Savino Sciascia1, Rohan Willis2, Vittorio Pengo3, Steve Krilis4, Danieli Andrade5, Maria G Tektonidou6, Amaia Ugarte7, Cecilia Chighizola8, D Ware Branch9, Roger A Levy10, Cecilia Nalli11, Paul R Fortin12, Michelle Petri13, Esther Rodriguez14, Ignasi Rodriguez-Pinto15, Tatsuya Atsumi16, Iana Nascimento5, Renata Rosa5, Alessandra Banzato3, Doruk Erkan17, Hannah Cohen18, Maria Efthymiou19, Ian Mackie19, Maria Laura Bertolaccini20. 1. Center of Research of Immunopathology and Rare Diseases, University of Turin, Italy. Electronic address: savino.sciascia@unito.it. 2. Antiphospholipid Standardization Laboratory, Department of Internal Medicine, Rheumatology Division, University of Texas Medical Branch, Galveston, TX, USA. 3. Clinical Cardiology, Thrombosis Center, Department of Cardiac Thoracic and Vascular Sciences, University of Padua, Padua, Italy. 4. Department of Infectious Diseases, Immunology and Sexual Health, St George Hospital, Sydney, Australia. 5. Division of Rheumatology, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil. 6. University of Athens, Athens, Greece. 7. Hospital Universitario Cruces Bizkaia, Spain. 8. University of Milan, Milan, Italy. 9. University of Utah and Intermountain Healthcare, Salt Lake City, UT, USA. 10. State University of Rio de Janeiro, Rio de Janeiro, Brazil. 11. Department of Clinical and Experimental Science, University of Brescia, Brescia, Italy. 12. CHU de Quebec - Universite Laval, Quebec, Canada. 13. Johns Hopkins University, Baltimore, MD, USA. 14. Hospital Universitario 12 de Octubre, Madrid, Spain. 15. Department of Autoimmune Diseases, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain. 16. Hokkaido University Hospital, Sapporo, Japan. 17. Barbara Volcker Center for Women and Rheumatic Diseases, Hospital for Special Surgery, Weill Cornell Medicine, New York, NY, USA. 18. Haemostasis Research Unit, Department of Haematology, University College London, London, UK; Department of Haematology, University College London Hospitals NHS Foundation Trust, London, UK. 19. Haemostasis Research Unit, Department of Haematology, University College London, London, UK. 20. Academic Department of Vascular Surgery, Cardiovascular School of Medicine & Sciences, King's College London, UK.
Abstract
BACKGROUND: The APS ACTION International Clinical Database and Repository includes a secure web-based data capture system storing patient information including demographics, antiphospholipid antibodies (aPL)-related medical history, and aPL tests. Despite efforts at harmonization, inter-assay variability remains a problem in aPL testing. As a clinical repository open to researchers, ensuring comparability between assays and consistency in results between APS ACTION laboratories is essential to the validity of studies emerging from this network. OBJECTIVE: To assess the level of agreement between an aPL-registry inclusion and core laboratory (core lab) anticardiolipin antibody (aCL) and anti-β2-glycoprotein-I antibody (aβ2GPI) ELISA testing results. METHODS: Patients are recruited from 25 international centers based on positive aPL tests at inclusion. All samples are retested at the corresponding national APS ACTION core lab to confirm aPL positivity based on standard validated protocols. We analysed the categorical agreement, degree of linear association, and correlation between inclusion (local laboratory) and core lab aPL tests. Samples were included in this study only if results of aPL testing with ELISA at baseline were available. RESULTS: 497 registry samples underwent confirmatory aPL tests. Categorical agreement between the inclusion and core lab values, as expressed by Cohen's kappa coefficients, ranged between 0.61 and 0.80 (as substantial agreement). The correlation between quantitative results in the aCL and aβ2GPI was better for IgM and IgA compared to IgG (Spearman rho 0.789 and 0.666 vs. 0.600 for aCL and rho 0.892 and 0.744 vs. 0.432 for aβ2GPI). CONCLUSIONS: The results of inclusion for aCL and aβ2GPI tests used for recruitment into the registry were in agreement to the results obtained by the APS ACTION core laboratories; aCL and aβ2GPI results showed very good categorical agreement. This agreement increased when considering high titer (>40 units) samples. APS ACTION is a reliable and useful research resource for APS.
BACKGROUND: The APS ACTION International Clinical Database and Repository includes a secure web-based data capture system storing patient information including demographics, antiphospholipid antibodies (aPL)-related medical history, and aPL tests. Despite efforts at harmonization, inter-assay variability remains a problem in aPL testing. As a clinical repository open to researchers, ensuring comparability between assays and consistency in results between APS ACTION laboratories is essential to the validity of studies emerging from this network. OBJECTIVE: To assess the level of agreement between an aPL-registry inclusion and core laboratory (core lab) anticardiolipin antibody (aCL) and anti-β2-glycoprotein-I antibody (aβ2GPI) ELISA testing results. METHODS:Patients are recruited from 25 international centers based on positive aPL tests at inclusion. All samples are retested at the corresponding national APS ACTION core lab to confirm aPL positivity based on standard validated protocols. We analysed the categorical agreement, degree of linear association, and correlation between inclusion (local laboratory) and core lab aPL tests. Samples were included in this study only if results of aPL testing with ELISA at baseline were available. RESULTS: 497 registry samples underwent confirmatory aPL tests. Categorical agreement between the inclusion and core lab values, as expressed by Cohen's kappa coefficients, ranged between 0.61 and 0.80 (as substantial agreement). The correlation between quantitative results in the aCL and aβ2GPI was better for IgM and IgA compared to IgG (Spearman rho 0.789 and 0.666 vs. 0.600 for aCL and rho 0.892 and 0.744 vs. 0.432 for aβ2GPI). CONCLUSIONS: The results of inclusion for aCL and aβ2GPI tests used for recruitment into the registry were in agreement to the results obtained by the APS ACTION core laboratories; aCL and aβ2GPI results showed very good categorical agreement. This agreement increased when considering high titer (>40 units) samples. APS ACTION is a reliable and useful research resource for APS.
Authors: Jae Won Kim; Tae Woo Kim; Keon Hee Ryu; Sun Gyoo Park; Chang Young Jeong; Dong Ho Park Journal: J Int Med Res Date: 2020-01 Impact factor: 1.671
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Authors: Yu Zuo; Shanea K Estes; Ramadan A Ali; Alex A Gandhi; Srilakshmi Yalavarthi; Hui Shi; Gautam Sule; Kelsey Gockman; Jacqueline A Madison; Melanie Zuo; Vinita Yadav; Jintao Wang; Wrenn Woodard; Sean P Lezak; Njira L Lugogo; Stephanie A Smith; James H Morrissey; Yogendra Kanthi; Jason S Knight Journal: Sci Transl Med Date: 2020-11-02 Impact factor: 17.956