Safety and efficacy of eculizumab in the prevention of antibody-mediated rejection in living-donor kidney transplant recipients requiring desensitization therapy: A randomized trial.

We report results of a phase 2, randomized, multicenter, open-label, two-arm study evaluating the safety and efficacy of eculizumab in preventing acute antibody-mediated rejection (AMR) in sensitized recipients of living-donor kidney transplants requiring pretransplant desensitization (NCT01399593). In total, 102 patients underwent desensitization. Posttransplant, 51 patients received standard of care (SOC) and 51 received eculizumab.

Banff survey on antibody-mediated rejection clinical practices in kidney transplantation: Diagnostic misinterpretation has potential therapeutic implications.

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).

Pharmacodynamic Monitoring of Tacrolimus-Based Immunosuppression in CD14+ Monocytes After Kidney Transplantation.

Background: Monocytes significantly contribute to ischemia-reperfusion injury and allograft rejection after kidney transplantation. However, the knowledge about the effects of immunosuppressive drugs on monocyte activation is limited. Conventional pharmacokinetic methods for immunosuppressive drug monitoring are not cell type-specific.

CD16+ Monocytes and Skewed Macrophage Polarization toward M2 Type Hallmark Heart Transplant Acute Cellular Rejection.

Background: During acute heart transplant rejection, infiltration of lymphocytes and monocytes is followed by endothelial injury and eventually myocardial fibrosis. To date, no information is available on monocyte-macrophage-related cellular shifts and their polarization status during rejection. Here, we aimed to define and correlate monocyte-macrophage endomyocardial tissue profiles obtained at rejection and time points prior to rejection, with corresponding serial blood samples in 25 heart transplant recipients experiencing acute cellular rejection.

Targeting the Monocyte-Macrophage Lineage in Solid Organ Transplantation.

There is an unmet clinical need for immunotherapeutic strategies that specifically target the active immune cells participating in the process of rejection after solid organ transplantation. The monocyte-macrophage cell lineage is increasingly recognized as a major player in acute and chronic allograft immunopathology. The dominant presence of cells of this lineage in rejecting allograft tissue is associated with worse graft function and survival.

The Effect of Tacrolimus and Mycophenolic Acid on CD14+ Monocyte Activation and Function.

Monocytes and macrophages play key roles in many disease states, including cellular and humoral rejection after solid organ transplantation (SOT). To suppress alloimmunity after SOT, immunosuppressive drug therapy is necessary. However, little is known about the effects of the immunosuppressive drugs tacrolimus and mycophenolic acid (MPA) on monocyte activation and function.

Lipid droplets hypertrophy: a crucial determining factor in insulin regulation by adipocytes.

Lipid droplets (LDs) hypertrophy in adipocytes is the main cause of energy metabolic system dysfunction, obesity and its afflictions such as T2D. However, the role of adipocytes in linking energy metabolic disorders with insulin regulation is unknown in humans. Human adipocytes constitutively synthesize and secrete insulin, which is biologically functional.

Rotterdam: main port for organ transplantation research in the Netherlands.

This overview describes the full spectrum of current pre-clinical and clinical kidney-, liver-, heart- and lung transplantation research performed in Erasmus MC - University Medical Centre in Rotterdam, The Netherlands. An update is provided on the development of a large living donor kidney transplantation program and on optimization of kidney allocation, including the implementation of a domino kidney-donation program. Our current research efforts to optimize immunosuppressive regimens and find novel targets for immunosuppressive therapy, our recent studies on prevention of ischemia-reperfusion-induced graft injury, our newest findings on stimulation of tissue regeneration, our novel approaches to prevent rejection and viral infection, and our latest insights in the regulation of allograft rejection, are summarized.

Limited efficacy of immunosuppressive drugs on CD8+ T cell-mediated and natural killer cell-mediated lysis of human renal tubular epithelial cells.

Background: Although CD8+ T cell-mediated and natural killer (NK) cell-mediated cytotoxicity against renal tubular epithelial cells (TECs) plays a crucial role during rejection, the degree of inhibition of these lytic immune responses by immunosuppressive drugs is unknown. We investigated the CD8 T-cell and NK cell responses induced by TECs in vitro and questioned how these processes are affected by immunosuppressive drugs.

Methods: Donor-derived TECs were co-cultured with recipient peripheral blood monocyte cells.

Human monocytes produce interferon-gamma upon stimulation with LPS.

Representing a crucial T-helper 1 cytokine, IFN-γ acts as an important bridge between innate and adaptive immunity and is involved in many acute and chronic pathologic states, such as autoimmune diseases and solid organ transplant rejection. At present, debate still prevails about the ability of human monocytes to produce IFN-γ. We aimed to investigate whether human monocytes possess the capacity to produce IFN-γ at mRNA and protein level.

Substantial proliferation of human renal tubular epithelial cell-reactive CD4+CD28null memory T cells, which is resistant to tacrolimus and everolimus.

Background: In spite of maintenance treatment with immunosuppressive drugs, tubulitis still occurs and can lead to structural kidney graft damage. We hypothesize that human renal tubular epithelial cells (TECs) trigger selective proliferation of recipient T-cell subsets with variable sensitivity to immunosuppressive drugs.

Methods: Recipient peripheral blood mononuclear cells were cocultured with donor-derived TECs for 7 days.

A shift towards pro-inflammatory CD16+ monocyte subsets with preserved cytokine production potential after kidney transplantation.

Background: The presence of monocyte-macrophage lineage cells in rejecting kidney transplants is associated with worse graft outcome. At present, it is still unclear how the monocyte-macrophage related responses develop after transplantation. Here, we studied the dynamics, phenotypic and functional characteristics of circulating monocytes during the first 6 months after transplantation and aimed to establish the differences between kidney transplant recipients and healthy individuals.

Differential effects of activated human renal epithelial cells on T-cell migration.

Background: Renal tubular epithelial cells (TECs) are one of the main targets of inflammatory insults during interstitial nephritis and kidney transplant rejection. While Th1 cells are know to be essential in the pathogenesis of rejection, the role of Th17 is still under debate. We hypothesize that TECs modulate the outcome of rejection process by production of distinct chemokines and cytokines that determine the attraction of different T-cell subsets.

The role of macrophage lineage cells in kidney graft rejection and survival.

Large numbers of macrophage lineage cells are present in transplants undergoing ischemia-reperfusion injury and rejection, and their presence correlates with a high probability of rejection. However, the extent to which monocytes and macrophages contribute to kidney graft rejection is poorly understood. The heterogeneity of the monocyte/macrophage lineage cells could be one of the reasons why these cells have been neglected up to now.

FoxP3 T cells and the pathophysiologic effects of brain death and warm ischemia in donor kidneys.

Background And Objectives: Forkhead box P3 regulatory T cells control inflammatory responses, but it remains unclear whether they inhibit brain death-initiated inflammation and tissue injury in deceased kidney donors. DESIGN, SETTING, PARTICIPANTS, MEASUREMENT: To study the actions of regulatory T cells at various stages of the donation and transplantation procedure, forkhead box P3, regulatory and inflammatory cytokine expression, and tissue injury markers were determined in time 0 kidney biopsies from deceased and living donors. Additionally, the interaction between forkhead box P3+ T cells and kidney injury molecule-1 by activated primary tubular epithelial cells was studied.

Viral double-stranded RNA sensors induce antiviral, pro-inflammatory, and pro-apoptotic responses in human renal tubular epithelial cells.

Viral infection in the kidney is characterized by tubular injury induced directly by the virus and/or by cytotoxic lymphocytes. Previously, we found that human tubular epithelial cells express Toll-like receptor 3 (TLR3), melanoma differentiation-associated gene 5 (MDA5), and retinoic acid-inducible gene-I (RIG-I), all sensors of double-stranded RNA (dsRNA) and potent inducers of antiviral activity. Here, we demonstrate increased expression of these three dsRNA sensors in kidney transplant biopsies during cytomegalovirus or BK virus infection.

SerpinB9 expression in human renal tubular epithelial cells is induced by triggering of the viral dsRNA sensors TLR3, MDA5 and RIG-I.

Background: Serine protease inhibitor B9 (serpinB9) protects against granzyme B-mediated apoptosis and could help to reduce tubular damage under inflammatory conditions like interstitial nephritis. Previously, we found that tubular serpinB9 expression was increased during subclinical rejection. Here, we studied the regulation of serpinB9 expression in tubular epithelial cells (TECs) under inflammatory conditions.

Urinary granzyme A mRNA is a biomarker to diagnose subclinical and acute cellular rejection in kidney transplant recipients.

The distinction between T-cell-mediated rejection (TCMR) and other causes of kidney transplant dysfunction such as tubular necrosis requires biopsy. Subclinical rejection (SCR), an established risk factor for chronic allograft dysfunction, can only be diagnosed by protocol biopsy. A specific non-invasive biomarker to monitor immunological graft status would facilitate diagnosis and treatment of common transplantation-related complications.

Advancement of mesenchymal stem cell therapy in solid organ transplantation (MISOT).

There is evolving interest in the use of mesenchymal stem cells (MSC) in solid organ transplantation. Pre-clinical transplantation models show efficacy of MSC in prolonging graft survival and a number of clinical studies are planned or underway. At a recent meeting of the MISOT consortium (MSC In Solid Organ Transplantation) the advances of these studies were evaluated and mechanisms underlying the potential effects of MSC discussed.

Serine proteases of the human immune system in health and disease.

Serine proteases form a large family of protein-cleaving enzymes that play an essential role in processes like blood coagulation, apoptosis and inflammation. Immune cells express a wide variety of serine proteases such as granzymes in cytotoxic lymphocytes, neutrophil elastase, cathepsin G and proteinase 3 in neutrophils and chymase and tryptase in mast cells. Regulation of proteolysis induced by these serine proteases is essential to prevent self-induced damage.

Intragraft FOXP3 protein or mRNA during acute renal allograft rejection correlates with inflammation, fibrosis, and poor renal outcome.

Background: Forkhead box (FOXP3) is considered to be a specific marker for regulatory T cells. The aim of this study was to correlate intragraft FOXP3 at mRNA and cellular levels during renal allograft rejection to response to therapy and late clinical outcome.

Methods: Immunostainings and quantitative reverse-transcriptase polymerase chain reaction for FOXP3, CD3, and transforming growth factor (TGF)-beta were performed and results were related to histopathologic and clinical outcome.

B cells in cluster or in a scattered pattern do not correlate with clinical outcome of renal allograft rejection.

Background: The role of CD20+ B cells in renal allograft rejection has been reappreciated. Importantly, recent studies suggest a relation between CD20+ B cell aggregates and poorer clinical outcome. In the present study, we attempted to confirm these early reports in a tightly controlled patient population and to differentiate between scattered infiltrates and clusters of B cells.

Humoral immunity in renal transplantation: clinical significance and therapeutic approach.

Donor-specific antibodies (DSA) form a significant barrier in solid organ transplantation of highly pre-sensitized candidates. Although avoiding transplantation over a positive cross-match test can largely prevent the occurrence of hyperacute antibody-mediated rejection, transplantation of highly pre-sensitized candidates is often complicated by the occurrence of acute and chronic antibody-mediated graft rejection leading to diminished graft function and survival. The pre-existent HLA and/or non-HLA-specific antibodies are without any doubt important contributing factors underlying humoral-mediated graft injury.