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1.
Transpl Int ; 37: 12475, 2024.
Article in English | MEDLINE | ID: mdl-38665475

ABSTRACT

An increasing number of sensitized patients awaiting transplantation face limited options, leading to fatalities during dialysis and higher costs. The absence of established evidence highlights the need for collaborative consensus. Donor-specific antibodies (DSA)-triggered antibody-mediated rejection (AMR) significantly contributes to kidney graft failure, especially in sensitized patients. The European Society for Organ Transplantation (ESOT) launched the ENGAGE initiative, categorizing sensitized candidates by AMR risk to improve patient care. A systematic review assessed induction and maintenance regimens as well as antibody removal strategies, with statements subjected to the Delphi methodology. A Likert-scale survey was distributed to 53 European experts (Nephrologists, Transplant surgeons and Immunologists) with experience in kidney transplant recipient care. A rate ≥75% with the same answer was considered consensus. Consensus was achieved in 95.3% of statements. While most recommendations aligned, two statements related to complement inhibitors for AMR prophylaxis lacked consensus. The ENGAGE consensus presents contemporary recommendations for desensitization and immunomodulation strategies, grounded in predefined risk categories. The adoption of tailored, patient-specific measures is anticipated to streamline the care of sensitized recipients undergoing renal allografts. While this approach holds the promise of enhancing transplant accessibility and fostering long-term success in transplantation outcomes, its efficacy will need to be assessed through dedicated studies.


Subject(s)
Consensus , Delphi Technique , Graft Rejection , Kidney Transplantation , Humans , Graft Rejection/prevention & control , Graft Rejection/immunology , Europe , Isoantibodies/immunology , Transplant Recipients
2.
Curr Opin Organ Transplant ; 29(3): 205-211, 2024 06 01.
Article in English | MEDLINE | ID: mdl-38529696

ABSTRACT

PURPOSE OF REVIEW: In recent years, the xenotransplantation science has advanced tremendously, with significant strides in both preclinical and clinical research. This review intends to describe the latest cutting-edge progress in knowledge and methodologies developed to overcome potential obstacles that may preclude the translation and successful application of clinical xenotransplantation. RECENT FINDINGS: Preclinical studies have demonstrated that it is now possible to extend beyond two years survival of primate recipients of life saving xenografts. This has been accomplished thanks to the utilization of genetic engineering methodologies that have allowed the generation of specifically designed gene-edited pigs, a careful donor and recipient selection, and appropriate immunosuppressive strategies.In this light, the compassionate use of genetically modified pig hearts has been authorized in two human recipients and xenotransplants have also been achieved in human decedents. Although encouraging the preliminary results suggest that several challenges have yet to be fully addressed for a successful clinical translation of xenotransplantation. These challenges include immunologic, physiologic and biosafety aspects. SUMMARY: Recent progress has paved the way for the initial compassionate use of pig organs in humans and sets the scene for a wider application of clinical xenotransplantation.


Subject(s)
Graft Rejection , Transplantation, Heterologous , Animals , Humans , Animals, Genetically Modified , Graft Rejection/immunology , Graft Rejection/prevention & control , Graft Survival , Heterografts , Immunosuppressive Agents/therapeutic use , Immunosuppressive Agents/adverse effects , Swine , Treatment Outcome
3.
Am J Transplant ; 23(9): 1290-1299, 2023 09.
Article in English | MEDLINE | ID: mdl-37217005

ABSTRACT

In June 2022, the US Food and Drug Administration Center for Biologics Evaluation and Research held the 73rd meeting of the Cellular, Tissue, and Gene Therapies Advisory Committee for public discussion of regulatory expectations for xenotransplantation products. The members of a joint American Society of Transplant Surgeons/American Society of Transplantation committee on xenotransplantation compiled a meeting summary focusing on 7 topics believed to be key by the committee: (1) preclinical evidence supporting progression to a clinical trial, (2) porcine kidney function, (3) ethical aspects, (4) design of initial clinical trials, (5) infectious disease issues, (6) industry perspectives, and (7) regulatory oversight.


Subject(s)
Motivation , Surgeons , United States , Animals , Swine , Humans , Transplantation, Heterologous , United States Food and Drug Administration
4.
Transpl Int ; 36: 11321, 2023.
Article in English | MEDLINE | ID: mdl-37560072

ABSTRACT

Solid phase immunoassays improved the detection and determination of the antigen-specificity of donor-specific antibodies (DSA) to human leukocyte antigens (HLA). The widespread use of SPI in kidney transplantation also introduced new clinical dilemmas, such as whether patients should be monitored for DSA pre- or post-transplantation. Pretransplant screening through SPI has become standard practice and DSA are readily determined in case of suspected rejection. However, DSA monitoring in recipients with stable graft function has not been universally established as standard of care. This may be related to uncertainty regarding the clinical utility of DSA monitoring as a screening tool. This consensus report aims to appraise the clinical utility of DSA monitoring in recipients without overt signs of graft dysfunction, using the Wilson & Junger criteria for assessing the validity of a screening practice. To assess the evidence on DSA monitoring, the European Society for Organ Transplantation (ESOT) convened a dedicated workgroup, comprised of experts in transplantation nephrology and immunology, to review relevant literature. Guidelines and statements were developed during a consensus conference by Delphi methodology that took place in person in November 2022 in Prague. The findings and recommendations of the workgroup on subclinical DSA monitoring are presented in this article.


Subject(s)
Kidney Transplantation , Organ Transplantation , Humans , Graft Rejection , Isoantibodies , Kidney , HLA Antigens , Graft Survival , Transplant Recipients , Tissue Donors , Histocompatibility Testing , Retrospective Studies
5.
Transpl Int ; 36: 11498, 2023.
Article in English | MEDLINE | ID: mdl-37767527

ABSTRACT

The primary aim of this study was to describe regulations and practices concerning the family approach to discuss donation, specifically after the neurological determination of death, one of the most challenging steps in the donation pathway. A secondary objective was to assess the impact of legislation on consent rates for organ donation. The Council of Europe surveyed 39 member states about national regulations, practices, and consent rates; 34 replied. Opt-out legislation is present in 19, opt-in in 9 and a mixed system in six countries. An opt-out register is kept by 24 countries and an opt-in register by 18 countries, some keeping both. The mean consent rate was 81.2% of all family approaches. Most countries regulate how death using neurological criteria is confirmed (85.3%), while regulation of other aspects of the deceased donation pathway varies: the timing of informing the family about brain death (47.1%) and organ donation (58.8%), the profile of professional who discusses both topics with the family (52.9% and 64.7%, respectively) and the withdrawal of treatment after brain death (47.1%). We also noted a mismatch between what regulations state and what is done in practice in most countries. We suggest possible reasons for this disparity.


Subject(s)
Organ Transplantation , Tissue and Organ Procurement , Humans , Brain Death , Tissue Donors , Europe
6.
Brain ; 145(5): 1584-1597, 2022 06 03.
Article in English | MEDLINE | ID: mdl-35262656

ABSTRACT

There has been substantial progress in the development of regenerative medicine strategies for CNS disorders over the last decade, with progression to early clinical studies for some conditions. However, there are multiple challenges along the translational pipeline, many of which are common across diseases and pertinent to multiple donor cell types. These include defining the point at which the preclinical data are sufficiently compelling to permit progression to the first clinical studies; scaling-up, characterization, quality control and validation of the cell product; design, validation and approval of the surgical device; and operative procedures for safe and effective delivery of cell product to the brain. Furthermore, clinical trials that incorporate principles of efficient design and disease-specific outcomes are urgently needed (particularly for those undertaken in rare diseases, where relatively small cohorts are an additional limiting factor), and all processes must be adaptable in a dynamic regulatory environment. Here we set out the challenges associated with the clinical translation of cell therapy, using Huntington's disease as a specific example, and suggest potential strategies to address these challenges. Huntington's disease presents a clear unmet need, but, importantly, it is an autosomal dominant condition with a readily available gene test, full genetic penetrance and a wide range of associated animal models, which together mean that it is a powerful condition in which to develop principles and test experimental therapeutics. We propose that solving these challenges in Huntington's disease would provide a road map for many other neurological conditions. This white paper represents a consensus opinion emerging from a series of meetings of the international translational platforms Stem Cells for Huntington's Disease and the European Huntington's Disease Network Advanced Therapies Working Group, established to identify the challenges of cell therapy, share experience, develop guidance and highlight future directions, with the aim to expedite progress towards therapies for clinical benefit in Huntington's disease.


Subject(s)
Huntington Disease , Neurodegenerative Diseases , Animals , Brain/metabolism , Cell- and Tissue-Based Therapy , Humans , Huntington Disease/genetics , Huntington Disease/metabolism , Huntington Disease/therapy , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/therapy
7.
Eur J Immunol ; 51(6): 1412-1422, 2021 06.
Article in English | MEDLINE | ID: mdl-33576494

ABSTRACT

Heterologous polyclonal antibodies might represent an alternative to the use of convalescent plasma or monoclonal antibodies (mAbs) in coronavirus disease (COVID-19) by targeting multiple antigen epitopes. However, heterologous antibodies trigger human natural xenogeneic antibody responses particularly directed against animal-type carbohydrates, mainly the N-glycolyl form of the neuraminic acid (Neu5Gc) and the α1,3-galactose, potentially leading to serum sickness or allergy. Here, we immunized cytidine monophosphate-N-acetylneuraminic acid hydroxylase and α1,3-galactosyl-transferase (GGTA1) double KO pigs with the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor binding domain to produce glyco-humanized polyclonal neutralizing antibodies lacking Neu5Gc and α1,3-galactose epitopes. Animals rapidly developed a hyperimmune response with anti-SARS-CoV-2 end-titers binding dilutions over one to a million and end-titers neutralizing dilutions of 1:10 000. The IgG fraction purified and formulated following clinical Good Manufacturing Practices, named XAV-19, neutralized spike/angiotensin converting enzyme-2 interaction at a concentration <1 µg/mL, and inhibited infection of human cells by SARS-CoV-2 in cytopathic assays. We also found that pig GH-pAb Fc domains fail to interact with human Fc receptors, thereby avoiding macrophage-dependent exacerbated inflammatory responses and a possible antibody-dependent enhancement. These data and the accumulating safety advantages of using GH-pAbs in humans warrant clinical assessment of XAV-19 against COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19/therapy , SARS-CoV-2/immunology , Animals , Animals, Genetically Modified/genetics , Animals, Genetically Modified/immunology , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/pharmacology , Antibodies, Viral/genetics , Antibodies, Viral/pharmacology , COVID-19/genetics , Galactosyltransferases/deficiency , Galactosyltransferases/immunology , HEK293 Cells , Humans , Immunization, Passive , SARS-CoV-2/genetics , Sialic Acids/genetics , Sialic Acids/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Swine , COVID-19 Serotherapy
8.
J Pathol ; 254(2): 173-184, 2021 06.
Article in English | MEDLINE | ID: mdl-33626204

ABSTRACT

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pneumopathy is characterized by a complex clinical picture and heterogeneous pathological lesions, both involving alveolar and vascular components. The severity and distribution of morphological lesions associated with SARS-CoV-2 and how they relate to clinical, laboratory, and radiological data have not yet been studied systematically. The main goals of the present study were to objectively identify pathological phenotypes and factors that, in addition to SARS-CoV-2, may influence their occurrence. Lungs from 26 patients who died from SARS-CoV-2 acute respiratory failure were comprehensively analysed. Robust machine learning techniques were implemented to obtain a global pathological score to distinguish phenotypes with prevalent vascular or alveolar injury. The score was then analysed to assess its possible correlation with clinical, laboratory, radiological, and tissue viral data. Furthermore, an exploratory random forest algorithm was developed to identify the most discriminative clinical characteristics at hospital admission that might predict pathological phenotypes of SARS-CoV-2. Vascular injury phenotype was observed in most cases being consistently present as pure form or in combination with alveolar injury. Phenotypes with more severe alveolar injury showed significantly more frequent tracheal intubation; longer invasive mechanical ventilation, illness duration, intensive care unit or hospital ward stay; and lower tissue viral quantity (p < 0.001). Furthermore, in this phenotype, superimposed infections, tumours, and aspiration pneumonia were also more frequent (p < 0.001). Random forest algorithm identified some clinical features at admission (body mass index, white blood cells, D-dimer, lymphocyte and platelet counts, fever, respiratory rate, and PaCO2 ) to stratify patients into different clinical clusters and potential pathological phenotypes (a web-app for score assessment has also been developed; https://r-ubesp.dctv.unipd.it/shiny/AVI-Score/). In SARS-CoV-2 positive patients, alveolar injury is often associated with other factors in addition to viral infection. Identifying phenotypical patterns at admission may enable a better stratification of patients, ultimately favouring the most appropriate management. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Subject(s)
COVID-19/diagnosis , COVID-19/virology , Machine Learning , Respiratory Distress Syndrome/etiology , SARS-CoV-2/pathogenicity , Vascular System Injuries/etiology , Aged , Aged, 80 and over , Female , Humans , Male , Respiratory Distress Syndrome/diagnosis , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/virology , Vascular System Injuries/diagnosis , Vascular System Injuries/virology
9.
Transpl Int ; 35: 10322, 2022.
Article in English | MEDLINE | ID: mdl-35928348

ABSTRACT

Discrepancies in donation and transplantation by sex and gender have previously been reported. However, whether such differences are invariably the inevitable, unintended outcome of a legitimate process has yet to be determined. The European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) is the committee that actively promotes the development of ethical, quality and safety standards in the field of transplantation in Europe. Whilst the ultimate objective is to shed light on the processes underlying potential gender inequities in transplantation, our initial goal was to represent the distribution by sex among organ donors and recipients in the CD-P-TO Member States and observer countries. Our survey confirms previous evidence that, in most countries, men represent the prevalent source of deceased donors (63.3% in 64 countries: 60.7% and 71.9% for donation after brain and circulatory death, respectively). In contrast, women represent the leading source of organs recovered from living kidney and liver donors (61.1% and 51.2% in 55 and 32 countries, respectively). Across countries, most recovered organs are transplanted into men (65% in 57 countries). These observations may be explained, at least in part, by the higher burden of certain diseases in men, childbearing related immune sensitization in women, and donor-recipient size mismatch. Future research should establish whether gender-related socially-constructed roles and socioeconomic status may play a detrimental role reducing the access of women to transplantation.


Subject(s)
Kidney Transplantation , Organ Transplantation , Tissue and Organ Procurement , Europe , Female , Humans , Male , Surveys and Questionnaires , Tissue Donors
10.
Transpl Int ; 34(11): 2006-2018, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34459040

ABSTRACT

The future clinical application of animal-to-human transplantation (xenotransplantation) is of importance to society as a whole. Favourable preclinical data relevant to cell, tissue and solid organ xenotransplants have been obtained from many animal models utilizing genetic engineering and protocols of pathogen-free husbandry. Findings have reached a tipping point, and xenotransplantation of solid organs is approaching clinical evaluation, the process of which now requires close deliberation. Such discussions include considering when there is sufficient evidence from preclinical animal studies to start first-in-human xenotransplantation trials. The present article is based on evidence and opinions formulated by members of the European Society for Organ Transplantation who are involved in the Transplantation Learning Journey project. The article includes a brief overview of preclinical concepts and biology of solid organ xenotransplantation, discusses the selection of candidates for first-in-human studies and considers requirements for study design and conduct. In addition, the paper emphasizes the need for a regulatory framework for xenotransplantation of solid organs and the essential requirement for input from public and patient stakeholders.


Subject(s)
Organ Transplantation , Transplants , Animals , Heterografts , Humans , Models, Animal , Transplantation, Heterologous
11.
Transpl Int ; 34(3): 488-498, 2021 03.
Article in English | MEDLINE | ID: mdl-33423340

ABSTRACT

The Banff antibody-mediated rejection (ABMR) classification is vulnerable to misinterpretation, but the reasons are unclear. To better understand this vulnerability, we evaluated how ABMR is diagnosed in practice. To do this, the Banff Antibody-Mediated Injury Workgroup electronically surveyed an international cohort of nephrologists/surgeons (n = 133) and renal pathologists (n = 99). Most providers (97%) responded that they use the Banff ABMR classification at least sometimes, but DSA information is often not readily available. Only 41.1% (55/133) of nephrologists/surgeons and 19.2% (19/99) of pathologists reported that they always have DSA results when the biopsy is available. Additionally, only 19.6% (26/133) of nephrologists/surgeons responded that non-HLA antibody or molecular transcripts are obtained when ABMR histologic features are present but DSA is undetected. Several respondents agreed that histologic features concerning for ABMR in the absence of DSA and/or C4d are not well accounted for in the current classification [31.3% (31/99) pathologists and 37.6% (50/133) nephrologist/surgeons]. The Banff ABMR classification appears widely accepted, but efforts to improve the accessibility of DSA information for the multidisciplinary care team are needed. Further clarity is also needed in Banff ABMR nomenclature to account for the spectrum of ABMR and for histologic features suspicious for ABMR when DSA is absent.


Subject(s)
Kidney Transplantation , Allografts , Cohort Studies , Graft Rejection/diagnosis , Humans , Isoantibodies , Kidney Transplantation/adverse effects
12.
Transpl Int ; 34(11): 2112-2121, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34553794

ABSTRACT

The access of non-resident patients to the deceased donor waiting list (DDWL) poses different challenges. The European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) has studied this phenomenon in the European setting. A questionnaire was circulated among the Council of Europe member states to inquire about the criteria applied for non-residents to access their DDWL. Information was compiled from 28 countries. Less than 1% of recipients of deceased donor organs were non-residents. Two countries never allow non-residents to access the DDWL, four allow access without restrictions and 22 only under specific conditions. Of those, most give access to non-resident patients already in their jurisdictions who are in a situation of vulnerability (urgent life-threatening conditions). In addition, patients may be given access: (i) after assessment by a specific committee (four countries); (ii) within the framework of official cooperation agreements (15 countries); and (iii) after patients have officially lived in the country for a minimum length of time (eight countries). The ethical and legal implications of these policies are discussed. Countries should collect accurate information about residency status of waitlisted patients. Transparent criteria for the access of non-residents to DDWL should be clearly defined at national level.


Subject(s)
Kidney Transplantation , Organ Transplantation , Tissue and Organ Procurement , Europe , Humans , Tissue Donors , Waiting Lists
13.
Am J Transplant ; 20(10): 2933-2937, 2020 10.
Article in English | MEDLINE | ID: mdl-32400074

ABSTRACT

Coronavirus disease 2019 (COVID-19) has been declared pandemic since March 2020. In Europe, Italy was the first nation affected by this infection. We report anamnestic data, clinical features, and therapeutic management of 2 lung transplant recipients with confirmed COVID-19 pneumonia. Both patients were in good clinical condition before the infection and were receiving immunosuppression with calcineurin inhibitors (CNI), mycophenolate mofetil, and corticosteroids. Whereas mycophenolate mofetil was withdrawn in both cases, CNI were suspended only in the second patient. The first patient always maintained excellent oxygen saturation throughout hospitalization with no need for additional oxygen therapy. He was discharged with a satisfactory pulmonary function and a complete resolution of radiological and clinical findings. However, at discharge SARS-CoV-2 RNA could still be detected in the nasopharyngeal swab and in the stools. The second patient required mechanical ventilation, had a progressive deterioration of his clinical conditions, and had a fatal outcome. Further insight into SARS-CoV-2 infection is eagerly awaited to improve the outcome of transplant recipients affected by COVID-19 pneumonia.


Subject(s)
Betacoronavirus , Coronavirus Infections/diagnosis , Lung Transplantation/methods , Pneumonia, Viral/diagnosis , Transplant Recipients , Aged , COVID-19 , Coronavirus Infections/therapy , Coronavirus Infections/transmission , Cystic Fibrosis/surgery , Humans , Immunosuppressive Agents/therapeutic use , Male , Middle Aged , Pandemics , Pneumonia, Viral/therapy , Pneumonia, Viral/transmission , Postoperative Period , Pulmonary Disease, Chronic Obstructive/surgery , Respiration, Artificial , SARS-CoV-2 , Tomography, X-Ray Computed
14.
BMC Med ; 18(1): 262, 2020 09 23.
Article in English | MEDLINE | ID: mdl-32962714

ABSTRACT

BACKGROUND: High consumption of red and processed meat is commonly associated with increased cancer risk, particularly colorectal cancer. Antibodies against the red meat-derived carbohydrate N-glycolylneuraminic acid (Neu5Gc) exacerbate cancer in "human-like" mice. Human anti-Neu5Gc IgG and red meat are both independently proposed to increase cancer risk, yet how diet affects these antibodies is largely unknown. METHODS: We used world global data to demonstrate that colorectal cancer incidence and mortality are associated with increased national meat consumption. In a well-defined large cohort, we used glycomics to measure daily Neu5Gc intake from red meat and dairy, and investigated serum as well as affinity-purified anti-Neu5Gc antibodies. Based on 24-h dietary records, daily Neu5Gc intake was calculated for 19,621 subjects aged ≥ 18 years of the NutriNet-Santé study. Serum and affinity-purified anti-Neu5Gc antibodies were evaluated by ELISA and glycan microarrays in representative 120 individuals, each with at least eighteen 24-h dietary records (aged 45-60, Q1-Q4; aged > 60, Q1 and Q4; 10 men/women per quartile). RESULTS: We found that high-Neu5Gc diet, gender, and age affect the specificity, levels, and repertoires of anti-Neu5Gc IgG immune responses, but not their affinity. Men consumed more Neu5Gc than women, mostly from red meat (p = 0.0015), and exhibited higher overall serum anti-Neu5Gc IgG levels by ELISA (3.94 ng/µl versus 2.22 ng/µl, respectively; p = 0.039). Detailed glycan microarray analysis against 56 different glycans revealed high Neu5Gc-specificity with increased anti-Neu5Gc IgG and altered repertoires, associated with higher consumption of Neu5Gc from red meat and cow dairy. Affinity purification of serum anti-Neu5Gc antibodies revealed increased levels and biased array repertoire patterns, without an increase in antibody affinity, in individuals consuming higher Neu5Gc levels. Furthermore, in a high-meat diet, antibody diversity patterns on glycan microarrays shifted towards Neu5Gcα3-linked glycans, increasing the α3/α6-glycans ratio score. CONCLUSIONS: We found a clear link between the levels and repertoire of serum anti-Neu5Gc IgG and Neu5Gc intake from red meat and dairy. These precise rational methodologies allowed to develop a Gcemic index to simplify the assessment of Neu5Gc in foods that could potentially be adapted for dietary recommendations to reduce cancer risk.


Subject(s)
Antibodies/blood , Neoplasms/genetics , Neuraminic Acids/blood , Animals , Carbohydrates , Cohort Studies , Female , France , Humans , Male , Mice , Middle Aged , Prospective Studies
15.
Transpl Int ; 33(10): 1177-1184, 2020 10.
Article in English | MEDLINE | ID: mdl-32772429

ABSTRACT

Kidney paired donation (KPD) is a valuable way to overcome immunological incompatibility in the context of living donation, and several strategies have been implemented to boost its development. In this article, we reviewed the current state of the art in this field, with a particular focus on advanced KPD strategies, including the most recent idea of initiating living donor (LD) transplantation chains with a deceased donor (DD) kidney, first applied successfully in 2018. Since then, Italy has been running a national programme in which a chain-initiating kidney is selected from a DD pool and allocated to a recipient with an incompatible LD, and the LD's kidney is transplanted into a patient on the waiting list (WL). At this stage, since the ethical and logistic issues have been managed appropriately, KPD starting with a DD has proved to be a feasible strategy. It enables transplants in recipients of incompatible pairs without the need for desensitizing and also benefits patients on the WL who are allocated chain-ending kidneys from LDs (prioritizing sensitized patients and those on the WL for longer).


Subject(s)
Kidney Transplantation , Tissue and Organ Procurement , Humans , Italy , Kidney , Living Donors
16.
Am J Transplant ; 19(1): 123-131, 2019 01.
Article in English | MEDLINE | ID: mdl-29935060

ABSTRACT

The aim of this study was to determine how the Banff antibody-mediated rejection (ABMR) classification for kidney transplantation is interpreted in practice and affects therapy. The Banff Antibody-Mediated Injury Workgroup electronically surveyed clinicians and pathologists worldwide regarding diagnosis and treatment for 6 case-based scenarios. The participants' (95 clinicians and 72 renal pathologists) assigned diagnoses were compared to the Banff intended diagnoses (reference standard). The assigned diagnoses and reference standard differed by 26.1% (SD 28.1%) for pathologists and 34.5% (SD 23.3%) for clinicians. The greatest discordance between the reference standard and clinicians' diagnosis was when histologic features of ABMR were present but donor-specific antibody was undetected (49.4% [43/87]). For pathologists, the greatest discordance was in the case of acute/active ABMR C4d staining negative in a positive crossmatch transplant recipient (33.8% [23/68]). Treatment approaches were heterogeneous but linked to the assigned diagnosis. When acute/active ABMR was diagnosed by the clinician, treatment was recommended 95.3% (SD 18.4%) of the time vs only 77.7% (SD 39.2%) of the time when chronic active ABMR was diagnosed (P < .0001). In conclusion, the Banff ABMR classification is vulnerable to misinterpretation, which potentially has patient management implications. Continued efforts are needed to improve the understanding and standardized application of ABMR classification in the transplant community.


Subject(s)
Graft Rejection/diagnosis , Isoantibodies , Kidney Failure, Chronic/surgery , Kidney Transplantation , Pathology/standards , Allografts , Blood Grouping and Crossmatching , Complement C4b , Diagnostic Errors , Humans , International Cooperation , Kidney Failure, Chronic/diagnosis , Nephrology/standards , Observer Variation , Peptide Fragments/blood , Prognosis , Reference Standards , Reproducibility of Results , Surveys and Questionnaires , Terminology as Topic
17.
Immunity ; 32(6): 790-802, 2010 Jun 25.
Article in English | MEDLINE | ID: mdl-20605485

ABSTRACT

Tumor growth is associated with a profound alteration in myelopoiesis, leading to recruitment of immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs). We showed that among factors produced by various experimental tumors, the cytokines GM-CSF, G-CSF, and IL-6 allowed a rapid generation of MDSCs from precursors present in mouse and human bone marrow (BM). BM-MDSCs induced by GM-CSF+IL-6 possessed the highest tolerogenic activity, as revealed by the ability to impair the priming of CD8(+) T cells and allow long term acceptance of pancreatic islet allografts. Cytokines inducing MDSCs acted on a common molecular pathway and the immunoregulatory activity of both tumor-induced and BM-derived MDSCs was entirely dependent on the C/EBPbeta transcription factor. Adoptive transfer of tumor antigen-specific CD8(+) T lymphocytes resulted in therapy of established tumors only in mice lacking C/EBPbeta in the myeloid compartment, suggesting that C/EBPbeta is a critical regulator of the immunosuppressive environment created by growing cancers.


Subject(s)
Bone Marrow Cells/immunology , CCAAT-Enhancer-Binding Protein-beta/immunology , Immune Tolerance/immunology , Neoplasms/immunology , Tumor Escape/immunology , Adoptive Transfer , Animals , CCAAT-Enhancer-Binding Protein-beta/genetics , Cell Separation , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Granulocyte Colony-Stimulating Factor/biosynthesis , Granulocyte Colony-Stimulating Factor/immunology , Granulocyte-Macrophage Colony-Stimulating Factor/biosynthesis , Granulocyte-Macrophage Colony-Stimulating Factor/immunology , Humans , Immune Tolerance/genetics , Interleukin-6/biosynthesis , Interleukin-6/immunology , Mice , Neoplasms/genetics , Reverse Transcriptase Polymerase Chain Reaction , Tumor Escape/genetics
18.
Xenotransplantation ; 26(5): e12524, 2019 09.
Article in English | MEDLINE | ID: mdl-31115108

ABSTRACT

Two well-characterized carbohydrate epitopes are absent in humans but present in other mammals. These are galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc) which are introduced by the activities of two enzymes including α(1,3) galactosyltransferase (encoded by the GGTA1 gene) and CMP-Neu5Gc hydroxylase (encoded by the CMAH gene) that are inactive in humans but present in cattle. Hence, bovine-derived products are antigenic in humans who receive bioprosthetic heart valves (BHVs) or those that suffer from red meat syndrome. Using programmable nucleases, we disrupted (knockout, KO) GGTA1 and CMAH genes encoding for the enzymes that catalyse the synthesis of αGal and Neu5Gc, respectively, in both male and female bovine fibroblasts. The KO in clonally selected fibroblasts was detected by polymerase chain reaction (PCR) and confirmed by Sanger sequencing. Selected fibroblasts colonies were used for somatic cell nuclear transfer (SCNT) to produce cloned embryos that were implanted in surrogate recipient heifers. Fifty-three embryos were implanted in 33 recipients heifers; 3 pregnancies were carried to term and delivered 3 live calves. Primary cell cultures were established from the 3 calves and following molecular analyses confirmed the genetic deletions. FACS analysis showed the double-KO phenotype for both antigens confirming the mutated genotypes. Availability of such cattle double-KO model lacking both αGal and Neu5Gc offers a unique opportunity to study the functionality of BHV manufactured with tissues of potentially lower immunogenicity, as well as a possible new clinical approaches to help patients with red meat allergy syndrome due to the presence of these xenoantigens in the diet.


Subject(s)
Animals, Genetically Modified , Antigens, Heterophile/metabolism , Cytidine Monophosphate/analogs & derivatives , Galactose/metabolism , Galactosyltransferases/genetics , Gene Knockout Techniques , Mixed Function Oxygenases/genetics , Neuraminic Acids/metabolism , Animals , Antigens, Heterophile/immunology , Bioprosthesis , Cattle , Cytidine Monophosphate/immunology , Cytidine Monophosphate/metabolism , Female , Fibroblasts/immunology , Food Hypersensitivity/immunology , Galactose/immunology , Galactosyltransferases/deficiency , Heart Valve Prosthesis , Humans , Male , Mixed Function Oxygenases/deficiency , Neuraminic Acids/immunology , Transplantation, Heterologous
19.
Xenotransplantation ; 26(6): e12535, 2019 11.
Article in English | MEDLINE | ID: mdl-31293002

ABSTRACT

Humans cannot synthesize N-glycolylneuraminic acid (Neu5Gc) but dietary Neu5Gc can be absorbed and deposited on endothelial cells (ECs) and diet-induced anti-Neu5Gc antibodies (Abs) develop early in human life. While the interaction of Neu5Gc and diet-induced anti-Neu5Gc Abs occurs in all normal individuals, endothelium activation by elicited anti-Neu5Gc Abs following a challenge with animal-derived materials, such as following xenotransplantation, had been postulated. Ten primary human EC preparations were cultured with affinity-purified anti-Neu5Gc Abs from human sera obtained before or after exposure to Neu5Gc-glycosylated rabbit IgGs (elicited Abs). RNAs of each EC preparation stimulated in various conditions by purified Abs were exhaustively sequenced. EC transcriptomic patterns induced by elicited anti-Neu5Gc Abs, compared with pre-existing ones, were analyzed. qPCR, cytokines/chemokines release, and apoptosis were tested on some EC preparations. The data showed that anti-Neu5Gc Abs induced 967 differentially expressed (DE) genes. Most DE genes are shared following EC activation by pre-existing or anti-human T-cell globulin (ATG)-elicited anti-Neu5Gc Abs. Compared with pre-existing anti-Neu5Gc Abs, which are normal component of ECs environment, elicited anti-Neu5Gc Abs down-regulated 66 genes, including master genes of EC function. Furthermore, elicited anti-Neu5Gc Abs combined with complement-containing serum down-regulated most transcripts mobilized by serum alone. Both types of anti-Neu5Gc Abs-induced a dose- and complement-dependent release of selected cytokines and chemokines. Altogether, these data show that, compared with pre-existing anti-Neu5Gc Abs, ATG-elicited anti-Neu5Gc Abs specifically modulate genes related to cytokine responses, MAPkinase cascades, chemotaxis, and integrins and do not skew the EC transcriptome toward a pro-inflammatory profile in vitro.


Subject(s)
Antibodies/pharmacology , Endothelial Cells/drug effects , Endothelium/metabolism , Transcriptome/genetics , Animals , Antibodies/immunology , Endothelial Cells/immunology , Humans , Immunoglobulin G/metabolism , Transcriptome/immunology , Transplantation, Heterologous/methods
20.
Clin Transplant ; 33(10): e13666, 2019 10.
Article in English | MEDLINE | ID: mdl-31310687

ABSTRACT

Cytomegalovirus (CMV) remains a major cause of morbidity and mortality in allogeneic hematopoietic stem cell transplantation (allo-HSCT) and solid organ transplantation (SOT) recipients. In view of the uncertainties on the assessment and prevention of CMV infection in both transplant procedures, three Italian scientific societies for HSCT and SOT and for Clinical Microbiology appointed a panel of experts to compose a framework of recommendations. Recommendations were derived from a comprehensive analysis of the scientific literature and from a multidisciplinary consensus conference process. The lack of adequate clinical trials focused on certain diagnostic procedures, and antiviral intervention forced the panel to use the methods of consensus for shaping some recommendations. Recommendations concerning the two types of transplant were given for the following issues: assessment of pretransplant CMV serostatus, immunological monitoring after transplant, CMV prophylaxis with antivirals, CMV preemptive strategy, and CMV prophylaxis with immunoglobulin infusion and with adoptive immunotherapy. The questions raised by and the recommendations resulting from this consensus conference project may contribute to the improvement of certain crucial aspects of the management of CMV infections in allo-HSCT and in SOT populations.


Subject(s)
Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/prevention & control , Cytomegalovirus/isolation & purification , Hematopoietic Stem Cell Transplantation/adverse effects , Organ Transplantation/adverse effects , Cytomegalovirus Infections/etiology , Cytomegalovirus Infections/virology , Humans , Societies, Medical , Transplantation, Homologous
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