ARTICLE | doi:10.20944/preprints202205.0098.v1
Subject: Life Sciences, Virology Keywords: COVID-19; pediatric liver transplantation; immunosuppression; living donor liver transplantation
Online: 9 May 2022 (03:59:57 CEST)
Background: COVID-19 infection has received the attention of the scientific community due its respiratory manifestations and association with evolution to severe acute respiratory syndrome (SARS-CoV-2). There are few studies characterizing SARS-CoV-2 in pediatric immunocompromised patients, such as liver transplanted (LT) patients.The aim of this study was to analyze the outcomes of the larger cohort of pediatric liver transplant recipients (PLTR) from a single center in Brazil who where contaminated with COVID-19 during the pandemic. Methods: Cross-sectional study. Primary outcomes: COVID-19 severity. The Cox regression method was used to determine independent predictors associated with the outcomes. Results: 74 PLTR were included. Patients were divided into two groups according to the severity of COVID-19 disease: moderate-severe COVID and asymptomatic-mild COVID. Patients categorized as moderate-severe COVID were younger (12.6 months vs. 82.1 months, p 0.03), higher prevalence of transplantation with deceased donor (50% vs. 4.3%, p 0.02) and with a higher prevalence of COVID-infected patients before 6 months after LT (75% vs. 5.7%, p 0.002). The independent predictor of COVID-19 severity identified in the multivariate analysis was COVID-19 infection < 6 months after LT (HR=0.001, 95% CI=0.001-0.67, p 0.03). Conclusion: The time interval of less than 6 months between COVID-19 infection and LT was the only predictor of disease severity in pediatric patients.
REVIEW | doi:10.20944/preprints202010.0631.v1
Subject: Biology, Anatomy & Morphology Keywords: Coral Growth; Microfragmentation; Transplantation; Zeolite
Online: 30 October 2020 (09:01:07 CET)
Coral reef is an important underwater ecosystem that is rich in biodiversity in it. Coral growth has decreased drastically due to physical and chemical threats, such as the effect of warming seawater, fish bombing activities, and the effects of wastewater. The efficiency level of coral transplantation is determined by many factors, including the stability of the environment's physical condition, the level of coral diversity, and the method of transplantation. The influence of the planting medium can also be a key factor in succeeding the coral transplantation process. The use of stable and natural growing media can be a solution to replace conventional growing media that have been used. Zeolite material is a medium that has many advantages such as amending the trace elemental contents of saltwater such as carbon absorbents, detoxifiers, ammonia remover, catalysts, promoting marine micro-algal growth, become a media for bacterial growth, etc. This review discusses the possibility of zeolites as the candidate media that can be used as a new medium in coral transplantation process to accelerate coral growth and maintain coral health by increasing the adaptation of corals to the effects of global climate change.
CASE REPORT | doi:10.20944/preprints201812.0243.v1
Subject: Medicine & Pharmacology, Other Keywords: technique, transplantation, cadaveric, donor, retrieval
Online: 20 December 2018 (09:39:52 CET)
Aim: To describe a technique for retrieval of abdominal organs of a cadaveric donor Methods: Only the inner transverse transection of abdominal wall floors except skin was performedResults: The good exposure of abdominal closure with the retrieval of the liver, both kidneys and spleen easily.Conclusion: The technique can be feasible in cadaveric organ retrieval from the abdomen.
REVIEW | doi:10.20944/preprints202302.0067.v1
Subject: Life Sciences, Microbiology Keywords: fecal microbiota transplantation; horse; gut microbiota
Online: 3 February 2023 (09:50:36 CET)
Equine fecal microbiota transplantation (FMT) is an emerging therapy for restoring gut microbiome balance in horses. An imbalance in the gut microorganisms, known as dysbiosis, can cause inflammation and metabolic disruptions. FMT, which involves transferring gut bacteria from a healthy donor to a diseased recipient, has shown positive results in treating gastrointestinal diseases in horses, but is still largely limited to research purposes due to safety concerns and lack of understanding of its mechanisms. This paper aims to shed light on the possible mechanisms of FMT in horses and discuss future perspectives for its clinical application. Further research is needed to develop more effective and safer FMT techniques for horses.
REVIEW | doi:10.20944/preprints202206.0260.v1
Subject: Life Sciences, Microbiology Keywords: canine; fecal microbiota transplantation; treatment; mechanism
Online: 20 June 2022 (05:49:24 CEST)
Fecal microbiota transplantation (FMT) is an emerging therapeutic option for a variety of diseases, which is characterized as transferring fecal microorganisms from a healthy donor into the intestinal tract of a diseased receipt. In human clinics, FMT has been used for treating diseases for decades with promising results. In recent years, veterinary specialists adapted FMT in canine patients, however, compared to humans, canine FMT is more inclined to research purposes than practical applications in most cases due to safety concerns. Therefore, in order to facilitate the application of fecal transplant therapy in dogs, in this paper, we aimed to review recent application of FMT in canine clinical treatments as well as possible mechanisms that are involved in the process of therapeutic effect of FMT.
REVIEW | doi:10.20944/preprints202110.0167.v1
Subject: Medicine & Pharmacology, Other Keywords: parasites; microbiota; faecal microbiota transplantation (FMT)
Online: 11 October 2021 (14:20:22 CEST)
A growing body of evidences is showing that dysbiotic gut microbiota may correlate with a wide range of disorders; hence, the clinical use of microbiota maps and fecal microbiota transplantation (FMT) can be exploited in the clinic of some infectious diseases. Through direct or indirect ecological and functional competition, FMT may stimulate decolonization of pathogens or opportunistic pathogens, modulating immune response and colonic inflammation, and restoring intestinal homeostasis, with reduction of host damage. Herein, we discuss how diagnostic parasitology may contribute to design clinical metagenomics pipelines and FMT programs, especially in pediatric subjects. The consequences of a more specialized diagnostics in the context of gut microbiota communities may improve the clinical parasitology and extend its applications to the prevention and treatment of several communicable and even noncommunicable disorders.
REVIEW | doi:10.20944/preprints202003.0434.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: solid-organ transplantation; COVID-19; immunosuppression
Online: 29 March 2020 (11:20:10 CEST)
Many centers worldwide raised the concern that immunocompromised patients for solid organ transplantation may be at high risk of developing a severe respiratory disease by COVID-19. Currently, there are no specific data on the COVID-19 in patients with generalized immunosuppression and transplantation.In this narrative review, we reported the main data of COVID-19 in patients with solid organ transplantation presented in the literature. The aim is to elaborate a strategy for tailored management, from diagnosis to therapy.The management of adult patients with solid organ transplantation and COVID-19 is a challenge for the clinicians. There is a lack of data in the literature, but three key-points are crucial: in the “pandemic era,” consider the symptomatic patient as positive for COVID-19 until proven otherwise; adjust/stop immunosuppressive agents; protect graft function with adequate route and dose administration of glucocorticoid and supportive measures. For pediatric patients, data are scarce. It is unclear if immunosuppression in patients with solid organ transplantation alters the predisposition to acquiring COVID-19 or if the disease implications are modified for better or for worse. Further studies are needed.
ARTICLE | doi:10.20944/preprints201901.0124.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: organ transplantation; immunosuppressant; radiopaque agents; interference
Online: 18 January 2019 (10:31:00 CET)
Background: Immunosuppressant blood levels should be measured at regular periods in order to keep them within the therapeutic index. Although LC-MS/MS is preferred as a reliable method, some molecules like radiopaque agents in blood matrix may lead to false results. The aim of this study is to investigate the effect of seven different radiopaque agents on immunosuppressant drugs. Methods: Seven different radiopaque agents were added into control materials containing tacrolimus, everolimus, sirolimus and cyclosporine A drugs. Measurements were performed by LC-MS/MS instrument. The amount of deviations from target values were calculated. Results: Immunosuppressant blood levels significantly changed after the administration of radiopaque agents. Seven different radiopaque products led to false negative results in tacrolimus and cyclosporine A levels at a rate of 19.77% to 44.45%. The smallest deviations were seen in everolimus levels with administration of RM6 (gadodiamide) and in sirolimus levels with RM1 (gadobutrol) at rates of 4.04% and 2.11%, respectively. The highest deviations were observed with RM3 (iohexol) administration in everolimus and sirolimus levels at rates of 153.72% and 171.41%, respectively. Conclusions: False immunosuppressant results associated with radiopaque agents may result in organ rejection. Preferring radiopaque agents that cause the least interference risk is important to reduce the organ rejection risk. However, the least risky method is to obtain samples for drug levels before contrast-enhanced imaging.
ARTICLE | doi:10.20944/preprints202204.0060.v1
Subject: Medicine & Pharmacology, Other Keywords: kidney transplantation; belatacept; calcineurin inhibitor; transcriptome; RNAseq
Online: 7 April 2022 (12:31:09 CEST)
In kidney transplant recipients, belatacept is usually pursued indefinitely after it has been started. In the setting of the belatacept shortage and after having evaluated the benefit-risk ratio, we established a strategy consisting of time-limited belatacept therapy / transient calcineurin inhibitor withdrawal, whose results are analyzed in that study. We considered all the kidney transplant recipients that had been switched from conventional immunosuppressive therapy to belatacept and then for whom belatacept has been withdrawn intentionally. Furthermore, in the first 8 patients, we assessed changes in peripheral blood mononuclear cells (PBMC) transcriptome using RNAseq before and 3 months after belatacept withdrawal. Over the study period, 28 out of 94 patients had belatacept intentionally withdrawn including 25 (89%) switched to low-dose CNI. One rejection due to poor compliance occurred. The eGFR after 12 months remained stable from 48 ± 19 ml.1.73m-2 to 46 ±17 ml.1.73m-2 (p = 0.68). However, patients that resumed belatacept / withdrew CNIs (n=10) had a trend towards a better eGFR comparing with the others (n =15): 54 ± 20 ml.1.73m-2 vs eGFR 43 ± 16 ml.1.73m-2 respectively (p = 0.15). The only factor associated with belatacept resumption was when the withdrawal took place during the COVID-19 outbreak. Transcriptome analysis of PBMCs, did not support rebound in alloimmune response. These findings underpin the use of belatacept as part of a time-limited therapy, in selected kidney transplant recipients, possibly as an approach to allow efficient vaccination against SARS-Cov-2.
REVIEW | doi:10.20944/preprints202109.0228.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: gut microbiota; critically ill; faecal microbial transplantation; multiorgan
Online: 14 September 2021 (09:52:56 CEST)
The human gut microbiota consists of bacteria, archaea, fungi, and viruses. It is a dynamic ecosystem shaped by several factors, which play an essential role in both healthy and diseased states of humans. A disturbance of the gut microbiota, also termed “dysbiosis,” is associated with increased host susceptibility to a range of diseases. Because of splanchnic ischaemia, exposure to antibiotics, and/or underlying the disease critically ill patients loose 90% of the commensal organisms in their gut within hours after the insult. This is followed by a rapid overgrowth of potentially pathogenic and pro-inflammatory bacteria altering metabolic, immune, and even neurocognitive functions and turning the gut into the driver of systemic inflammation and multiorgan failure. Indeed, restoring healthy microbiota by means of faecal microbiota transplantation (FMT) in the critically ill is an attractive and plausible concept in intensive care. Yet, available data from controlled studies are limited to probiotics and FMT for severe C. difficile infection or severe inflammatory bowel disease. Case series and observational trials generate hypothesis that FMT might be feasible and safe in immunocompromised patients, refractory sepsis, or severe antibiotic-associated diarrhea in ICU. There is a burning need to test these hypotheses in randomized controlled trials powered for determination of patient-centered outcomes.
ARTICLE | doi:10.20944/preprints201912.0394.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: physical activity; elderly population; mediastinal lymphomas; cardiac transplantation
Online: 30 December 2019 (09:35:38 CET)
The incidence of post transplantation lymphoproliferative disorders (PTLDs) and other neoplasms in organ transplant patients is higher than in the non-transplanted population. This event is more frequent in older subjects, due, at least in part, to the immune dysfunction induced by immunosuppressants administered to prevent rejection. Alterations of the immune system mechanisms of protection against carcinogenesis appear to be the key role in the in the pathogenesis of these neoplasms. The data of our study on the incidence of neoplasms occurred during a long-term follow-up in an elderly population after they underwent cardiac transplantation. This study gives, also evidence of the favorable effect of physical activity programs on cardiorespiratory and psychomotor function.
COMMUNICATION | doi:10.20944/preprints202203.0162.v1
Subject: Medicine & Pharmacology, Other Keywords: Mucorales; pulmonary mucormycosis; hematologic malignancy; transplantation; fungal culture; histopathology
Online: 11 March 2022 (07:59:01 CET)
Cultural recovery of Mucorales from hyphae-laden tissue is poor, and the clinical implications of culture positivity are scarcely studied. Therefore, we compared clinical and histological characteristics of culture-positive and culture-negative histology-proven pulmonary mucormycosis cases among cancer patients. Histology specimens were blindly reviewed by a Thoracic Pathologist and graded on four histopathologic features: hyphal quantity, tissue necrosis, tissue invasion, and vascular invasion. Twenty cases with a corresponding fungal culture were identified; five were culture-positive, and 15 culture-negative. Although no statistically significant differences were found, culture-positive patients were more likely to exhibit a high burden of necrosis and have a high burden of hyphae but tended to have less vascular invasion than culture-negative patients. In terms of clinical characteristics, culture-positive patients were more likely to have acute myeloid leukemia (60% vs. 27%, p=0.19), a history of hematopoietic cell transplant (80% vs. 53%, p=0.31), severe lymphopenia (absolute lymphocyte count ≤500/µL, 100% vs. 73%, p=0.36), and monocytopenia (absolute monocyte count ≤100/µL, 60% vs. 20%, p=0.11). Forty-two-day all-cause mortality was comparable between culture-positive and culture-negative patients (60% and 53%, p=0.80). This pilot study represents the first comprehensive histopathological scoring method to examine the relationship between histopathologic features, culture positivity, and clinical features of pulmonary mucormycosis.
REVIEW | doi:10.20944/preprints202106.0437.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Corticosteroids; Glucocorticoids; Solid organ transplantation; Liver; Kidney; Heart; Lung
Online: 16 June 2021 (10:30:41 CEST)
Glucocorticoids (GCs) have been the mainstay of immunosuppressive therapy in solid organ transplantation (SOT) for decades due to their potent effects on the innate immunity and tissue protective effects. But, some SOT centers are reluctant to administer GCs for long-time due to the various side effects. This review summarizes advantages and disadvantages of GCs in SOT. PubMed and Scopus databases were searched from 2011 to April 2021 using search syntaxes cover “transplantation” and “glucocorticoids”.GCs are used in transplant recipients, transplant donors, and organ perfusate solution to improve transplant outcomes. In SOT recipients GCs are administered as induction and maintenance immunosuppressive therapy. GCs are also the cornerstone to treat acute anti-body- and T-cell-mediated rejections. Addition of GCs to organ perfusate solution and pretreatment of transplant donors with GCs are recommended by some guidelines and protocols to reduce ischemia-reperfusion injury peri-transplant. GCs with low bioavailability and high potency for GC receptors such as budesonide, nanoparticle-mediated targeted delivery of GCs to specific organs, and combination use of dexamethasone with inducers of immune-regulatory cells are new methods of GC usage in SOT patients to reduce side effects or induce immune-tolerance instead of immunosuppression. Various side effects on different non-targeted organs/tissues such as bone, cardiovascular, neuromuscular, skin, and gastrointestinal tract have been noted for GCs. There are also potential drug-drug interactions for GCs in SOT patients.
ARTICLE | doi:10.20944/preprints202105.0095.v1
Subject: Life Sciences, Biochemistry Keywords: beta cell, type 1 diabetes, islet transplantation, biomarkers, microRNA
Online: 6 May 2021 (15:01:45 CEST)
Ongoing beta cell death in type 1 diabetes (T1D) can be detected using biomarkers selectively discharged by dying beta cells into plasma. MicroRNA-375 (miR-375) ranks among top biomarkers based on studies in animal models and human islet transplantation. Our objective was to identify additional microRNAs that are co-released with miR-375 proportionate to the amount of beta cell destruction. RT-PCR profiling of 733 microRNAs in a discovery cohort of T1D patients 1 hour before/after islet transplantation indicated increased plasma levels of 22 microRNAs. Sub-selection for beta cell selectivity resulted in 15 microRNAs that were subjected to double-blinded multicenter analysis. This led to identification of 8 microRNAs that were consistently increased during early graft destruction: besides miR-375, these included miR-132/204/410/200a/429/125b, microRNAs with known function and enrichment in beta cells. Their potential clinical translation was investigated in a third independent cohort of 46 transplant patients, by correlating post-transplant microRNA levels to C-peptide levels 2 months later. Only miR-375 and miR-132 had prognostic potential for graft outcome and none of the newly identified microRNAs outperformed miR-375 in multiple regression. In conclusion, this study reveals multiple beta cell-enriched microRNAs that are co-released with miR-375 and can be used as complementary biomarkers of beta cell death.
ARTICLE | doi:10.20944/preprints202112.0332.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: faecal micromial transplantation; critically ill patiets; standard operating procedure; diarrhoea
Online: 21 December 2021 (12:50:13 CET)
Patients in intensive care unit often lose a considerable fraction of their gut microbiome due to exposure of broad-spectrum antibiotics and other reasons. Dysbiosis often results in prolonged diarrhea and increase occurrence of multi-drug resistant pathogens in the colon with clinical consequences not yet well understood. Restoring the microbioma by faecal microbial transplantation (FMT) is a plausible therapeutic possibility, so far only documented in case reports and case series using very heterogeneous methodologies. Before FMT in critically ill can be tested in randomised controlled trials, there is a burning need to describe a standardized operating procedure (SOP) of the whole process, respecting the specifics of critically ill population, such as the risk of disrubted intestinal barrier and time critical nature of the procedure. We describe the SOP that has been developed for experimental use in critically ill patients by a multidisciplinary team of intensivists, gastroenterologist and microbiologist based on feedback from regulatory authority (State Institue of Drug Control of the Czech Republic). The hallmarks of these SOPs are multi-donor freshly frozen transplantate quaranteeded for 3 months consisting of 7 aliqutes from 7 unrelated healthy donors, and administered by rectal tube. In this paper we discuss the rationale for this SOP and the process of its development in details and release the full proposed SOP is in the form of online appendix.
REVIEW | doi:10.20944/preprints202111.0087.v1
Subject: Life Sciences, Virology Keywords: virome; microbiota; cancer; bacteriophages; fecal microbiota transplantation; checkpoint inhibitors; immunotherapy
Online: 3 November 2021 (14:30:14 CET)
Viral infections as well as changes in the composition of the intestinal microbiota and virome have been linked to cancer. Moreover, the success of cancer immunotherapy with checkpoint inhibitors has been correlated with the intestinal microbial composition of patients. The transfer of feces – which contains mainly bacteria and their viruses (phages) – from immunotherapy responders to non-responders, known as fecal microbiota transplantation (FMT), has been shown to be able convert some non-responders to responders. Since phages may also increase the response to immunotherapy, for example by inducing T cells cross-reacting with cancer antigens, modulating phage populations may provide a new avenue to improve immunotherapy responsiveness. In this review, we summarize the current knowledge on the human virome and its links to cancer, and discuss the potential utility of bacteriophages in increasing the responder rate for cancer immunotherapy.
Subject: Medicine & Pharmacology, Allergology Keywords: Caveolin-1; kidney transplantation; graft rejection; ischemia; reperfusion injury (IRI)
Online: 1 December 2020 (14:08:33 CET)
Acute and chronic transplant rejections due to alloreactivity are essential contributors to graft loss. However, the strength of alloreactivity is biased by non-immunological factors such as ischemia reperfusion injury (IRI). Accordingly, protection from IRI could be favorable in terms of limiting graft rejection. Caveolin-1 (Cav-1) is part of the cell membrane and an important regulator of intracellular signaling. Cav-1 has been demonstrated to limit IRI and to promote survival of a variety of cell types including renal cells under stress conditions. Accordingly, Cav-1 could also play a role in limiting anti-graft immune responses. Here, we evaluated a possible association between pretransplant serum concentrations of Cav-1 and the occurrence of rejection during follow up in a pilot study. Therefore, Cav-1-serum concentrations were analyzed in 91 patients at the time of kidney transplantation and compared to the incidence of acute and chronic rejection. Higher Cav-1 levels were associated with lower occurrence of acute rejection episodes. Moreover, Cav-1 could be therapeutically useful for attenuating graft rejection.
ARTICLE | doi:10.20944/preprints201912.0380.v1
Subject: Medicine & Pharmacology, Urology Keywords: physical activity; kidney transplantation; elder age; vascular anomalies; marginal kidneys
Online: 29 December 2019 (11:06:25 CET)
Kidney transplantation is the treatment of choice for patients with end-stage disease. To expand the donor reserve, it is necessary to use marginal/sub optimal donors that provide marginal organs. We retrospectively evaluated the short and long-term outcome of elderly kidney transplantation using allografts with vascular abnormalities. Between January 1999 and December 2018, 740 transplants from cadaveric donors were performed. Thirty-four elderly patients received a kidney transplantation with vascular anatomical variants (Group 1) were compared with 34 patients who received a kidney transplantation with single renal artery (SRA) (Grroup2) pair-matched by age, dialysis age, donor age, comorbidity. All participants completed the Long Form International Physical Activity Questionnaire (IPAQ) at baseline and after 4, 8, and 12 weeks after transplantation. The overall rate of surgical complications was 17.6% in Group 1 and 20.6% in Group 2, indicating that kidney with vascular anatomical variant might be successfully transplanted. Our data also emphasizes the importance of individualized physical activity in kidney transplantation with multiple arteries. Physical activity should be considered as an essential part of the medical care for renal-transplanted recipients.
ARTICLE | doi:10.20944/preprints202106.0477.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Infective endocarditis; Kidney Transplantation; Survival analysis; graft failure; transplant infectious diseases
Online: 18 June 2021 (11:17:15 CEST)
Purpose: Kidney Transplant Recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation and outcome. While infective endocarditis (IE) is among such complications in KTRs, literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. Methods: We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria), in adult KTRs from January 2007 to December 2018 were included, as well as two controls per case, and followed until December 31 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan-Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Results: Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six Enterococcus spp, three Streptococcus gallolyticus and one Escherichia coli), followed by Staphylococci (three cases of S. aureus and S. epidermidis each). Among the risk factors evaluated only age was significantly associated with the occurrence of IE in our study (63.8 years for cases vs. 55.6 years for controls, P=0.03) Patient and death-censored graft survival were greatly diminished five years after IE compared to controls being 50.3% vs. 80.6% (p<0.003) and 29.7% vs. 87.5% (p<0.002), respectively. Conclusion: IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.
ARTICLE | doi:10.20944/preprints202012.0732.v1
Subject: Medicine & Pharmacology, Allergology Keywords: trace element; liver transplantation; selenoprotein P; glutathione peroxidase; hepatitis C virus
Online: 29 December 2020 (15:18:30 CET)
The trace element selenium (Se) is taken up from the diet and becomes metabolized mainly by hepatocytes. Selenoprotein P (SELENOP) constitutes the liver-derived Se transporter. Biosynthesis of extracellular glutathione peroxidase (GPx3) in kidney depends on SELENOP-mediated Se supply. We hypothesized that Se status may serve as a useful prognostic marker for outcome in patients undergoing liver transplantation. Serum samples from patients were routinely collected before and after transplantation. Concentration of serum SELENOP and total Se as well as GPx3 activity were determined by standardized tests and related to survival, aetiology and pre-operative Child-Pugh and Model for End-Stage Liver Disease Scores. A total of 314 serum samples from 78 transplanted patients were available for analysis. The Se and SELENOP concentrations were on average below the reference ranges of healthy subjects. Patients with ethanol toxicity-dependent aetiology showed particularly low SELENOP and Se concentrations and GPx3 activity. Longitudinal analysis indicated declining Se concentrations in non-survivors. We conclude that severe liver disease necessitating organ replacement is characterized by a pronounced Se deficit before, during and after transplantation. A recovering Se status after surgery is associated with positive prognosis, and an adjuvant Se supplementation may thus support convalescence.
Subject: Medicine & Pharmacology, General Medical Research Keywords: asymmetric； blasts；acute leukemia； allogeneic hematopoietic stem cell transplantation； case report
Online: 7 May 2020 (10:53:42 CEST)
Background: After allogeneic hematopoietic stem cell transplantation (allo-HSCT), acute leukemia relapse is common, and asymmetric bone marrow recurrence hasn’t been reported. Because the anatomical distribution of acute leukemia clones in the bone marrow after allo-HSCT is presumed to be diffuse, bone marrow aspirations are performed in single site. Case presentation: We identified two acute leukemia patients, whose leukemic burden in bilateral bone marrow specimens differed significantly. The first case was a 20-year-old man who was diagnosed with acute myelomonocytic leukemia and received haploidentical allo-HSCT. He had been in complete remission for two years and off immunosuppressive medications for a year, with normal peripheral blood count. Routine bone marrow biopsy of his left posterior iliac bone marrow showed 52% leukemia blasts, while the right side had 0% blasts ten days later. Due to the discordant results, the patient refused further intervention and died of high leukocyte syndrome four months later. The second case was a 23-year-old woman who was diagnosed with acute B lymphoblastic leukemia and received HLA-identical sibling allo-HSCT. Although 62% of blasts were found in her left iliac marrow on day +122, 0 % of blasts were found on a sample obtained from the right iliac crest on day +128. Whole-body 18F-FDG PET/CT scans confirmed that the leukemic infiltration in her bone marrow was asymmetric. Considering the higher leukemic burden on the left, we chose the left posterior iliac crest aspiration for further response evaluation. After chemotherapy combined with donor lymphocyte infusion, she achieved transient hematologic complete remission. She died of septic shock with heart failure at +258 days after allo-HSCT before infusion of anti-CD19 donor chimeric antigen receptor T cells. Conclusions: To our knowledge, these are the first case reports of asymmetric bone marrow infiltration of blasts in acute leukemia patients after allo-HSCT. Bilateral posterior iliac crest aspirations or 18F-FDG-PET/CT scans may help distinguish such distribution. If discordant bone marrow specimens are observed, physicians should restrict future bone marrow studies to the more involved side.
REVIEW | doi:10.20944/preprints202001.0063.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: hPSCs; hyperglycemia; insulin-secreting cells; β-cell precursors; pancreatic islets; transplantation.
Online: 8 January 2020 (05:30:34 CET)
Diabetes mellitus (DM) is one of the most prevalent metabolic disorders. In order to replace the function of the destroyed pancreatic beta cells in diabetes, islet transplantation is the widely practiced treatment; however, it has several limitations. As an alternative approach, human pluripotent stem cells (hPSCs) can provide an unlimited source of pancreatic cells that have the ability to secrete insulin in response to high blood glucose level. However, determination of the appropriate pancreatic lineage candidate for the purpose of cell therapy for treatment of diabetes is still debated upon. While hPSC-derived beta cells are perceived as the ultimate candidate, the efficiency needs further improvement in order to obtain a sufficient number of glucose responsive β-cells for transplantation therapy. On the other hand, hPSC-derived pancreatic progenitors can be efficiently generated in vitro and can further mature into glucose responsive beta cells in vivo after transplantation. Herein, we discuss the advantages and predicted challenges associated with the use of each of the two pancreatic lineage products for diabetes cell therapy. Furthermore, we address co-generation of functionally relevant islet cell subpopulations and structural properties contributing to glucose responsiveness of beta cells, as well as the available encapsulation technology for these cells.
ARTICLE | doi:10.20944/preprints201901.0137.v1
Subject: Keywords: Organ Transplantation, Ethics, Healthcare Resource Allocation, Lower Priority, Substance Use, Merit
Online: 14 January 2019 (12:05:34 CET)
Organ transplantation centers set criteria for candidate qualification, which has led to disparate healthcare resource allocation practices affecting those with a substance use history. These individuals are denied organ transplants by committees and healthcare providers who assign them lower priority status. The lower priority argument claims that healthcare resources should not be provided equally to individuals failing to share responsibility for not doing enough in addressing the diseases associated with substance use. The purpose of this work is to explore the interrelatedness between the ethics of a merit-based system of moral responsibility and lower priority setting involved in healthcare resource allocation pertaining to those with substance use histories. An integral approach to the argument against the lower prioritists with a focus on the relationship between different organ allocation practices affecting substance users and the justification for resource allocation practices in healthcare and transplant committees. Lower priority setting is challenged, and an argument offered in which substance users are assigned higher priority when relying on “doing enough” in a merit-based system of moral responsibility. It is determined that one cannot substantiate assigning a lower priority status since a lack of success in rehab does not imply a lack of effort. Additionally, neither to confirmatory behavior, nor to non-conforming behavior may freedom be justifiably ascribed in a merit-based system of responsibility because freedom to choose can neither be established a priori, nor a posteriori with respect to meritorious behavior.
ARTICLE | doi:10.20944/preprints202110.0012.v1
Subject: Medicine & Pharmacology, Other Keywords: Budd-Chiari syndrome; Living donor; Liver transplantation; Propensity score-Matched Analysis; Outcomes
Online: 1 October 2021 (11:52:48 CEST)
Introduction: There are unique technical and management challenges associated with living donor liver transplantation (LDLT) for Budd-Chiari Syndrome (BCS). The outcomes of LDLT for BCS in comparison to other indications remains unclear and warrants elucidation. Methods: Data of 24 BCS patients who underwent LDLT between January 2012 and June 2019 were analyzed. There were 20 adults and 4 children. The early and long-term outcomes of adult LDLT BCS patients were compared to a control group of LDLT patients for other indications and matched using propensity scoring methodology. Results: Primary BCS was observed in 22(91.7%) patients. Caval replacement was performed in 7(29.1%) patients. Early and late hepatic venous outflow tract (HVOT) complications were seen in 1(5.5%) and 3(16.7%) patients. Preoperative acute kidney injury was identified as a risk factor for mortality in the BCS cohort (p =0.013). On comparison, BCS recipients were younger with fewer comorbidities, more large volume ascites and higher rates of PVT. They also had longer cold ischemia time, increased blood loss and transfusion requirements, increased hospital stay, and higher late outflow complications. The 1-year and 3-year survivals were similar to non-BCS cohort (84.2% vs 94% and 70% vs 91.9%, respectively, log rank test p=0.09). Conclusion: LDLT is remains a good option for symptomatic BCS who have failed non-transplant interventions. The clinical and risk factor profile of BCS recipients is distinct from non-BCS recipients. By following an algorithmic management protocol, we show on propensity-score matched analysis that outcomes of LDLT for BCS are similar to non-BCS indications.
ARTICLE | doi:10.20944/preprints202109.0106.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: mechanical circulatory support; heart transplantation; survival curve; ventricular assist device; extracorporeal membrane oxygenation
Online: 6 September 2021 (14:39:13 CEST)
BACKGROUND: The number of waitlisted patients requiring mechanical circulatory support (MCS) as a bridge to heart transplantation is increasing. The data concerning the results of double-bridge strategy are limited. We sought to investigate the post-transplant outcomes across the different bridge strategies. METHODS: We retrospectively reviewed a heart transplantation database from Jan 2009 to Jan 2019. Intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), and ventricular assist devices (VAD) were the MCS that we investigated. The pre- and post-transplant characteristics and variables of patients bridged with the different types of MCS were collected. The post-transplant survival was compared using Kaplan-Meier survival analysis. RESULTS: A total of 251 heart transplants were reviewed; 115 without MCS and 136 with MCS. The patients were divided to five groups: Group 1 (no MCS): n=115; Group 2 (IABP): n=15; Group 3 (ECMO): n=33; Group 4 (ECMO-VAD): double-bridge (n=59); Group 5 (VAD): n=29. Survival analysis demonstrated that the 3-year post-transplant survival rates were significantly different among the groups (Log-rank p < 0.001). There was no difference in survival between group 4(ECMO-VAD) and group 1(no MCS)1 (p = 0.136), or between group 4(ECMO-VAD) and group 5(VAD) (p = 0.994). Group 3(ECMO) had significantly inferior 3-year survival than group 4(ECMO-VAD) and group 5(VAD). CONCLUSION: Double bridge may not lead to worse mid-term results in patients who could receive a transplantation. Initial stabilization with ECMO for critical patients before implantation of VAD might be considered as a strategy for obtaining an optimal post-transplant outcome.
REVIEW | doi:10.20944/preprints202209.0233.v1
Subject: Medicine & Pharmacology, Other Keywords: COVID-19 prophylaxis; COVID-19 treatment; Kidney transplantation; Vaccination; Monoclonal antibodies; Small antivirus molecules
Online: 16 September 2022 (02:00:02 CEST)
Abstract Kidney transplant recipients, because of a weak immune response due to the assumption of immunosuppressant are exposed to the risk of COVID-19 infection. This fact realize the problem on how to treat the severe infection without carrying the risk of acute rejection due to the reduction of the immunosuppressive drugs. The best are the prophylactic measures to be taken before transplantation as vaccination. If the patient is already transplanted, three measures may be undertaken: Vaccination, use of monoclonal antibodies, use of therapeutic antiviral small molecules. Concerning vaccination is still debated which one is the best and how many doses should be given. The surge of new virus variant is the major problem and invites to find new active vaccines. In addition, not all the transplanted patients develop antibodies. The other measure is the use of monoclonal antibodies. They may be used as prophylaxis or in the early stage of the disease. Finally, the antiviral small molecules may be used again as prophylaxis or treatment. Their major drawback are the interference with the immunosuppressive drugs and the fact that some of them cannot be administered to patients with low eGFR.
ARTICLE | doi:10.20944/preprints202109.0340.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: iPSC-RPE; retinal pigment epithelium; immunodeficient RCS rat; ultrathin parylene; retinal degeneration; retinal transplantation
Online: 20 September 2021 (15:31:18 CEST)
Retinal pigment epithelium (RPE) replacement therapy is evolving as a feasible approach to treat age-related macular degeneration (AMD). In majority of the preclinical studies, RPE cells are transplanted as cell suspension into immunosuppressed animal eyes and transplant effects were monitored only short-term. We investigated long-term effects of human iPSC derived RPE transplants in immunodeficient Royal College of Surgeons (RCS) rat model, in which RPE dysfunction lead to photoreceptor degeneration. iPSC-RPE cultured as polarized monolayer on nanoengineered ultrathin parylene C scaffold was transplanted into the subretinal space of 28-day old immunodeficient RCS rat pups and evaluated after 1, 4 and 11 months. Assessment at early time points showed good iPSC-RPE survival. The transplants remained as a monolayer, expressed RPE specific markers, performed phagocytic function and contributed to vision preservation. At 11-month post-implantation, RPE survival was observed only in 50% of the eyes that were concomitant with vision preservation. Loss of RPE monolayer characteristics at the 11month time point was associated with peri-membrane fibrosis, immune reaction through activation of macrophages (CD 68 expression) and transition of cell fate (expression of mesenchymal markers). The overall study outcome supports the therapeutic potential of RPE grafts despite the loss of some transplant benefits during long-term observations.
REVIEW | doi:10.20944/preprints201908.0222.v1
Subject: Materials Science, Biomaterials Keywords: Keywords: regenerative medicine; tissue engineering; decellularized extracellular matrix; 3D bioprinting; bioink, scaffolds; biofabrication; transplantation.
Online: 21 August 2019 (09:46:26 CEST)
Abstract: The promise of regenerative medicine and tissue engineering is founded on the ability to regenerate diseased or damaged tissues and organs into functional tissues and organs or the creation of new tissues and organs altogether. In theory, all damaged and diseased tissues and organs can be regenerated or created using different configurations and combinations of extracellular matrix, cells and inductive biomolecules. Currently, regenerative medicine and tissue engineering can allow the improvement of patients’ quality of life through availing novel treatment options. Tissues and organs have a specific ECM, with specific proteins and factors released by cells residing within the local microenvironment. The coupling of regenerative medicine and tissue engineering field with 3D printing is revolutionizing the treatment of patients in a huge way. 3D bioprinting allows the proper placement of cells and ECMs, allowing the recapitulation of native microenvironments of tissues and organs. 3D bioprinting utilizes different bioinks made up of different formulations of ECM/biomaterials, biomolecules and even cells. The choice of the bioink used during 3D bioprinting is very important as properties such as printability, compatibility and physical strength influence the final construct printed. The extracellular matrix (ECM) provides both physical and mechanical microenvironment needed by cells to survive and proliferate. Decellularized ECM bioink contains biochemical cues from the original native ECM and also the right proportions of ECM proteins. Different techniques and characterization methods are used to derive bioinks from several tissues and organs and to evaluate their quality. This review discusses the uses of decellularized ECM bioinks and argues that they represent the most biomimetic bioinks available. In addition, we briefly discuss some polymer-based bioinks utilized in 3D bioprinting.
REVIEW | doi:10.20944/preprints201802.0101.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: spleen; islet transplantation; transplant site; immunity; tolerance; regeneration; diabetes mellitus; mesenchymal stem cell; Sjogren’s syndrome; HOX
Online: 2 April 2018 (11:05:40 CEST)
In this review, we show the unique potential of spleen as an optimal site for islet transplantation and a source of mesenchymal stem cells. Islet transplantation is a cellular replacement therapy to treat severe diabetes mellitus, but its clinical outcome is unsatisfactory at present. One factor in clinical success of this therapy is selection of the most appropriate transplantation site. The spleen has been studied for a long time as a candidate site for islet transplantation. Its advantages include physiological insulin drainage and regulation of immunity. Recently it has also been shown that the spleen contributes to the regeneration of transplanted islets. The efficacy of transplantation is not as high as that obtained with intraportal transplantation, which is the current representative method of clinical islet transplantation. Safer and more effective methods of islet transplantation need to be established before the spleen can be effectively used in the clinic. Spleen also has an interesting aspect as a mesenchymal stem cell reservoir. The splenic mesenchymal stem cells contribute to tissue repair in damaged tissue, and thus, the infusion can be a promising therapy for autoimmune diseases, including type 1 diabetes mellitus and Sjogren’s syndrome.
CASE REPORT | doi:10.20944/preprints202209.0161.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: Antibody-mediated rejection; Crossmatch; Daratumumab; End-stage renal disease; Flow cytometry; HLA; Multiple myeloma; Transplantation
Online: 13 September 2022 (05:48:27 CEST)
We report the first case of Daratumumab interference of allogeneic crossmatch tests repeatedly causing aberrant false-positive results, which inadvertently delayed transplant for a waitlisted renal patient with multiple myeloma. Daratumumab is an IgG1κ human monoclonal antibody commonly used to treat multiple myeloma, characterized by cancerous plasma cells and often leads to renal failure requiring kidney transplant, by depleting CD38-expressing plasma cells. In this case study, the patient had end-stage renal disease secondary to multiple myeloma and was continuously receiving Daratumumab infusions. The patient did not have any detectable antibodies to human leukocyte antigens but repeatedly had unexpected positive crossmatch by the flow cytometry-based method with 26 of the 27 potential deceased organ donors, implying donor-recipient immunological incompatibility. However, further review and analysis suggested that the positive crossmatches were likely false-positive as a result of interference from Daratumumab binding to donor cell surface CD38 as opposed to the presence of donor-specific antibodies. The observed intensity of the false-positive crossmatches was also highly variable, potentially due to donor- and/or cell-dependent expression of CD38. The variability of CD38 expression was, therefore, for the first time, characterized on the T and B cells isolated from various tissues and peripheral blood of 78 individuals. Overall, T cells were found to have a lower CD38 expression profile than the B cells, and no significant difference was observed between deceased and living individuals. Finally, we show that a simple cell treatment by dithiothreitol can effectively mitigate Daratumumab interference thus preserving the utility of pre-transplant crossmatch in multiple myeloma patients awaiting kidney transplant.
REVIEW | doi:10.20944/preprints202011.0268.v1
Subject: Life Sciences, Biochemistry Keywords: Keywords Exercise; osteoarthritis; osteoporosis; mesenchymal stem cells; hematopoietic stem cells; stem cell transplantation; chondroblasts; chondrocytes; cytokines.
Online: 9 November 2020 (10:00:10 CET)
Abstract: This article provides a brief review of the ontogeny of chondrocytes and the pathophysiology of osteoarthritis (OA), and details how physical exercise improves the health of osteoarthritic joints and enhances the potential of mesenchymal stem cells for successful transplantation therapy. In response to exercise chondrocytes increase their production of glycosaminoglycans, bone morphogenic proteins and antiinflammatory cytokines and decrease their production of proinflammatory cytokines and matrix degrading metalloproteinases. These changes are associated with improvements in cartilage organization and reductions in cartilage degeneration. Studies in humans indicate that exercise increases peripheral blood recruitment of bone marrow-derived mesenchymal stem cells (BM-MSC) and upregulates BM-MSC expression of osteogenic and chondrogenic genes, osteogenic micro-RNAs, and osteogenic growth factors. Rodent experiments are uniform in demonstrating that exercise enhances the osteogenic potential of BM-MSC while diminishing their adipogenic potential, and that exercise done after stem cell implantation may benefit stem cell transplant viability. Physical exercise also exerts a beneficial effect on the skeletal system by decreasing immune cell production of osteoclastogenic cytokines interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and interferon (INF)-γ while increasing their production anti-osteoclastogenic cytokines IL-10 and transforming growth factor (TGF)-β. In conclusion, physical exercise done both by stem cell donors and recipients may improve the outcome of mesenchymal stem cell transplantation.
REVIEW | doi:10.20944/preprints202008.0557.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: transplantation; dental implant; marginal bone loss; implant failure rate; systematic review; periodontitis; periodontal diseases; oral health
Online: 25 August 2020 (13:45:34 CEST)
This systematic review investigates the failure rate and marginal bone loss (MBL) of dental implants placed in Solid-organ transplant (SOT) patients compared to healthy controls. Three databases (PubMed, Web of Sciences and the Cochrane Library) were searched up to June 2020 (PROSPERO CRD42019124896). Case-control and cohort studies reporting data failure rate and marginal bone loss (MBL) of dental implants placed in SOT patients were included. The risk of bias of observational studies was assessed through the Newcastle-Ottawa Scale (NOS). Four case-control studies fulfilled the inclusion criteria, all of low risk of bias. Meta-analyses revealed consistently lower implant failure rate than control populations at patient and implant levels. SOT patients had a significant difference of -18% (p-value <0.001) of MLB towards healthy patients. SOT status poses no serious threat to implant survival. Overall, this group of patients presented lower levels of dental implant failure rate and marginal bone loss compared to otherwise healthy patients. Further intervention trials with wider sample size and longer follow-ups are necessary to confirm these summary results.
ARTICLE | doi:10.20944/preprints201811.0454.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: perioperative goal-directed fluid therapy; haemodynamics monitoring; fluid management; kidney transplantation; major postoperative complications; outcome of surgery
Online: 19 November 2018 (10:57:00 CET)
Background: Kidney transplantation is considered the first-choice therapy in ESRD patients. Despite recent improvements in terms of outcomes and graft survival in recipients, postoperative complications still concern health-care providers involved in the management of those patients. Particularly challenging are cardiovascular complications. Perioperative goal-directed fluid-therapy (PGDT) and hemodynamic optimization are widely used in high-risk surgical patients, and are associated with a significant reduction in postoperative complication rates and length of stay (LOS). The aim of this work is to compare the effects of perioperative goal-directed therapy (PGDT) with conventional fluid therapy (CFT), and to determine whether there are any differences in major postoperative complications rates and delayed graft function (DGF) outcomes. Methods: Prospective study with historical controls. Two groups, a PGDT- and a CFT- group were used: the stroke volume (SV) optimization protocol was applied in PGDT group throughout the procedure. Conventional fluid therapy with fluids titration at a central venous pressure (CVP) 8-12 mmHg and mean arterial pressure (MAP) >80mmHg was applied to the control-group. Postoperative data collection including vital signs, weight, urinary output, serum creatinine, blood urea nitrogen, serum potassium, and assessement of volemic status and the signs and symptoms of major postoperative complications occurred at 24h, 72h, 7 days and 30 days after transplantation. Results: Among the 66 patients enrolled, 33 were in each group and both groups had similar physical characteristics. Good fuctional recovery was evident in the 94% of patients. The statistical analysis has showed a difference in postoperative complications as follows: significant reduction of cardiovascular complications, DGF episodes (p<0.05) and surgical complications (p<0.01). There were no significant differences in pulmonary or other complication. Conclusions: PGDT and SV optimization effectively influenced the rate of major postoperative complications, reducing the overall morbidity and thus the mortality in patients receiving kidney transplantation.
REVIEW | doi:10.20944/preprints201911.0013.v1
Subject: Medicine & Pharmacology, Other Keywords: lung transplantation; body mass index; nutrition; body composition; lean body mass; muscle mass; leptin; sarcopenia; creatinine-height index
Online: 1 November 2019 (13:02:51 CET)
Lung transplantation offers patients with end stage lung disease an opportunity for a better quality of life, but with limited organ availability it is paramount that selected patients have the best opportunity for successful outcomes. Nutrition plays a central role in post-surgical outcomes and historically, body mass index (BMI) has been used as the de facto method of assessing a lung transplant candidate’s nutritional status. Here we review the historical origins of BMI in lung transplantation, summarize the current BMI literature, and review studies of alternative/complementary body composition assessment tools, including lean psoas area, creatinine-height index, leptin, and dual x-ray absorptometry. These body composition measures quantify lean body mass versus fat mass and may provide a more comprehensive analysis of a patient’s nutritional state than BMI alone.
ARTICLE | doi:10.20944/preprints201810.0321.v1
Subject: Keywords: amniotic membrane; epithelialization; inflammation; ocular surface disorders; anti-fibrotic action, amniotic membrane eye drop, amniotic membrane graft transplantation
Online: 15 October 2018 (14:35:06 CEST)
The aim of this study is to emphasize on the clinical uses of amniotic membrane (AM) in multiple ocular disorders. AM possesses many properties including promotion of epithelialization, anti-fibrotic, anti-apoptotic, anti-angiogenic properties. Epithelial wound healing on the eye surface is promoted due to several epidermal and keratocyte growth factors as well as by its anti-inflammatory and anti-scarring effects due to interleukin-10, interleukin-1 receptor antagonists and inhibition of transforming growth factor- beta (TGF-β) signal transduction by AM in the corneal and conjunctival fibroblasts respectively. It plays a crucial role by functioning as a substitute of basement membrane (BM) and as a temporary graft material. It is not only being used as an eye graft but also its extract can be used as an eye drop for corneal and external eye diseases. So its proper preparation, preservation and clinical application can bring a revolutionary change in the treatment of different ocular disorders.
REVIEW | doi:10.20944/preprints201810.0307.v1
Subject: Medicine & Pharmacology, Ophthalmology Keywords: Keywords: amniotic membrane; epithelialization; inflammation; ocular surface disorders; anti-fibrotic action, amniotic membrane eye drop, amniotic membrane graft transplantation.
Online: 15 October 2018 (12:06:21 CEST)
Abstract: The aim of this study is to emphasize on the clinical uses of amniotic membrane (AM) in multiple ocular disorders. AM possesses many properties including promotion of epithelialization, anti-fibrotic, anti-apoptotic, anti-angiogenic properties. Epithelial wound healing on the eye surface is promoted due to several epidermal and keratocyte growth factors as well as by its anti-inflammatory and anti-scarring effects due to interleukin-10, interleukin-1 receptor antagonists and inhibition of transforming growth factor- beta (TGF-β) signal transduction by AM in the corneal and conjunctival fibroblasts respectively. It plays a crucial role by functioning as a substitute of basement membrane (BM) and as a temporary graft material. It is not only being used as an eye graft but also its extract can be used as an eye drop for corneal and external eye diseases. So its proper preparation, preservation and clinical application can bring a revolutionary change in the treatment of different ocular disorders.
REVIEW | doi:10.20944/preprints202103.0373.v1
Subject: Life Sciences, Biochemistry Keywords: Mesenchymal stem/stromal cells; regenerative medicine; tissue engineering; Clinical Application; Differentiation Capacity; Cellular Immunomodulation; Inflammation; Signaling Cells; Transplantation; International Society for Cell and Gene Therapy
Online: 15 March 2021 (11:51:28 CET)
Early reports demonstrated the presence of cells with stem-like properties in bone marrow, with these cells having both hematopoietic and mesenchymal lineages. Over the years, various investigations have purified and characterized mesenchymal stromal/stem cells (MSCs) from different human tissues as cells with multi-lineage differentiation potential under the appropriate conditions. Due to their appealing characteristics and potential, MSCs are leveraged in many applications including medicine, oncology, bioprinting and as recent as treatment of COVID-19. To date, reports indicate mesenchymal stromal/stem cells have varied differentiation capabilities into different cell types and demonstrate immunomodulating and anti-inflammatory properties. Reports indicate that different MSCs microenvironments or niche and the resulting heterogeneity may influence their behavior and differentiation capacity. The potential clinical applications of mesenchymal stromal/stem cells have led to an avalanche of research reports on their properties and hundreds of clinical trials being undertaken. The future looks bright and promising for mesenchymal stem cell research with many clinical trials under way to prove their utility in many applications and in the clinic. This report provides an update on the potential broader use of mesenchymal stromal/stem cells, review early observations of the presence of these cells in the bone marrow and their magnificent differentiation capabilities and immunomodulation.
CASE REPORT | doi:10.20944/preprints201810.0491.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: cytomegalovirus (CMV); infection, reactivation, epidemiology, host-virus interaction, CMV-specific IgG; protective IgG level, avidity, adoptive/acquired immune response, hematopoietic stem cell transplantation (HSCT); secondary immunodeficiency, Quantiferon, pentamer, β2-microglobulin/beta 2-Microglobulin
Online: 22 October 2018 (11:53:47 CEST)
Although the existing paradigm states that CMV reactivation is under control of cellular immune response, the role of humoral counterpart is underestimated. Anti-CMV positive woman after conditioning with Bu-Flu-ATG underwent stem cell transplantation from fully matched, seronegative sibling donor. In immunodeficient recipient fast and significant decrease of specific immune response was observed but reconstitution of marrow-derived B and NK cells was prior thymic origin T cells. The lowest CMV-IgG(89 U/ml) was observed just before CMV viremia. Noteworthy, the sole and exclusive factor of CMV-specific immune response is a residual recipient antibody class IgG. The CMV-quantiferon increase was observed later, but in the first phase immune reconstitution of the PHA-induced IFNγ release was significantly lower than that CMV-induced. It corresponds with NK cells increase at the top of lymphocyte reconstitution and undetected CMV-specific CD8 cells by pentamer technique. Most of NK cells are CD16+, thus are stimulated by residual IgG. In immunocompetent donor the cellular and humoral immune response increases in parallel manner but symptoms of CMV mononucleosis were observed till the increase of specific IgG. Our observations shed light on a unique host-CMV interaction: indicate that significant decrease of CMV-IgG is a good predictor for CMV reactivation during secondary immunodeficiency.
REVIEW | doi:10.20944/preprints202010.0578.v1
Subject: Biology, Anatomy & Morphology Keywords: Type 1 diabetes; insulin therapy; C-peptide; islet transplantation, mesenchymal stem cells; induced pluripotent stem cells; pancreatic β cell; gene therapy; β-cell regeneration and reprogramming, type 1 diabetes precision medicine, diabetes personalized care.
Online: 28 October 2020 (10:02:34 CET)
Type 1 diabetes affects millions of people globally and requires careful management to avoid serious long-term complications, including heart and kidney disease, stroke, and loss of sight. The present standard-of-care for type 1 diabetes is exogenic insulin substitutional therapy. The most advanced stretegies in this area is the development of hybrid-closed loop system and the producing of long-acting insulins. Progresses in stem cell therapies have started to revolutionize the care of patients with type 1 diabetes; however, significant challenges remain including the limited islets availability, difficulties in maintaining the viability, the heterogeneity within a complex pathology and in patients’ responses to treatment. On the way, a considerable amount of efforts in maximizing the islet transplantation effectiveness by controlling the advantageous of different stem cell approaches. With the availability and the use of big data, the concept of precision medicine is gaining wide attention worldwide and could bring the dream of “presonlaized” therapies as a reality in the near future. Here we review the current range of treatments available as well as recent pre-clinical breakthroughs in the field of personlaized medicine for type 1 diabetes.