{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,4]],"date-time":"2026-04-04T05:01:40Z","timestamp":1775278900010,"version":"3.50.1"},"reference-count":51,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T00:00:00Z","timestamp":1774915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medicina"],"abstract":"<jats:p>Background and Objectives: Renal transplantation is the optimal treatment for end-stage renal disease, yet long-term allograft survival remains threatened by immune-mediated injury and chronic nephropathy. Conventional monitoring using serum creatinine and protocol biopsy suffers from limited sensitivity for early, subclinical injury. Liquid biopsy-based biomarkers offer a non-invasive alternative. Materials and Methods: We conducted a systematic narrative review of studies published between January 2010 and December 2024, identified through PubMed, Scopus, and Web of Science. Results: Extracellular vesicles carry injury-specific molecular cargo reflecting the biological state of tubular, glomerular, and endothelial cells; urinary EV CXCL9 protein and exosomal CD3\u03b5 mRNA have demonstrated AUC values of 0.81\u20130.88 for the detection of T-cell-mediated rejection. Donor-derived cell-free DNA quantifies global graft cell death; the FDA-cleared AlloSure assay achieves an AUC of 0.74 and NPV of 84% at the validated \u22651.0% threshold established in the DART trial. Donor-specific antibodies\u2014particularly complement-fixing C1q-positive DSAs\u2014confer markedly inferior 5-year graft survival compared with DSA-negative recipients (54% versus 93%). Multi-biomarker panels integrating all three modalities yield AUCs of 0.88\u20130.94 and NPVs of 91\u201395%. Conclusions: The integration of EV, ddcfDNA, and DSA monitoring into a unified surveillance framework offers a clinically meaningful advance over creatinine-based monitoring. Prospective randomized trials confirming improvement in long-term allograft survival will be the critical next step.<\/jats:p>","DOI":"10.3390\/medicina62040664","type":"journal-article","created":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T15:14:43Z","timestamp":1775142883000},"page":"664","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Combined Biomarker Approach Using Extracellular Vesicles, Donor-Derived Cell-Free DNA, and Donor-Specific Antibodies for Monitoring Renal Allograft Function: A Narrative Review"],"prefix":"10.3390","volume":"62","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0906-1745","authenticated-orcid":false,"given":"Kumar","family":"Digvijay","sequence":"first","affiliation":[{"name":"Department of Renal Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3715-7266","authenticated-orcid":false,"given":"Henrik","family":"Birn","sequence":"additional","affiliation":[{"name":"Department of Renal Medicine, Aarhus University Hospital, 8200 Aarhus N, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1111\/ajt.16982","article-title":"OPTN\/SRTR 2020 Annual Data Report: Kidney","volume":"22","author":"Lentine","year":"2022","journal-title":"Am. J. Transplant."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"388","DOI":"10.1111\/j.1600-6143.2011.03840.x","article-title":"Understanding the Causes of Kidney Transplant Failure: The Dominant Role of Antibody-Mediated Rejection and Nonadherence","volume":"12","author":"Mengel","year":"2012","journal-title":"Am. J. Transplant."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2318","DOI":"10.1111\/ajt.15898","article-title":"The Banff 2019 Kidney Meeting Report (I): Updates on and clarification of criteria for T cell\u2013 and antibody-mediated rejection","volume":"20","author":"Loupy","year":"2020","journal-title":"Am. J. Transplant."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1483","DOI":"10.1097\/TP.0000000000002961","article-title":"for the DeKAF Investigators*. Late Graft Loss After Kidney Transplantation: Is \u201cDeath With Function\u201d Really Death With a Functioning Allograft?","volume":"104","author":"Gaston","year":"2019","journal-title":"Transplantation"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1330","DOI":"10.25122\/jml-2022-0181","article-title":"Relevant biomarkers of kidney allograft rejection","volume":"15","author":"Loga","year":"2023","journal-title":"J. Med. Life"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Lazarou, C., Moysidou, E., Christodoulou, M., Stai, S., Lioulios, G., Kasimatis, E., Fylaktou, A., and Stangou, M. (2025). Protocol Biopsies in Kidney Transplant Recipients: Current Practice After Much Discussion. Biomedicines, 13.","DOI":"10.3390\/biomedicines13071660"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1186\/s12967-023-03960-8","article-title":"Liquid biopsies: The future of cancer early detection","volume":"21","author":"Connal","year":"2023","journal-title":"J. Transl. Med."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Ciferri, M.C., Quarto, R., and Tasso, R. (2021). Extracellular Vesicles as Biomarkers and Therapeutic Tools: From Pre-Clinical to Clinical Applications. Biology, 10.","DOI":"10.3390\/biology10050359"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"15061","DOI":"10.1038\/s41598-022-19017-7","article-title":"Combining donor-derived cell-free DNA and donor specific antibody testing as non-invasive biomarkers for rejection in kidney transplantation","volume":"12","author":"Butiu","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1186\/s12951-023-01973-5","article-title":"Extracellular vesicles: A rising star for therapeutics and drug delivery","volume":"21","author":"Du","year":"2023","journal-title":"J. Nanobiotechnol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Venturella, M., Criscuoli, M., Carraro, F., Naldini, A., and Zocco, D. (2021). Interplay between Hypoxia and Extracellular Vesicles in Cancer and Inflammation. Biology, 10.","DOI":"10.3390\/biology10070606"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1038\/nrneph.2017.98","article-title":"Extracellular vesicles in renal disease","volume":"13","author":"Karpman","year":"2017","journal-title":"Nat. Rev. Nephrol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e12404","DOI":"10.1002\/jev2.12404","article-title":"Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches","volume":"13","author":"Welsh","year":"2024","journal-title":"J. Extracell. Vesicles"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1056\/NEJMoa1215555","article-title":"Urinary-Cell mRNA Profile and Acute Cellular Rejection in Kidney Allografts","volume":"369","author":"Suthanthiran","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"57","DOI":"10.3389\/fmed.2014.00057","article-title":"Perturbations in the Urinary Exosome in Transplant Rejection","volume":"1","author":"Sigdel","year":"2015","journal-title":"Front. Med."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2634","DOI":"10.1111\/ajt.12426","article-title":"Multicenter Validation of Urinary CXCL9 as a Risk-Stratifying Biomarker for Kidney Transplant Injury","volume":"13","author":"Hricik","year":"2013","journal-title":"Am. J. Transplant."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1016\/j.molimm.2019.12.011","article-title":"Complement fragments are biomarkers of antibody-mediated endothelial injury","volume":"118","author":"Stites","year":"2020","journal-title":"Mol. Immunol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"855","DOI":"10.1681\/ASN.2013121289","article-title":"Platelets in Early Antibody-Mediated Rejection of Renal Transplants","volume":"26","author":"Kuo","year":"2015","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Bo\u0161tjan\u010di\u010d, E., Ve\u010deri\u0107-Haler, \u017d., and Kojc, N. (2021). The Role of Immune-Related miRNAs in the Pathology of Kidney Transplantation. Biomolecules, 11.","DOI":"10.3390\/biom11081198"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Oshikawa-Hori, S., Yokota-Ikeda, N., Sonoda, H., and Ikeda, M. (2019). Urinary extracellular vesicular release of aquaporins in patients with renal transplantation. BMC Nephrol., 20.","DOI":"10.1186\/s12882-019-1398-7"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"20360","DOI":"10.3402\/jev.v2i0.20360","article-title":"Standardization of sample collection, isolation and analysis methods in extracellular vesicle research","volume":"2","author":"Witwer","year":"2013","journal-title":"J. Extracell. Vesicles"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Oellerich, M., Budde, K., Osmanodja, B., Bornemann-Kolatzki, K., Beck, J., Sch\u00fctz, E., and Walson, P.D. (2022). Donor-derived cell-free DNA as a diagnostic tool in transplantation. Front. Genet., 13.","DOI":"10.3389\/fgene.2022.1031894"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"6229","DOI":"10.1073\/pnas.1013924108","article-title":"Universal noninvasive detection of solid organ transplant rejection","volume":"108","author":"Snyder","year":"2011","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"890","DOI":"10.1016\/j.jmoldx.2016.07.003","article-title":"Validation of a Clinical-Grade Assay to Measure Donor-Derived Cell-Free DNA in Solid Organ Transplant Recipients","volume":"18","author":"Grskovic","year":"2016","journal-title":"J. Mol. Diagn."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"2657","DOI":"10.1097\/TP.0000000000002665","article-title":"Analytical Validation of a Single-nucleotide Polymorphism-based Donor-derived Cell-free DNA Assay for Detecting Rejection in Kidney Transplant Patients","volume":"103","author":"Liang","year":"2019","journal-title":"Transplantation"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"2221","DOI":"10.1681\/ASN.2016091034","article-title":"Cell-Free DNA and Active Rejection in Kidney Allografts","volume":"28","author":"Bloom","year":"2017","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"3087","DOI":"10.1111\/ajt.15416","article-title":"Absolute quantification of donor-derived cell-free DNA as a marker of rejection and graft injury in kidney transplantation: Results from a prospective observational study","volume":"19","author":"Oellerich","year":"2019","journal-title":"Am. J. Transplant."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2529","DOI":"10.1016\/j.ajt.2025.07.2484","article-title":"Donor-derived cell-free DNA significantly improves rejection yield in kidney transplant biopsies","volume":"25","author":"Bromberg","year":"2025","journal-title":"Am. J. Transplant."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1016\/j.kint.2021.11.034","article-title":"Clinical outcomes from the Assessing Donor-derived cell-free DNA Monitoring Insights of kidney Allografts with Longitudinal surveillance (ADMIRAL) study","volume":"101","author":"Bu","year":"2022","journal-title":"Kidney Int."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"e14258","DOI":"10.1111\/petr.14258","article-title":"Use of a donor-derived cell-free DNA assay to monitor treatment response in pediatric renal transplant recipients with allograft rejection","volume":"26","author":"Steggerda","year":"2022","journal-title":"Pediatr. Transplant."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"E5503","DOI":"10.1073\/pnas.1508736112","article-title":"Plasma DNA tissue mapping by genome-wide methylation sequencing for noninvasive prenatal, cancer, and transplantation assessments","volume":"112","author":"Sun","year":"2015","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1150","DOI":"10.1056\/NEJMra1802677","article-title":"Antibody-Mediated Rejection of Solid-Organ Allografts","volume":"379","author":"Loupy","year":"2018","journal-title":"N. Engl. J. Med."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1157","DOI":"10.1111\/j.1600-6143.2012.04013.x","article-title":"Evolution and Clinical Pathologic Correlations of De Novo Donor-Specific HLA Antibody Post Kidney Transplant","volume":"12","author":"Wiebe","year":"2012","journal-title":"Am. J. Transplant."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1159\/000510747","article-title":"Molecular Mechanisms of Antibody-Mediated Rejection and Accommodation in Organ Transplantation","volume":"144","author":"Kenta","year":"2020","journal-title":"Nephron"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1097\/TP.0b013e31827a19cc","article-title":"Consensus Guidelines on the Testing and Clinical Management Issues Associated With HLA and Non-HLA Antibodies in Transplantation","volume":"95","author":"Tait","year":"2013","journal-title":"Transplantation"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1681\/ASN.2014111120","article-title":"IgG Donor-Specific Anti-Human HLA Antibody Subclasses and Kidney Allograft Antibody-Mediated Injury","volume":"27","author":"Lefaucheur","year":"2016","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1215","DOI":"10.1056\/NEJMoa1302506","article-title":"Complement-Binding Anti-HLA Antibodies and Kidney-Allograft Survival","volume":"369","author":"Loupy","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2106","DOI":"10.1111\/ajt.13700","article-title":"Acquisition of C3d-Binding Activity by De Novo Donor-Specific HLA Antibodies Correlates With Graft Loss in Nonsensitized Pediatric Kidney Recipients","volume":"16","author":"Comoli","year":"2016","journal-title":"Am. J. Transplant."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Crespo, M., Llin\u00e0s-Mallol, L., Redondo-Pach\u00f3n, D., Butler, C., Gimeno, J., P\u00e9rez-S\u00e1ez, M.J., Burballa, C., Buxeda, A., Arias-Cabrales, C., and Folgueiras, M. (2021). Non-HLA Antibodies and Epitope Mismatches in Kidney Transplant Recipients With Histological Antibody-Mediated Rejection. Front. Immunol., 12.","DOI":"10.3389\/fimmu.2021.703457"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.ajt.2022.11.013","article-title":"Clinical recommendations for posttransplant assessment of anti\u2013HLA (Human Leukocyte Antigen) donor-specific antibodies: A Sensitization in Transplantation: Assessment of Risk consensus document","volume":"23","author":"Lefaucheur","year":"2023","journal-title":"Am. J. Transplant."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"606","DOI":"10.1681\/ASN.2017070749","article-title":"Dynamic Prognostic Score to Predict Kidney Allograft Survival in Patients with Antibody-Mediated Rejection","volume":"29","author":"Viglietti","year":"2017","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1038\/s41581-021-00428-0","article-title":"Liquid biopsies: Donor-derived cell-free DNA for the detection of kidney allograft injury","volume":"17","author":"Oellerich","year":"2021","journal-title":"Nat. Rev. Nephrol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2435","DOI":"10.1097\/TP.0000000000004212","article-title":"Combining Donor-derived Cell-free DNA Fraction and Quantity to Detect Kidney Transplant Rejection Using Molecular Diagnoses and Histology as Confirmation","volume":"106","author":"Halloran","year":"2022","journal-title":"Transplantation"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1689","DOI":"10.1111\/tri.13970","article-title":"Diagnostic value of donor-derived cell-free DNA to predict antibody-mediated rejection in donor-specific antibody-positive renal allograft recipients","volume":"34","author":"Mayer","year":"2021","journal-title":"Transpl. Int."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1448","DOI":"10.1016\/j.ekir.2020.06.018","article-title":"Urinary Protein Biomarker Panel for the Diagnosis of Antibody-Mediated Rejection in Kidney Transplant Recipients","volume":"5","author":"Mertens","year":"2020","journal-title":"Kidney Int. Rep."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"e13850","DOI":"10.1111\/petr.13850","article-title":"Donor-derived cell-free DNA (dd-cfDNA) for detection of allograft rejection in pediatric kidney transplants","volume":"25","author":"Puliyanda","year":"2021","journal-title":"Pediatr. Transplant."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1097\/TP.0000000000004624","article-title":"The Molecular Phenotype of Kidney Transplants: Insights From the MMDx Project","volume":"108","author":"Halloran","year":"2024","journal-title":"Transplantation"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1721","DOI":"10.1681\/ASN.2014040399","article-title":"Subclinical Rejection Phenotypes at 1 Year Post-Transplant and Outcome of Kidney Allografts","volume":"26","author":"Loupy","year":"2015","journal-title":"J. Am. Soc. Nephrol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1056\/NEJMoa2400763","article-title":"A Randomized Phase 2 Trial of Felzartamab in Antibody-Mediated Rejection","volume":"391","author":"Mayer","year":"2024","journal-title":"N. Engl. J. Med."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1097\/TP.0000000000004267","article-title":"An Assessment of the Value of Donor-derived Cell-free DNA Surveillance in Patients With Preserved Kidney Allograft Function","volume":"107","author":"Huang","year":"2022","journal-title":"Transplantation"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1384","DOI":"10.1093\/ndt\/gfae282","article-title":"Donor-derived cell-free DNA monitoring for early diagnosis of antibody-mediated rejection after kidney transplantation: A randomized trial","volume":"40","author":"Akifova","year":"2024","journal-title":"Nephrol. Dial. Transplant."}],"container-title":["Medicina"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/4\/664\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,4]],"date-time":"2026-04-04T04:17:34Z","timestamp":1775276254000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1648-9144\/62\/4\/664"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,31]]},"references-count":51,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["medicina62040664"],"URL":"https:\/\/doi.org\/10.3390\/medicina62040664","relation":{},"ISSN":["1648-9144"],"issn-type":[{"value":"1648-9144","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,31]]}}}