.

Emerging data support associations between depletion of the healthy gut microbiome and aging-related physiological decline and disease. In humans, fecal microbiota transplantation (FMT) has been used successfully to restore gut microbiome structure and function to treat C. difficile infections, but application to healthy aging has been scarcely investigated. The marmoset is an excellent model for evaluating microbiome-mediated changes with age and interventional treatments due to their relatively shorter lifespan and many social, behavioral, and physiological functions that mimic human aging. This review 1) provides an overview of the rationale for FMT to support healthy aging using the marmoset as a translational geroscience model, 2) summarizes prior use of FMT in marmosets, 3) outlines a protocol for studying FMT in aging marmosets, and 4) describes knowledge gaps and future research needs in this field.

Although subcutaneous islet transplantation has many advantages, transplant efficiency is still low in animal models, except in mice. We previously reported the efficacy of pretreatment using gelatin hydrogel nonwoven fabric (GHNF) in a mouse model. We investigated whether the preimplantation of GHNF could improve the subcutaneous islet transplantation outcomes in a rat model. GHNF sheets sandwiching a silicone spacer (GHNF group) and silicone spacers without GHNF sheets (control group) were implanted into the subcutaneous space of recipients three weeks before islet transplantation, and diabetes was induced seven days before islet transplantation. Syngeneic islets were transplanted into the space where the silicone spacer was removed. Blood glucose levels, glucose tolerance, immunohistochemistry, and neovascularization were evaluated. The GHNF group showed significantly better blood glucose changes than the control group (p<0.01). The cure rate was significantly higher in the GHNF group (p<0.05). The number of vWF-positive vessels was significantly higher in the GHNF group (p<0.01), and lectin angiography showed the same tendency (p<0.05). The expression of laminin and collagen III around the transplanted islets were also higher in the GHNF group (p<0.01). GHNF pretreatment was effective in a rat model, and the main mechanisms might be neovascularization and compensation of the extracellular matrices.

Treating relapsed and refractory diffuse large B-cell lymphoma is still challenging for clinicians, but the available CAR-T and bispecific antibodies revolutionized therapy. Autologous stem cell transplantation was the most effective treatment modality previously. The authors report data from a single center over ten years. The retrospective study included 116 patients. There were 53 relapsed, 39 primary refractory cases, 19 had CNS involvement, and 5 received primary consolidation transplants. The median duration of follow-up was 46 months. The median event-free survival was 75 months, and the median overall survival was 105 months for all cases. Five-year overall survival was 59%, and event-free survival was 54%. Pretreatment prognostic factors at diagnosis had no effect on the outcome of transplantation. The authors found no difference between survival in relapsed or refractory cases, and the number of salvage lines or the germinal center / activated B-cell type also did not influence the results. Complete metabolic response before transplant confirmed by 18FDG PET/CT strongly affected survival. The pretransplant creatinine and CRP levels significantly influenced the long-term outcome. The number of stem cells infused did not affect survival, but engraftment within nine days did result in better survival. These data support the finding that the response to salvage therapy did select a better prognostic group who may still benefit from autologous transplantation.

BK polyomavirus (BKPyV) is still a real threat in the management of kidney transplantation. Immunosuppressive treatment disrupts the equilibrium between virus replication and immune response, and uncontrolled BKPyV replication leads to nephropathy (BKPyV nephropathy). The first evidence of BKPyV reactivation in transplant recipients is the detection of viral shedding in urine, which appears in 20% to 60% of patients, followed by BKPyV viremia in 10-20% of kidney transplant recipients. BKPyV nephropathy eventually occurs in 1-10% of this population, mainly within the first 2 years post-transplantation, causing graft loss in about half of those patients. Few data exist regarding the pediatric population and we focus on them. In this paper, we review the existing diagnostic methods, we summarize the evidences on the role of BKPyV humoral and cellular immunity in the modulation of the clinical course of BKPyV infection and as potential predictors of the outcome. We look at the known risk factors of BKPyV nephropathy in the immunosuppressed patient. Finally, we propose a sensible clinical attitude in order to screen and manage BKPyV infection in kidney transplant children.

Background & aims: Malnutrition in lung transplant (LT) candidates increases postoperative morbidity and mortality. Early diagnosis of malnutrition could attenuate adverse prognostic factors. This study aimed to assess the prevalence of nutritional risk and malnutrition using GLIM criteria in LT candidates and clinically characterize those with malnutrition. Methods: A prospective longitudinal study was conducted from 2000 to 2020 of LT candidates who underwent complete nutritional assessment (nutritional screening, anthropometry, bioelectrical impedance, blood laboratory tests and malnutrition diagnosis using GLIM criteria). Results: Obstructive diseases (45.6%), interstitial diseases (36.6%) and cystic fibrosis/non-cystic fibrosis bronchiectasis (15.4%) were the main conditions assessed for LT. Of the 1060 candidates evaluated, 10.6% were underweight according to BMI, 29% were at risk of malnutrition and 47% were diagnosed with malnutrition using GLIM criteria. Reduced muscle mass was the most frequent GLIM phenotypic criterion. Malnutrition was more prevalent in patients with cystic fibrosis/non-cystic fibrosis bronchiectasis (84.5%), obstructive (45.4%) and interstitial (31.3%) diseases. GLIM criteria detected some degree of malnutrition in all diseases requiring LT and identified patients with higher CRP levels and worse respiratory function, anthropometric measurements and visceral protein and lipid profiles. Conclusions: LT candidates present a high prevalence of malnutrition using the GLIM algorithm. GLIM criteria detected malnutrition in all diseases requiring LT and defined patients with worse clinical-analytical profiles.

Background: Galectin-3 (Gal-3) overexpression is associated with fibroblastic proliferation and the production of collagen, resulting in increased cardiac fibrosis and remodelling. Aim of the study was to investigate on the expression of Gal-3 in hypertrophic hearts. We examined 19 surgical specimens taken from interventricular septum of 8 patients with Tetralogy of Fallot, 4 patients with aortic valve stenosis, 1 cardiac explant affected from dilated cardiomyopathy, and 6 myocardial biopsies of patients submitted to heart transplantation. Methods: All the samples were routinely processed, stained with Hematoxylin-Eosin, Trichromic stain and elastic fiber stain and selected by having the morphological features of myocardial hy-pertrophy: myocytolysis, nuclear pleomorphism, interstitial fibrosis. Results: At immunohistochemistry, myocardial fibers showed cytoplasmic expression of Gal-3 in the 4 patients with aortic valve stenosis (diffuse in 3 and mild in 1), in the 1 patient with cardiac explant (mild) and in the 4/6 transplanted hearts (mild and focal in 3 and diffuse in 1). The 8 patients affected from Tetralogy of Fallot and 2 patients with transplanted hearts resulted negative. Conclusions: The results agreed with the hypothesis that Gal-3 may play a role in cardiac hyper-trophy; its expression in myocardial fibers is not related with the morphological aspects as suggested by the absence in pediatric cases. The presence in myocardial biopsies taken from transplanted hearts would suggest a possible role in predicting clinical outcome of such patients.

Background: Humoral memory and specific antibodies levels depend on kind of the antigen and individual immunofactors., The presence of IgM antibodies or fourfold rise in specific IgG level, are generally accepted as diagnostic in serology of acute viral infection. This basic model is not adequate for herpesvirome especially after hematopoietic stem cell transplantation (HSCT) due to continuous, usually multifocal antigenic stimulation, various donor serostatus, immunosuppresion and individual immunoreconstitution. Methods: A  case-control study was conducted for identifying cases of Human herpesviruses (HHV) active infection (from 300 diagnosed immunocompromised patients) and evaluating historically associated humoral factors to look at outcomes. We enrolled only patients’ data with meticulous differential diagnosis to exclude other causes, thereby observe pathways and temporal relationships, not statistical ones, usually collected in cohorts. Despite the small number such data collection and analysis avoids a number of biases and indicates cause and effect.Results. In the observational study retrospective analysis of data from 300 patients with clinical diagnosis of herpes simplex (HSV) and varicella zoster virus(VZV) reactivation showed a number of biases. In two well differentiated cases (confirmed by Tzanck test) with various disease and conditioning evolution of immunoparameters showed interesting pathway. Exponential decrease of specific IgG after HSCT precedes virus replication with cytopathic effect (shingles, VZV-encephalitis and HSV-induced mucositis). Minima (smallest IgG levels) before herpes virus reactivation were 234,23 mIU/ml and 94 RU/ml for VZV and HSV, respectively. This coincides with low CD4 titer, but without other infectious process. Other immune response parameters such as Treg, cytotoxic T cells, complement and total IgG level were quite the same as before the transplant procedure. Interestingly, the second wave of immunoreconstitution with anamnestic antibody response was not always observed. It coincided with prolonged herpes viral infection. Patient with lymphocyte depletion in conditioning showed earlier second wave of immunoreconstitution (6th vs 14th month) Conclusions: Typical for infancy kinetics of IgG level is unique after HSCT (the decline phase is first). Host-microbiome factors (i.e. HHV1-3 -serostatus) should be taken into account to predict risk of non-relapse mortality and survival after HSCT. The levels of specific antibodies help to predict the prognosis and improve the management. The lack of differentiation, assessor and confusing bias are the main obstacles in statistical HHV1-3 research. Such time-lapse case studies may be first to build evidence of a pathway and association between immunoparameters and HHV disease.

Background: Xenogenous bone has been proposed as an alternative to overcome the disadvantages of autogenous grafting. The aim of the present study was to study bone dynamics at inlay and onlay xenografts used for bone augmentation applying a ring technique. Methods: The bone at the lateral surface of the mandibular angle of 12 adult male New Zealand White rabbits was exposed bilaterally. The cortical layer received multiple perforations at one side of the mandible and a xenograft block of collagenated cancellous equine bone, 7 mm in diameter and 3 mm in width, was fixed on the prepared surface using an implant (onlay group). On the opposite side, a defect 7 mm in diameter and 3 mm in depth was prepared, the xenograft block was adapted to the defect and fixed with an implant (inlay group). Results: After ten weeks of healing, in the onlay grafts, new bone was mainly formed on the trabeculae surface, reaching in some specimens the most coronal regions of the block. In the inlay grafts, new bone was found arranged on the trabecular surfaces but also occupying the spaces among the trabeculae. The entrance of the defect was often found close at the top of the block by newly formed bone. A higher percentage of new bone was found in the inlay (19.0 ±9.3%) compared to the onlay (10.4 ±7.4%) groups (p=0.031). The mean gain in osseointegration at the implant in relation to the base of the original 3 mm deep defect was 0.95 ±1.05% at the onlay group and 0.78 ±0.71% at the inlay group (p=0.603). Conclusion: The inlay grafts exhibited a higher new bone percentage than the onlay grafts possibly due to the defect conformation that presented more sources for bone formation. The trabecular conformation and the composition of the grafts made possible the expression of the osteoconductive properties of the material used. This resulted, in several specimens, in growth of bone on the graft trabeculae toward the most superior regions in both groups, and in the closure of the coronal entrance of the defects in the inlay group.

Despite notable advancements in immunotherapy in the past decades, allogeneic hematopoietic stem cell transplantation (allo-HCT) remains a promising, potentially curative treatment modality. Only a limited number of studies has performed a direct comparison of two prevalent rabbit anti-thymocyte globulin (r-ATG) formulations — specifically, Thymoglobuline (ATG-T, formerly Genzyme) and Grafalon (ATG-G, formerly Fresenius). The primary objective of our retrospective analysis was to compare the outcomes of adult patients undergoing matched or mismatched unrelated donor (MUD/MMUD) allo-HCT, with a graft-versus-host disease (GvHD) prophylaxis based on either ATG-T or ATG-G. A total of 87 patients undergone allo-HCT between 2012 and 2022 were included. We observed no significant differences between ATG-T and ATG-G concerning the occurrence of acute graft-versus-host disease (aGvHD), regardless of its severity. Conversely, chronic graft-versus-host disease (cGvHD) occurred less frequently in the ATG-T group compared to ATG-G (7.5% vs. 38.3%, p=0.001). Patients treated with ATG-T manifested a higher incidence of cytomegalovirus (CMV) reactivations (70% vs. 31.9%, p<0.001), with a shorter time between transplant and CMV (<61 days, 77.8% vs. 33.3%, p=0.008) and a higher median CMV copy number (1000 vs. 0, p=0.004). Notably, despite a higher occurrence of CMV reactivations in the ATG-T cohort, most patients were asymptomatic compared to ATG-G (85.7% vs. 43.8%, p=0.005). Finally, we observed no significant differences in terms of 5-year overall survival (OS) and 3-year probability of relapse while comparing ATG-T and ATG-G (32.0% vs 40.3%, p=0.423; 63.9% vs 55.7%, p=0.438, respectively).

The literature study delves into novel therapeutic strategies in transplantation medicine, highlighting unique approaches that could revolutionize current practices. It emphasizes novel patterns that have the potential to transform the current landscape. Commencing with a thorough examination of the historical environment, it traces crucial advances and changes in transplantation. The focus is on traditional techniques, emphasizing their limitations and challenges. An extensive examination of contemporary transplantation therapies offers valuable insights into the most recent progress in organ, cellular, and tissue transplantation. This analysis examines the immunological obstacles and outlines the current advancements and constraints. The exploration further navigates into novel models and concepts such as immunomodulation, developments in organ preservation techniques, gene editing, biomaterials, scaffold-based solutions, and the integration of precision medicine, artificial intelligence, and machine learning applications. Each section analyzes the potential for change and current progress in various areas, backed by relevant scientific sources up to 2023. The subsequent sections delve into innovative cellular therapies, biotechnological progress, current clinical trials, and case studies demonstrating effective applications. This examination delves into the ethical and regulatory considerations of innovative therapeutic procedures, emphasizing ethical implications, regulatory frameworks, and the importance of balancing innovation with patient welfare. The literature review concludes by offering a forward-looking perspective, emphasizing potential progress, anticipated challenges, and advocating for collaboration and interdisciplinary approaches to overcome limitations in the field of transplantation medicine.