{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T01:04:53Z","timestamp":1789693493190,"version":"4.0.1"},"reference-count":50,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,2,8]],"date-time":"2022-02-08T00:00:00Z","timestamp":1644278400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Pathogenic TMPRSS6 variants impairing matriptase-2 function result in inappropriately high hepcidin levels relative to body iron status, leading to iron refractory iron deficiency anemia (IRIDA). As diagnosing IRIDA can be challenging due to its genotypical and phenotypical heterogeneity, we assessed the transferrin saturation (TSAT)\/hepcidin ratio to distinguish IRIDA from multi-causal iron deficiency anemia (IDA). We included 20 IRIDA patients from a registry for rare inherited iron disorders and then enrolled 39 controls with IDA due to other causes. Plasma hepcidin-25 levels were measured by standardized isotope dilution mass spectrometry. IDA controls had not received iron therapy in the last 3 months and C-reactive protein levels were &lt;10.0 mg\/L. IRIDA patients had significantly lower TSAT\/hepcidin ratios compared to IDA controls, median 0.6%\/nM (interquartile range, IQR, 0.4\u20131.1%\/nM) and 16.7%\/nM (IQR, 12.0\u201324.0%\/nM), respectively. The area under the curve for the TSAT\/hepcidin ratio was 1.000 with 100% sensitivity and specificity (95% confidence intervals 84\u2013100% and 91\u2013100%, respectively) at an optimal cut-off point of 5.6%\/nM. The TSAT\/hepcidin ratio shows excellent performance in discriminating IRIDA from TMPRSS6-unrelated IDA early in the diagnostic work-up of IDA provided that recent iron therapy and moderate-to-severe inflammation are absent. These observations warrant further exploration in a broader IDA population.<\/jats:p>","DOI":"10.3390\/ijms23031917","type":"journal-article","created":{"date-parts":[[2022,2,8]],"date-time":"2022-02-08T23:37:48Z","timestamp":1644363468000},"page":"1917","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Transferrin Saturation\/Hepcidin Ratio Discriminates TMPRSS6-Related Iron Refractory Iron Deficiency Anemia from Patients with Multi-Causal Iron Deficiency Anemia"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1361-7002","authenticated-orcid":false,"given":"Hilde","family":"van der Staaij","sequence":"first","affiliation":[{"name":"Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center (Radboudumc), 6525 GA Nijmegen, The Netherlands"},{"name":"M\u00e1xima Medical Center (MMC), Department of Pediatrics, 5504 DB Veldhoven, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Albertine E.","family":"Donker","sequence":"additional","affiliation":[{"name":"Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center (Radboudumc), 6525 GA Nijmegen, The Netherlands"},{"name":"M\u00e1xima Medical Center (MMC), Department of Pediatrics, 5504 DB Veldhoven, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dirk L.","family":"Bakkeren","sequence":"additional","affiliation":[{"name":"M\u00e1xima Medical Center (MMC), Department of Clinical Chemistry, 5504 DB Veldhoven, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jan M. J. I.","family":"Salemans","sequence":"additional","affiliation":[{"name":"M\u00e1xima Medical Center (MMC), Department of Gastroenterology, 5504 DB Veldhoven, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lisette A. A.","family":"Mignot-Evers","sequence":"additional","affiliation":[{"name":"M\u00e1xima Medical Center (MMC), Emergency Department, 5504 DB Veldhoven, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marlies Y.","family":"Bongers","sequence":"additional","affiliation":[{"name":"M\u00e1xima Medical Center (MMC), Department of Gynecology, 5504 DB Veldhoven, The Netherlands"},{"name":"Maastricht University Medical Center, Department of Gynecology, 6229 HX Maastricht, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeanne P.","family":"Dieleman","sequence":"additional","affiliation":[{"name":"M\u00e1xima Medical Center Academy, M\u00e1xima Medical Center (MMC), 5504 DB Veldhoven, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tessel E.","family":"Galesloot","sequence":"additional","affiliation":[{"name":"Department for Health Evidence, Radboud Institute for Health Sciences, 6500 HB Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Coby M.","family":"Laarakkers","sequence":"additional","affiliation":[{"name":"Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center (Radboudumc), 6525 GA Nijmegen, The Netherlands"},{"name":"Hepcidinanalysis, Translational Metabolic Laboratory, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siem M.","family":"Klaver","sequence":"additional","affiliation":[{"name":"Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center (Radboudumc), 6525 GA Nijmegen, The Netherlands"},{"name":"Hepcidinanalysis, Translational Metabolic Laboratory, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1040-9446","authenticated-orcid":false,"given":"Dorine W.","family":"Swinkels","sequence":"additional","affiliation":[{"name":"Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Center (Radboudumc), 6525 GA Nijmegen, The Netherlands"},{"name":"Hepcidinanalysis, Translational Metabolic Laboratory, Geert Grooteplein 10, 6525 GA Nijmegen, The Netherlands"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.cell.2010.06.028","article-title":"Two to Tango: Regulation of Mammalian Iron Metabolism","volume":"142","author":"Hentze","year":"2010","journal-title":"Cell"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"344","DOI":"10.1016\/j.cell.2016.12.034","article-title":"A Red Carpet for Iron Metabolism","volume":"168","author":"Muckenthaler","year":"2017","journal-title":"Cell"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"502","DOI":"10.1016\/j.cmet.2008.09.012","article-title":"The Serine Protease Matriptase-2 (TMPRSS6) Inhibits Hepcidin Activation by Cleaving Membrane Hemojuvelin","volume":"8","author":"Silvestri","year":"2008","journal-title":"Cell Metab."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/bs.vh.2019.01.004","article-title":"Hepcidin and the BMP-SMAD pathway: An unexpected liaison","volume":"110","author":"Silvestri","year":"2019","journal-title":"Vitam. 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