Publications by authors named "Naesens M"

Highly sensitized (HS) patients in need of kidney transplantation (KTx) typically spend a longer time waiting for compatible kidneys, are unlikely to receive an organ offer, and are at increased risk of antibody-mediated rejection (AMR). Desensitization using imlifidase, which is more rapid and removes total body immunoglobulin G (IgG) to a greater extent than other methods, enables transplantation to occur between HLA-incompatible (HLAi) donor-recipient pairs and allows patients to have greater access to KTx. However, when the project was launched there was limited data and clinical experience with desensitization in general and with imlifidase specifically.

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Microvascular inflammation (MVI) in kidney transplant biopsies is mainly associated with antibody-mediated rejection (AMR), sparking debate within the Banff Classification of Renal Allograft Pathology regarding its exclusivity. This study reviewed the literature on MVI in T cell-mediated rejection (TCMR) and analyzed MVI in our transplant population. We searched English publications in MEDLINE, Embase, Web of Science, Cochrane, and Google Scholar until June 2024, focusing on glomerulitis (g), peritubular capillaritis (ptc), or MVI in kidney transplant biopsies classified as TCMR.

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Purpose Of Review: This review explores the variability in preimplantation kidney biopsy processing methods, emphasizing their impact on histological interpretation and allocation decisions driven by biopsy findings. With the increasing use of artificial intelligence (AI) in digital pathology, it is timely to evaluate whether these advancements can overcome current challenges and improve organ allocation amidst a growing organ shortage.

Recent Findings: Significant inconsistencies exist in biopsy methodologies, including core versus wedge sampling, frozen versus paraffin-embedded processing, and variability in pathologist expertise.

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Lung transplantation is a life-saving therapeutic option for many chronic end-stage pulmonary diseases, but long-term survival may be limited by rejection of the transplanted organ. Since HLA disparity between donor and recipient plays a major role in rejection, we performed a single center, retrospective observational cohort analysis in our lung transplant cohort (n = 128) in which we calculated HLA compatibility scores for B-cell epitopes (HLAMatchmaker, HLA-EMMA), T-cell epitopes (PIRCHE-II) and missing self-induced NK cell activation (KIR Ligand Calculator). Adjusted Cox proportional hazards model was used to investigate the association between mismatched scores and time to development of donor-specific antibodies (DSA) post-transplant, time to first biopsy-proven acute rejection episode, freedom from CLAD, graft survival and overall survival.

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Long-term survival after lung transplantation is limited due to chronic lung allograft dysfunction (CLAD), which encompasses two main phenotypes: bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). Donor-derived cell-free DNA (dd-cfDNA) is a biomarker for (sub)clinical allograft injury and could be a tool for monitoring of lung allograft health across the (pre)clinical spectrum of CLAD. In this proof-of-concept study, we therefore assessed post-transplant plasma dd-cfDNA levels in 20 CLAD patients (11 BOS and 9 RAS) at three consecutive time points free from concurrent infection or acute rejection, during stable condition, preclinical CLAD, and established CLAD ( = 3 × 20 samples).

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The XVI-th Banff Meeting for Allograft Pathology was held in Banff, Alberta, Canada, from 19th-23rd September 2022, as a joint meeting with the Canadian Society of Transplantation. To mark the 30 anniversary of the first Banff Classification, pre-meeting discussions were held on the past, present, and future of the Banff Classification. This report is a summary of the meeting highlights that were most important in terms of their effect on the Classification, including discussions around microvascular inflammation and biopsy-based transcript analysis for diagnosis.

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Article Synopsis
  • Kidney structural cells actively participate in the rejection process of kidney transplants, alongside infiltrated immune cells, as shown through single-cell RNA sequencing of biopsies.
  • Upregulation of immune-related genes was observed in endothelial and epithelial cells, indicating their involvement in the alloimmune response, with distinct differences based on the kidney compartment.
  • A significant downregulation of energy metabolism in proximal tubular cells during inflammation correlates with reduced kidney function, emphasizing the graft's crucial role in driving and maintaining rejection after transplantation.
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Article Synopsis
  • The study investigates how competing risks, like allograft failure and death with a functioning graft, affect the performance of prognostic models used for kidney transplant recipients.
  • The research involves 11,046 kidney transplant recipients across 10 countries, developing models using various regression techniques to predict long-term graft failure while carefully evaluating their accuracy and reliability.
  • Results indicate that both standard Cox models and competing risk models provide similar predictions for graft failure, with high concordance indices, confirming their usefulness in clinical settings.
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Background: Cytomegalovirus (CMV) infection poses a significant risk to immunosuppressed transplant recipients, manifesting through primary infection, reinfection, or reactivation.

Methods: We analyzed the emergence of drug resistance in CMV infection in 3 patients who were later found to have received an allograft from a shared, deceased donor. The seronegative transplant recipients developed symptomatic CMV infections after bowel/pancreas, kidney, or lung transplantation.

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Although kidney transplantation from living donors (LD) offers better long-term results than from deceased donors (DD), elderly recipients are less likely to receive LD transplants than younger ones. We analyzed renal transplant outcomes from LD versus DD in elderly recipients with a propensity-matched score. This retrospective, observational study included the first single kidney transplants in recipients aged ≥65 years from two European registry cohorts (2013-2020, n = 4,257).

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Graft failure and recipient death with functioning graft are important competing outcomes after kidney transplantation. Risk prediction models typically censor for the competing outcome thereby overestimating the cumulative incidence. The magnitude of this overestimation is not well described in real-world transplant data.

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The Banff 2022 consensus introduced probable antibody-mediated rejection (AMR), characterized by mild AMR histologic features and human leukocyte antigen (HLA) donor-specific antibody (DSA) positivity. In a single-center observational cohort study of 1891 kidney transplant recipients transplanted between 2004 and 2021, 566 kidney biopsies were performed in 178 individual HLA-DSA-positive transplants. Evaluated at time of the first HLA-DSA-positive biopsy of each transplant (N = 178), 84 of the 178 (47.

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Baseline kidney function following kidney transplantation is often used in research and clinical decision-making yet is not well defined. Here, a method to determine baseline function was proposed and validated on three single-center retrospective cohorts consisting of 922 patients from Belgium (main cohort) and two validation cohorts of 987 patients from the Netherlands and 519 patients from Germany. For each transplant, a segmented regression model was fitted on the estimated glomerular filtration rate (eGFR) evolution during the first-year post-transplantation.

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Solid phase detection and identification of HLA antibodies in kidney transplantation currently relies on single antigen bead (Luminex®) assays, which is more sensitive than the previously used enzyme-linked immunosorbent assays (ELISA). To evaluate the impact of more sensitive HLA testing on antibody-mediated rejection (AMR) occurrence and allograft survival, we analysed 1818 renal allograft recipients transplanted between March 2004 and May 2021. In 2008, solid phase testing switched from ELISA to Luminex.

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Article Synopsis
  • Donor-derived cell-free DNA (dd-cfDNA) is an innovative noninvasive biomarker being studied for its ability to detect kidney allograft injuries, such as rejection.
  • In a study involving 2,882 kidney transplant recipients, high levels of dd-cfDNA were strongly linked to various types of allograft rejection, and it significantly improved prediction models beyond what's typically used in patient monitoring.
  • The study, which included diverse cohorts, reinforced that measuring dd-cfDNA could enhance the detection of even subtle rejection in stable patients, providing valuable insights for better transplant management.
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Rationale & Objective: Kidneys are vital for vitamin D metabolism, and disruptions in both production and catabolism occur in chronic kidney disease. Although vitamin D activation occurs in numerous tissues, the kidneys are the most relevant source of circulating active vitamin D. This study investigates extrarenal vitamin D activation and the impact of kidney transplantation on vitamin D metabolism in patients who are anephric.

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The KDIGO guideline for acute rejection treatment recommends use of corticosteroids and suggests using lymphocyte-depleting agents as second line treatment. Aim of the study was to determine the current practices of detection and treatment of TCMR of kidney allografts amongst European kidney transplant centres. An invitation was sent through ESOT/EKITA newsletters and through social media to transplant professionals in Europe for taking part in the survey.

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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.

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Key Points: The estimated composition of immune cells in kidney transplants correlates poorly with the primary rejection categories defined by Banff criteria. Spatial cell distribution could be coupled with a detailed cellular composition to assess causal triggers for allorecognition. Intragraft CD8temra cells showed strong and consistent association with graft failure, regardless of the Banff rejection phenotypes.

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The 2022 Banff classification for kidney allograft pathology introduced the category "microvascular inflammation DSA-negative and C4d-negative" for cases without evidence of a humoral cause. Many questions remain about the etiology, prognosis, and treatment of this phenotype. Cristoferi et al.

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Background: The outcomes after kidney transplantation (KT), including access, wait time, and other issues around the globe, have been studied. However, issues do vary from one country to another.

Methods: We obtained data from several countries from North America, South America, Europe, Asia, and Australia, including the number of patients awaiting KT from 2015, transplant rate per million population (pmp), proportion of living donor and deceased donor (LD/DD) KT, and posttransplant survival.

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