1. The use of machine learning in the diagnosis of kidney allograft rejection : current knowledge and applicationsTanja Belčič Mikič, Miha Arnol, 2024, review article Abstract: Abstract: Kidney allograft rejection is one of the main limitations to long-term kidney transplant survival. The diagnostic gold standard for detecting rejection is a kidney biopsy, an invasive procedure that can often give imprecise results due to complex diagnostic criteria and high interobserver variability. In recent years, several additional diagnostic approaches to rejection have been investigated, some of them with the aid of machine learning (ML). In this review, we addressed studies that investigated the detection of kidney allograft rejection over the last decade using various ML algorithms. Various ML techniques were used in three main categories: (a) histopathologic assessment of kidney tissue with the aim to improve the diagnostic accuracy of a kidney biopsy, (b) assessment of gene expression in rejected kidney tissue or peripheral blood and the development of diagnostic classifiers based on these data, (c) radiologic assessment of kidney tissue using diffusion-weighted magnetic resonance imaging and the construction of a computer-aided diagnostic system. In histopathology, ML algorithms could serve as a support to the pathologist to avoid misclassifications and overcome interobserver variability. Diagnostic platforms based on biopsy-based transcripts serve as a supplement to a kidney biopsy, especially in cases where histopathologic diagnosis is inconclusive. ML models based on radiologic evaluation or gene signature in peripheral blood may be useful in cases where kidney biopsy is contraindicated in addition to other non-invasive biomarkers. The implementation of ML-based diagnostic methods is usually slow and undertaken with caution considering ethical and legal issues. In summary, the approach to the diagnosis of rejection should be individualized and based on all available diagnostic tools (including ML-based), leaving the responsibility for over- and under-treatment in the hands of the clinician.
Keywords: kidney transplantation, rejection, diagnosis, machine learning, kidney biopsy
Published in DiRROS: 08.12.2025; Views: 449; Downloads: 116
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2. Complications on the feeding artery after an arterio-venous fistula closure in patients after kidney transplantation : a national cohort studyMatej Zrimšek, Barbara Vajdič Trampuž, Matija Jelenc, Juš Kšela, Jakob Gubenšek, 2025, original scientific article Abstract: Background: Arteriovenous fistulas (AVFs) in kidney transplant recipients are sometimes closed, either as a policy or due to complications. We collected data on the incidence of complications after AVF closure in a national cohort of transplanted patients. Methods: Patients who received a kidney transplant between 2000 and 2015 and had a functional AVF that was later ligated or extirpated were included. Medical records were searched for arterial complications on the arm with the closed AVF. Furthermore, all patients who were still alive in January 2023 were invited for a follow-up arterial ultrasound exam. Results: Sixty patients were included; mean follow-up was 9.3 ± 3.8 years. There were five (8% cumulative incidence) patients with symptomatic arterial thrombosis and three (5% incidence) with a symptomatic feeding artery aneurysm. Prospective ultrasound exams were performed in 50 patients; the mean diameter of the brachial artery was almost doubled on the arm with the closed AVF (8.1 ± 3.2 versus 4.7 ± 0.7 mm; P < .001). Additional asymptomatic complications were found in nine patients (18% incidence): seven cases (14% incidence) of arterial thrombosis, some extending up to the axillary artery, and three (6% incidence) brachial artery aneurysms. All patients in whom the thrombosis spread to the brachial artery had large brachial arteries (>10 mm) or an aneurysm. Conclusion: We observed a high cumulative incidence of arterial thrombosis (20%) and brachial artery aneurysms (10%), sometimes developing several years after AVF closure. These complications should be taken into account when contemplating closure of a well-developed AVF and an AVF-preserving approach with flow reduction surgery might be preferred in some cases.
Keywords: kidney transplantation, arterial thrombosis, arteriovenous fistula, complications, true brachial artery aneurysm, ultrasound exam
Published in DiRROS: 01.12.2025; Views: 774; Downloads: 118
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3. Prophylactic treatment of hepatitis C virus infection after kidney transplantation with the combination of glecaprevir/pibrentasvir and sofosbuvir in a highly sensitized hepatitis c virus-negative recipient : a case report and review of the literatureTanja Belčič Mikič, Igor Sterle, Mojca Matičič, Miha Arnol, 2025, other scientific articles Abstract: Background: Since the discovery of successful direct-acting antiviral (DAA) treatment, kidneys from hepatitis C virus (HCV) RNA-positive donors represent a new opportunity to expand the organ donor pool for HCV-negative recipients. Case presentation: In this paper, we describe a unique case of transplantation of an HCV genotype 3a-infected kidney into an HCV-negative recipient who was highly sensitized, with a virtual panel-reactive antibody level of 99.96%. Prior to the kidney transplantation, the recipient received DAA treatment with glecaprevir/pibrentasvir as a viable prophylactic strategy. Post-transplant, the recipient received a triple-combination DAA regimen with glecaprevir/pibrentasvir/sofosbuvir, which continued for 12 weeks. Subsequently, viral load was undetectable at 12 and 24 weeks after treatment, with no significant adverse events associated with DAA therapy. A 12-month post-transplantation biopsy revealed mixed rejection requiring treatment. The 19-month follow-up showed a favorable outcome regarding the function of the kidney allograft and the recipient’s quality of life. HCV-positive transplantation allowed our recipient to receive a kidney from an immunologically compatible donor without donor-specific antibodies and the need for desensitization strategies. Conclusions: Each transplant center should decide on the selection of candidates for kidney transplantation from HCV RNA-positive donors to HCV-negative recipients, the availability and choice of DAA treatment, and post-transplant follow-up. Our case emphasizes the need for early DAA treatment based on viral load and HCV genotyping, as well as for careful post-transplant surveillance including protocol biopsies.
Keywords: kidney transplantation, HCV RNA, direct-acting antiviral (DAA), glecaprevir/pibrentasvir, sensitization, case report
Published in DiRROS: 12.11.2025; Views: 243; Downloads: 127
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4. Feasibility of droplet digital PCR analysis of plasma cell-free DNA from kidney transplant patientsBarbara Jerič Kokelj, Maja Štalekar, Sebastian Vencken, David Dobnik, Polona Kogovšek, Matjaž Stanonik, Miha Arnol, Maja Ravnikar, 2021, original scientific article Abstract: Increasing research demonstrates the potential of donor-derived cell-free DNA (dd-cfDNA) as a biomarker for monitoring the health of various solid organ transplants. Several methods have been proposed for cfDNA analysis, including real-time PCR, digital PCR, and next generation sequencing-based approaches. We sought to revise the droplet digital PCR (ddPCR)-based approach to quantify relative dd-cfDNA in plasma from kidney transplant (KTx) patients using a novel pilot set of assays targeting single nucleotide polymorphisms that have a very high potential to distinguish cfDNA from two individuals. The assays are capable of accurate quantification of down to 0.1% minor allele content when analyzing 165 ng of human DNA. We found no significant differences in the yield of extracted cfDNA using the three different commercial kits tested. More cfDNA was extracted from the plasma of KTx patients than from healthy volunteers, especially early after transplantation. The median level of donor-derived minor alleles in KTx samples was 0.35%. We found that ddPCR using the evaluated assays within specific range is suitable for analysis of KTx patientsʼ plasma but recommend prior genotyping of donor DNA and performing reliable preamplification of cfDNA.
Keywords: kidney transplantation, droplet digital PCR, plasma cell-free DNA, minor allele quantification, assay evaluation, graft health monitoring
Published in DiRROS: 19.07.2024; Views: 1535; Downloads: 632
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