{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T14:37:48Z","timestamp":1790779068626,"version":"4.1.0"},"reference-count":22,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,6,13]],"date-time":"2024-06-13T00:00:00Z","timestamp":1718236800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"French Ministry of Public Health","award":["PHRC-19-0402"],"award-info":[{"award-number":["PHRC-19-0402"]}]},{"name":"French Ministry of Public Health","award":["NCT04868578"],"award-info":[{"award-number":["NCT04868578"]}]},{"name":"French Ministry of Public Health","award":["49RC08-0018"],"award-info":[{"award-number":["49RC08-0018"]}]},{"name":"French Ministry of Public Health","award":["NCT01446380"],"award-info":[{"award-number":["NCT01446380"]}]},{"name":"French Ministry of Public Health","award":["ANR KI-PYRINA AAP CE17"],"award-info":[{"award-number":["ANR KI-PYRINA AAP CE17"]}]},{"name":"Angers University Hospital","award":["PHRC-19-0402"],"award-info":[{"award-number":["PHRC-19-0402"]}]},{"name":"Angers University Hospital","award":["NCT04868578"],"award-info":[{"award-number":["NCT04868578"]}]},{"name":"Angers University Hospital","award":["49RC08-0018"],"award-info":[{"award-number":["49RC08-0018"]}]},{"name":"Angers University Hospital","award":["NCT01446380"],"award-info":[{"award-number":["NCT01446380"]}]},{"name":"Angers University Hospital","award":["ANR KI-PYRINA AAP CE17"],"award-info":[{"award-number":["ANR KI-PYRINA AAP CE17"]}]},{"name":"Agence Nationale de la Recherche","award":["PHRC-19-0402"],"award-info":[{"award-number":["PHRC-19-0402"]}]},{"name":"Agence Nationale de la Recherche","award":["NCT04868578"],"award-info":[{"award-number":["NCT04868578"]}]},{"name":"Agence Nationale de la Recherche","award":["49RC08-0018"],"award-info":[{"award-number":["49RC08-0018"]}]},{"name":"Agence Nationale de la Recherche","award":["NCT01446380"],"award-info":[{"award-number":["NCT01446380"]}]},{"name":"Agence Nationale de la Recherche","award":["ANR KI-PYRINA AAP CE17"],"award-info":[{"award-number":["ANR KI-PYRINA AAP CE17"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Pseudoxanthoma elasticum (PXE) is a rare inherited systemic disease responsible for a juvenile peripheral arterial calcification disease. The clinical diagnosis of PXE is only based on a complex multi-organ phenotypic score and\/or genetical analysis. Reduced plasma inorganic pyrophosphate concentration [PPi]p has been linked to PXE. In this study, we used a novel and accurate method to measure [PPi]p in one of the largest cohorts of PXE patients, and we reported the valuable contribution of a cutoff value to PXE diagnosis. Plasma samples and clinical records from two French reference centers for PXE (PXE Consultation Center, Angers, and FAVA-MULTI South Competent Center, Nice) were assessed. Plasma PPi were measured in 153 PXE and 46 non-PXE patients. The PPi concentrations in the plasma samples were determined by a new method combining enzymatic and ion chromatography approaches. The best match between the sensitivity and specificity (Youden index) for diagnosing PXE was determined by ROC analysis. [PPi]p were lower in PXE patients (0.92 \u00b1 0.30 \u00b5mol\/L) than in non-PXE patients (1.61 \u00b1 0.33 \u00b5mol\/L, p &lt; 0.0001), corresponding to a mean reduction of 43 \u00b1 19% (SD). The PPi cutoff value for diagnosing PXE in all patients was 1.2 \u00b5mol\/L, with a sensitivity of 83.3% and a specificity of 91.1% (AUC = 0.93), without sex differences. In patients aged &lt;50 years (i.e., the age period for PXE diagnosis), the cutoff PPi was 1.2 \u00b5mol\/L (sensitivity, specificity, and AUC of 93%, 96%, and 0.97, respectively). The [PPi]p shows high accuracy for diagnosing PXE; thus, quantifying plasma PPi represents the first blood assay for diagnosing PXE.<\/jats:p>","DOI":"10.3390\/ijms25126502","type":"journal-article","created":{"date-parts":[[2024,6,14]],"date-time":"2024-06-14T03:52:53Z","timestamp":1718337173000},"page":"6502","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["A Plasma Pyrophosphate Cutoff Value for Diagnosing Pseudoxanthoma Elasticum"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4267-6207","authenticated-orcid":false,"given":"Isabelle","family":"Rubera","sequence":"first","affiliation":[{"name":"University C\u00f4te d\u2019Azur, CNRS, LP2M, Labex ICST, 06107 Nice, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laetitia","family":"Clotaire","sequence":"additional","affiliation":[{"name":"University C\u00f4te d\u2019Azur, CNRS, LP2M, Labex ICST, 06107 Nice, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5978-8117","authenticated-orcid":false,"given":"Audrey","family":"Laurain","sequence":"additional","affiliation":[{"name":"University C\u00f4te d\u2019Azur, CNRS, LP2M, Labex ICST, 06107 Nice, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6147-9201","authenticated-orcid":false,"given":"Alexandre","family":"Destere","sequence":"additional","affiliation":[{"name":"Pharmacology Department, Nice University Hospital, 06000 Nice, France"},{"name":"FAVA-MULTI South Competence Center for Rare Arterial Calcifying Disease, Nice University Hospital, 06000 Nice, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ludovic","family":"Martin","sequence":"additional","affiliation":[{"name":"PXE Reference Center, MAGEC Nord, Angers University Hospital, 49000 Angers, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1127-2346","authenticated-orcid":false,"given":"Christophe","family":"Duranton","sequence":"additional","affiliation":[{"name":"University C\u00f4te d\u2019Azur, CNRS, LP2M, Labex ICST, 06107 Nice, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Georges","family":"Leftheriotis","sequence":"additional","affiliation":[{"name":"University C\u00f4te d\u2019Azur, CNRS, LP2M, Labex ICST, 06107 Nice, France"},{"name":"FAVA-MULTI South Competence Center for Rare Arterial Calcifying Disease, Nice University Hospital, 06000 Nice, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1038\/76102","article-title":"Mutations in a Gene Encoding an ABC Transporter Cause Pseudoxanthoma Elasticum","volume":"25","author":"Urban","year":"2000","journal-title":"Nat. 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