{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,27]],"date-time":"2026-10-27T16:39:01Z","timestamp":1793119141260,"version":"4.5.0"},"reference-count":33,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T00:00:00Z","timestamp":1761696000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Centro Cl\u00ednico Acad\u00e9mico de Lisboa","award":["FF-CCAL.05.2025"],"award-info":[{"award-number":["FF-CCAL.05.2025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metabolites"],"abstract":"<jats:p>Background\/Objectives: Rapid, objective phenotyping of donor kidneys is needed to support peri-implant decisions. Label-free Fourier-transform infrared (FTIR) spectroscopy of static cold-storage Celsior\u00ae perfusion fluid can discriminate kidneys recovered from donation after circulatory death (DCD) versus donation after brain death (DBD). Methods: Preservation solution from isolated kidney allografts (n = 10; 5 DCD\/5 DBD) matched on demographics was analyzed in the Amide I and fingerprint regions. Several spectral preprocessing steps were applied, and feature extraction was based on the Fast Correlation-Based Filter. Support vector machines and Na\u00efve Bayes were evaluated. Unsupervised structure was assessed based on cosine distance, multidimensional scaling, and hierarchical clustering. Two-dimensional correlation spectroscopy (2D-COS) was used to examine band co-variation. Results: Donor cohorts were well balanced, except for higher terminal serum creatinine in DCD. Quality metrics were comparable, indicating no systematic technical bias. In Amide I, derivatives improved classification, but performance remained modest (e.g., second derivative with feature selection yielded an area under the curve (AUC) of 0.88 and an accuracy of 0.90 for support vector machines; Na\u00efve Bayes reached an AUC of 0.92 with an accuracy of 0.70). The fingerprint window was most informative. Na\u00efve Bayes with second derivative plus feature selection identified bands at ~1202, ~1203, ~1342, and ~1413 cm\u22121 and achieved an AUC of 1.00 and an accuracy of 1.00. Unsupervised analyses showed coherent grouping in the fingerprint region, and 2D correlation maps indicated coordinated multi-band changes. Conclusions: Performance in this 10-sample pilot should be interpreted cautiously, as perfect leave-one-out cross-validation (LOOCV) estimates are vulnerable to overfitting. The findings are preliminary and hypothesis-generating, and they require confirmation in larger, multicenter cohorts with a pre-registered analysis pipeline and external validation.<\/jats:p>","DOI":"10.3390\/metabo15110702","type":"journal-article","created":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T03:44:39Z","timestamp":1761795879000},"page":"702","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Rapid FTIR Spectral Fingerprinting of Kidney Allograft Perfusion Fluids Distinguishes DCD from DBD Donors: A Pilot Machine Learning Study"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8911-3380","authenticated-orcid":false,"given":"Luis","family":"Ramalhete","sequence":"first","affiliation":[{"name":"Blood and Transplantation Center of Lisbon, Instituto Portugu\u00eas do Sangue e da Transplanta-\u00e7\u00e3o, Alameda das Linhas de Torres, n\u25e6 117, 1769-001 Lisbon, Portugal"},{"name":"Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"iNOVA4Health\u2014Advancing Precision Medicine, N\u00facleo de Investiga\u00e7\u00e3o em Doen\u00e7as Renais, Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9369-6486","authenticated-orcid":false,"given":"R\u00faben","family":"Ara\u00fajo","sequence":"additional","affiliation":[{"name":"Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"ISEL\u2014Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Em\u00eddio Navarro 1, 1959-007 Lisbon, Portugal"},{"name":"Instituto Polit\u00e9cnico de Lisboa, Estrada de Benfica Road 529, 1549-020 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0528-2716","authenticated-orcid":false,"given":"Miguel Bigotte","family":"Vieira","sequence":"additional","affiliation":[{"name":"Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"iNOVA4Health\u2014Advancing Precision Medicine, N\u00facleo de Investiga\u00e7\u00e3o em Doen\u00e7as Renais, Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"Nephrology, Hospital Curry Cabral, Unidade Local de Sa\u00fade de S\u00e3o Jos\u00e9, R. da Benefic\u00eancia 8, 1050-099 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4525-9062","authenticated-orcid":false,"given":"Emanuel","family":"Vigia","sequence":"additional","affiliation":[{"name":"Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"iNOVA4Health\u2014Advancing Precision Medicine, N\u00facleo de Investiga\u00e7\u00e3o em Doen\u00e7as Renais, Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"Hepatobiliopancreatic and Transplantation Center, Curry Cabral Hospital, Unidade Local de Sa\u00fade de S\u00e3o Jos\u00e9, R. da Benefic\u00eancia 8, 1050-099 Lisbon, Portugal"},{"name":"Centro Cl\u00ednico Acad\u00e9mico de Lisboa, 1169-024 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Pena","sequence":"additional","affiliation":[{"name":"Hepatobiliopancreatic and Transplantation Center, Curry Cabral Hospital, Unidade Local de Sa\u00fade de S\u00e3o Jos\u00e9, R. da Benefic\u00eancia 8, 1050-099 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sofia","family":"Carrelha","sequence":"additional","affiliation":[{"name":"Hepatobiliopancreatic and Transplantation Center, Curry Cabral Hospital, Unidade Local de Sa\u00fade de S\u00e3o Jos\u00e9, R. da Benefic\u00eancia 8, 1050-099 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3300-6033","authenticated-orcid":false,"given":"Anibal","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"iNOVA4Health\u2014Advancing Precision Medicine, N\u00facleo de Investiga\u00e7\u00e3o em Doen\u00e7as Renais, Nova Medical School, Faculdade de Ci\u00eancias M\u00e9dicas, NMS, FCM, Universidade Nova de Lisboa, 1169-056 Lisbon, Portugal"},{"name":"Nephrology, Hospital Curry Cabral, Unidade Local de Sa\u00fade de S\u00e3o Jos\u00e9, R. da Benefic\u00eancia 8, 1050-099 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5264-9755","authenticated-orcid":false,"given":"Cec\u00edlia R. C.","family":"Calado","sequence":"additional","affiliation":[{"name":"ISEL\u2014Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Em\u00eddio Navarro 1, 1959-007 Lisbon, Portugal"},{"name":"Instituto Polit\u00e9cnico de Lisboa, Estrada de Benfica Road 529, 1549-020 Lisbon, Portugal"},{"name":"Institute for Bioengineering and Biosciences (iBB), The Associate Laboratory Institute for Health and Bioeconomy-i4HB, Av. Rovisco Pais, 1049-001 Lisbon, Portugal"},{"name":"Instituto Superior T\u00e9cnico (IST), Av. Rovisco Pais, 1049-001 Lisbon, Portugal"},{"name":"Universidade de Lisboa (UL), Cidade Universit\u00e1ria, Alameda da Universidade, 1649-004 Lisbon, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"11","DOI":"10.21037\/acs-2024-dcd-0132","article-title":"Donation after Circulatory Death Transplantation: A Systematic Review and Meta-Analysis of Outcomes and Methods of Donation","volume":"14","author":"Jolliffe","year":"2025","journal-title":"Ann. Cardiothorac. Surg."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e1804","DOI":"10.1097\/TXD.0000000000001804","article-title":"Eligible DBD Donors Proceeding via the DCD Pathway: Incidence, Cause, and Outcomes in the United Kingdom","volume":"11","author":"Burgess","year":"2025","journal-title":"Transplant. 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Transplant."}],"container-title":["Metabolites"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-1989\/15\/11\/702\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T05:43:06Z","timestamp":1761802986000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-1989\/15\/11\/702"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,29]]},"references-count":33,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["metabo15110702"],"URL":"https:\/\/doi.org\/10.3390\/metabo15110702","relation":{},"ISSN":["2218-1989"],"issn-type":[{"value":"2218-1989","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,29]]}}}