{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,21]],"date-time":"2026-02-21T06:19:56Z","timestamp":1771654796696,"version":"3.50.1"},"reference-count":18,"publisher":"BMJ","issue":"11","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2024,6,1]]},"published-print":{"date-parts":[[2024,11]]},"abstract":"<jats:p>Acquired factor V (FV) inhibitors are extremely rare and present with a broad spectrum ranging from asymptomatic laboratory anomalies to life-threatening critical bleeds. The overall rarity along with the heterogeneity of clinical presentations poses a challenge in diagnosis. There is currently no standard of care immunosuppressive therapy (IST) in these settings. Most patients in the literature receive multiple agents, including but not limited to combinations of IST and\/or recombinant products.<\/jats:p>\n               <jats:p>Here, we present a case of a man in his 50s who initially presented with oozing at peripheral IV and tracheostomy sites with intermittent epistaxis. He was later found to have an FV activity level of less than 1% and an FV inhibitor titre of 184 Bethesda units\/mL. The patient was initially stabilised with fresh frozen plasma, platelets and tranexamic acid and treated with intravenous immunoglobulin and glucocorticoids. However, this resulted in only mild improvement in his coagulation studies. He was then treated with weekly doses of rituximab for 4\u2009weeks with ongoing glucocorticoids without complications. This adds to the growing literature on rituximab as a possible treatment option for acquired FV inhibitors.<\/jats:p>","DOI":"10.1136\/bcr-2023-256475","type":"journal-article","created":{"date-parts":[[2024,11,18]],"date-time":"2024-11-18T12:30:42Z","timestamp":1731933042000},"page":"e256475","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Acquired factor V inhibitor treated with rituximab"],"prefix":"10.1136","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-1039-7169","authenticated-orcid":false,"given":"Faisal","family":"Ansari","sequence":"first","affiliation":[{"name":"Western Michigan University Homer Stryker MD School of Medicine, Kalamazoo, Michigan, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yurhee","family":"Lee","sequence":"additional","affiliation":[{"name":"UCLA Medical Center Olive View, Sylmar, California, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Umar","family":"Ansari","sequence":"additional","affiliation":[{"name":"Western University of Health Sciences, Pomona, California, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Phyllis","family":"Kim","sequence":"additional","affiliation":[{"name":"UCLA Medical Center Olive View, Sylmar, California, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2024,11,18]]},"reference":[{"key":"2025082801133492000_17.11.e256475.1","first-page":"791","article-title":"[Acquired factor V inhibitor]","volume":"61","author":"Yamada","year":"2020","journal-title":"Rinsho Ketsueki"},{"key":"2025082801133492000_17.11.e256475.2","doi-asserted-by":"crossref","DOI":"10.1002\/rth2.12700","article-title":"Coagulation factor inhibitors in COVID\u201019: from SARS\u2010CoV\u20102 vaccination to infection","volume":"6","author":"Jacobs","year":"2022","journal-title":"Res Pract Thromb Haemost"},{"key":"2025082801133492000_17.11.e256475.3","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1097\/MBC.0000000000001009","article-title":"Acquired factor V inhibitor in the setting of Coronavirus disease 2019 infection","volume":"32","author":"Bennett","year":"2021","journal-title":"Blood Coagul Fibrinolysis"},{"key":"2025082801133492000_17.11.e256475.4","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1055\/s-0041-1735452","article-title":"Acquired factor V inhibitor after Coronavirus disease 2019","volume":"48","author":"Chiurazzi","year":"2022","journal-title":"Semin Thromb Hemost"},{"key":"2025082801133492000_17.11.e256475.5","doi-asserted-by":"crossref","first-page":"4188","DOI":"10.1182\/blood.V91.11.4188","article-title":"Inhibitory anti-factor V antibodies bind to the factor V C2 domain and are associated with hemorrhagic manifestations","volume":"91","author":"Ortel","year":"1998","journal-title":"Blood"},{"key":"2025082801133492000_17.11.e256475.6","doi-asserted-by":"publisher","DOI":"10.1002\/ajh.2830420410"},{"key":"2025082801133492000_17.11.e256475.7","doi-asserted-by":"publisher","DOI":"10.1038\/46594"},{"key":"2025082801133492000_17.11.e256475.8","doi-asserted-by":"crossref","first-page":"1728","DOI":"10.5858\/arpa.2016-0445-RS","article-title":"Factor V inhibitors: a diagnostic and therapeutic challenge","volume":"141","author":"Olson","year":"2017","journal-title":"Arch Pathol Lab Med"},{"key":"2025082801133492000_17.11.e256475.9","doi-asserted-by":"publisher","DOI":"10.1182\/asheducation-2006.1.432"},{"key":"2025082801133492000_17.11.e256475.10","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1055\/s-0033-1336832","article-title":"Mixing tests: diagnostic aides in the investigation of prolonged prothrombin times and activated partial thromboplastin times","volume":"39","author":"Kershaw","year":"2013","journal-title":"Semin Thromb Hemost"},{"key":"2025082801133492000_17.11.e256475.11","doi-asserted-by":"publisher","DOI":"10.1007\/s11239-010-0529-6"},{"key":"2025082801133492000_17.11.e256475.12","doi-asserted-by":"crossref","first-page":"852","DOI":"10.1160\/TH08-11-0767","article-title":"Acquired factor V inhibitor. A problem-based systematic review","volume":"101","author":"Ang","year":"2009","journal-title":"Thromb Haemost"},{"key":"2025082801133492000_17.11.e256475.13","doi-asserted-by":"publisher","DOI":"10.1002\/ajh.21056"},{"key":"2025082801133492000_17.11.e256475.14","doi-asserted-by":"publisher","DOI":"10.1002\/ajh.20181"},{"key":"2025082801133492000_17.11.e256475.15","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1016\/S0950-3536(98)80050-4","article-title":"2 acquired factor V inhibitors","volume":"11","author":"Kn\u00f6bl","year":"1998","journal-title":"Baillieres Clin Haematol"},{"key":"2025082801133492000_17.11.e256475.16","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1182\/blood.V60.1.59.59","article-title":"Radioimmunoassay of factor V in human plasma and platelets","volume":"60","author":"Tracy","year":"1982","journal-title":"Blood"},{"key":"2025082801133492000_17.11.e256475.17","unstructured":"Stoj KM , Pierro J . Factor V deficiency [Internet]. Treasure Island, FL: StatPearls Publishing, 2022."},{"key":"2025082801133492000_17.11.e256475.18","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1007\/s12185-015-1742-z","article-title":"Complete response of acquired FV inhibitor to rituximab","volume":"101","author":"Ma","year":"2015","journal-title":"Int J Hematol"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2023-256475","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,28]],"date-time":"2025-08-28T08:13:43Z","timestamp":1756368823000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2023-256475"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11]]},"references-count":18,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2024,11,18]]},"published-print":{"date-parts":[[2024,11]]}},"alternative-id":["10.1136\/bcr-2023-256475"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2023-256475","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11]]}}}