20.500.12556/DiRROS-24057 Establishment of ELISA-comparable moderate and high thresholds for anticardiolipin and anti-β2 glycoprotein I chemiluminescent immunoassays according to the 2023 ACR/EULAR APS classification criteria and evaluation of their diagnostic performance Objectives: Recently published 2023 ACR/EULAR APS classification criteria emphasize the importance of quantifying single-, double-, and triple-antiphospholipid antibody positivity, distinguishing between IgG and IgM isotypes, and delineating moderate/high levels of anticardiolipin (aCL) and anti-β2 glycoprotein I (anti-β2GPI) antibodies. We aimed to establish clinically important moderate/high thresholds for aCL and anti-β2GPI IgG/IgM chemiluminescent immunoassays (CLIA), in particular QUANTA Flash, comparable to our in-house ELISAs used for over two decades, and to evaluate their diagnostic performance. Methods: QUANTA Flash CLIA and in-house ELISAs were used to measure aCL and anti-β2GPI IgG/IgM. Moderate thresholds for QUANTA Flash CLIA were determined using a non-parametric approach, calculating a 99th percentile on serum samples from 139 blood donors, and by mirroring the diagnostic performance of in-house ELISA on 159 patient samples. Results: Thresholds for QUANTA Flash CLIA achieving diagnostic performance equivalent to in-house ELISAs were 40 CU for moderate and 80 CU for high levels for aCL and anti-β2GPI IgG and IgM. The assays showed good qualitative agreement, ranging from 76.10 to 91.19 %. When considering in-house ELISA results, 14 out of 80 (17.5 %) patients did not fulfill the new ACR/EULAR laboratory classification criteria, while 27 out of 80 (33.8 %) did not when considering QUANTA Flash CLIA results. Conclusions: We determined moderate and high thresholds for aCL and anti-β2GPI IgG and IgM detected with QUANTA Flash CLIA, aligning with long-established in-house ELISA thresholds. These thresholds are crucial for seamlessly integrating of the new 2023 ACR/EULAR classification criteria into future observational clinical studies and trials. anti-β2GPI anticardiolipin antiphospholipid syndrome classification criteria anti-β2GPI antikardiolipin antifosfolipidni sindrom merila za razvrščanje Pošljite povratne informacije Stranska podokna Zgodovina Shranjeno true false true Angleški jezik Slovenski jezik Neznano 2025-11-10 13:20:28 2025-11-10 13:20:28 2025-11-13 04:02:51 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne: 5. 1. 2025; str. 164-176 iss. 1 Vol. 63 2025 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 0000-00-00 616-097 1437-4331 10.1515/cclm-2024-0570 203693059 RAZ_Zigon_Polona_2025.pdf RAZ_Zigon_Polona_2025.pdf 1 3C941B318F1C3CEFC25E85E7DEFD8897 9d5843b7e9e3e5a9eb5ad88cdb8c4c16d198ab889e9013598fe0b7261340bc1b 22dff057-be30-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=35757 https://www.degruyter.com/document/doi/10.1515/cclm-2024-0570/html 1 a8385561-be2f-11f0-94a7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=35756 Univerzitetni klinični center Ljubljana 0 0 0