{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,16]],"date-time":"2025-12-16T12:51:06Z","timestamp":1765889466815,"version":"3.44.0"},"reference-count":20,"publisher":"Georg Thieme Verlag KG","issue":"06","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Semin Thromb Hemost"],"published-print":{"date-parts":[[2025,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>Factor VIII (FVIII) inhibitors represent antibodies that develop against coagulation FVIII and reduce FVIII functional activity. FVIII inhibitors may develop in patients with congenital hemophilia A (CHA) in response to infused FVIII (allo-antibodies) or in patients without CHA in a variety of situations (auto-antibodies; acquired hemophilia A). We report updated findings for FVIII inhibitor testing in our geographic region using recent data (testing for the past 5 years; 2020\u20132024 inclusive) from the RCPAQAP (Royal College of Pathologists of Australasia Quality Assurance Program), an international external quality assessment (EQA) program, with over 80 enrolments for the FVIII inhibitor module. Four samples are assessed each year, with these comprising both FVIII inhibitor negative samples and FVIII inhibitor positive samples with various inhibitor titers. This EQA data largely evidences favorable findings in FVIII inhibitor testing in our jurisdiction, with &gt;99% of test results interpreted correctly by participants for the presence (\u201cdetected\u201d) or absence (\u201cnot detected\u201d) of FVIII inhibitors in assessed samples. Moreover, most errors in interpretation appear to be transcription or data entry errors rather than analytic errors. The coefficient of variation (CV) values for FVIII inhibitor samples were moderately high, ranging from 25 to 40%, irrespective of the inhibitor titer (range: 3\u201364 Bethesda units [BU]\/mL) or the method (i.e., Bethesda vs. Nijmegen). In conclusion, most laboratories were able to correctly identify the presence versus absence of FVIII inhibitors, although laboratory-reported titers varied moderately.<\/jats:p>","DOI":"10.1055\/a-2546-0441","type":"journal-article","created":{"date-parts":[[2025,2,27]],"date-time":"2025-02-27T19:15:56Z","timestamp":1740683756000},"page":"698-705","source":"Crossref","is-referenced-by-count":2,"title":["Factor Inhibitor Testing: An Update from Australasia\/Asia-Pacific"],"prefix":"10.1055","volume":"51","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2103-1661","authenticated-orcid":false,"given":"Emmanuel J.","family":"Favaloro","sequence":"additional","affiliation":[{"name":"Department of Haematology, Sydney Centres for Thrombosis and Haemostasis, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital, Westmead, NSW, Australia"},{"name":"Faculty of Science and Health, Charles Sturt University, Wagga Wagga, NSW, Australia"},{"name":"School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Westmead Hospital, Westmead, NSW, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sandya","family":"Arunachalam","sequence":"additional","affiliation":[{"name":"RCPAQAP Haematology, St Leonards, NSW, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"194","published-online":{"date-parts":[[2025,4,7]]},"reference":[{"issue":"01","key":"ref1","doi-asserted-by":"crossref","first-page":"13","DOI":"10.3390\/jcm14010013","article-title":"Laboratory assessment of factor VIII inhibitors: when is it required? 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A follow up to a large multicentre evaluation","volume":"39","author":"E J Favaloro","year":"2007","journal-title":"Pathology"},{"issue":"08","key":"ref10","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1055\/s-0029-1245112","article-title":"Investigations from external quality assurance programs reveal a high degree of variation in the laboratory identification of coagulation factor inhibitors","volume":"35","author":"E J Favaloro","year":"2009","journal-title":"Semin Thromb Hemost"},{"issue":"04","key":"ref11","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1111\/j.1365-2516.2009.02173.x","article-title":"Laboratory identification of factor VIII inhibitors in the real world: the experience from Australasia","volume":"16","author":"E J Favaloro","year":"2010","journal-title":"Haemophilia"},{"issue":"03","key":"ref12","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1055\/s-0033-1334464","article-title":"External quality assessment of factor VIII inhibitor assays","volume":"39","author":"R A Bonar","year":"2013","journal-title":"Semin Thromb Hemost"},{"issue":"08","key":"ref13","doi-asserted-by":"crossref","first-page":"786","DOI":"10.1055\/s-0029-1245111","article-title":"The between-laboratory variation of factor VIII inhibitor testing: the experience of the external quality assessment program of the ECAT foundation","volume":"35","author":"P Meijer","year":"2009","journal-title":"Semin Thromb Hemost"},{"issue":"03","key":"ref14","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1111\/hae.14158","article-title":"Factor VIII\/IX inhibitor testing practices in the United Kingdom: results of a UKHCDO and UKNEQAS national survey","volume":"27","author":"P Batty","year":"2021","journal-title":"Haemophilia"},{"issue":"S 05","key":"ref15","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1111\/hae.12991","article-title":"Quality laboratory issues in bleeding disorders","volume":"22","author":"D M Adcock","year":"2016","journal-title":"Haemophilia"},{"issue":"06","key":"ref16","doi-asserted-by":"crossref","first-page":"735","DOI":"10.1016\/j.thromres.2013.09.018","article-title":"Validation of 4% albumin as a diluent in the Bethesda Assay for FVIII inhibitors","volume":"132","author":"G W Kershaw","year":"2013","journal-title":"Thromb Res"},{"issue":"10","key":"ref17","doi-asserted-by":"crossref","first-page":"2003","DOI":"10.1111\/j.1538-7836.2011.04479.x","article-title":"The factor VIII inhibitor assays can be standardized: results of a workshop","volume":"9","author":"B Verbruggen","year":"2011","journal-title":"J Thromb Haemost"},{"issue":"06","key":"ref18","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1055\/s-0032-1321490","article-title":"Acquired functional coagulation inhibitors: review on epidemiology, results of a wet-workshop on laboratory detection, and implications for quality of inhibitor diagnosis","volume":"38","author":"M Dardikh","year":"2012","journal-title":"Semin Thromb Hemost"},{"issue":"04","key":"ref19","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1309\/AJCPMKP94CODILWS","article-title":"Laboratory assessment of factor VIII inhibitor titer: the North American Specialized Coagulation Laboratory Association experience","volume":"131","author":"E I Peerschke","year":"2009","journal-title":"Am J Clin Pathol"},{"key":"ref20","doi-asserted-by":"publisher","DOI":"10.1111\/ijlh.14447","article-title":"Activated protein C resistance testing: an update from Australasia\/Asia-Pacific","author":"E J Favaloro","year":"2025","journal-title":"Int J Lab Hematol"}],"container-title":["Seminars in Thrombosis and Hemostasis"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/www.thieme-connect.de\/products\/ejournals\/pdf\/10.1055\/a-2546-0441.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,14]],"date-time":"2025-08-14T23:43:09Z","timestamp":1755214989000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.thieme-connect.de\/DOI\/DOI?10.1055\/a-2546-0441"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,27]]},"references-count":20,"journal-issue":{"issue":"06","published-online":{"date-parts":[[2025,8,8]]},"published-print":{"date-parts":[[2025,9]]}},"URL":"https:\/\/doi.org\/10.1055\/a-2546-0441","archive":["Portico","CLOCKSS"],"relation":{},"ISSN":["0094-6176","1098-9064"],"issn-type":[{"type":"print","value":"0094-6176"},{"type":"electronic","value":"1098-9064"}],"subject":[],"published-other":{"date-parts":[[2025,2,27]]},"published":{"date-parts":[[2025,2,27]]}}}