170923 20260430151735.0 doi 10.11613/BM.2026.020701 sideral 148988 ART-2026-148988 eng Martinez-Marzo, Eva Urinary placental growth factor stability as a critical factor in the reliability of preeclampsia diagnosis 2026 Introduction: Placental growth factor (PlGF) is a key biomarker for diagnosing and predicting preeclampsia (PE). While serum-based PlGF assays are well established, urine has emerged as a promising non-invasive alternative matrix. However, the absence of urinary PlGF stability data remains a major preanalytical limitation. This study aimed to assess urinary PlGF stability under common preanalytical conditions, including refrigerated storage and a double freeze-thaw cycle. Materials and methods: A prospective study was conducted using urine samples from ten pregnant women. Each sample was processed under standard laboratory conditions and aliquoted into five tubes. One aliquot was immediately frozen at - 80 °C (T0), three were stored at 2-8 °C for 48, 96, and 168 hours before freezing, and one underwent a double freeze-thaw cycle. Urinary PlGF concentrations were measured using the Elecsys PlGF immunoassay on Roche Cobas e801 analyzer. Percent degradation (PD%) was calculated relative to baseline. A linear regression model was applied to estimate the time to exceed a maximum permissible instability (MPI) of ± 10 %. Results: Urinary PlGF remained stable at 2-8 °C for up to 48 hours, with a mean PD% of - 6 % (95% confidence interval (CI): - 9.1 to - 2.8). The regression model (PD% = - 0.0834 x Time (h)) estimated the - 10 % threshold at approximately 120 hours. After a double freeze-thaw cycle, the mean PD% was - 1.5 % (95% CI: - 3.4 to 0.4%). Conclusions: Urinary PlGF shows acceptable stability for up to 48 hours under refrigeration and is stable over two freeze-thaw cycles. These findings provide essential preanalytical data supporting its potential use in clinical and research settings. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/DGA/B46-20R info:eu-repo/grantAgreement/ES/DGA/B46-23R info:eu-repo/grantAgreement/ES/ISCIII-FEDER/CM22-00045 nfo:eu-repo/grantAgreement/ES/ISCIII/FI21-00224 info:eu-repo/grantAgreement/ES/ISCIII/PI22-143 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Peran, Maria (orcid)0000-0001-5459-1254 Lerma-Irureta, Juan Medel-Martinez, Ana Paules, Cristina Universidad de Zaragoza (orcid)0000-0001-6795-0367 Oros, Daniel Universidad de Zaragoza (orcid)0000-0002-8476-9161 Fabre, Marta Universidad de Zaragoza 1013 645 Universidad de Zaragoza Dpto. Cirugía Área Obstetricia y Ginecología 1011 615 Universidad de Zaragoza Dpto. Microb.Ped.Radio.Sal.Pú. Área Medic.Prevent.Salud Públ. 36, 2 (2026), [9 pp.] Biochemia Medica Biochemia medica 1330-0962 970688 http://zaguan.unizar.es/record/170923/files/texto_completo.pdf Versión publicada 2280407 http://zaguan.unizar.es/record/170923/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:170923 articulos driver 2026-04-30-13:57:10 ARTICLE