A high titer of acquired factor V inhibitor in a hemodialysis patient who developed arterial thrombosis
An 87-year-old man with diabetes mellitus was admitted to control recurrent bleeding from hemodialysis puncture sites. He was a smoker and had been diagnosed with arteriosclerosis obliterans. His PT and APTT were markedly prolonged, and all coagulation factors were markedly decreased (factor V [FV] activity < 1%) or below the measurement threshold, with the exception of fibrinogen and factor XIII. Neither PT nor APTT were corrected upon mixing with normal plasma. A high titer of FV inhibitor was found at 415 BU/mL, and anti-FV autoantibody was detected by both immunoblot assay and ELISA. Prednisolone administration and plasma exchange partially improved prolonged PT and APTT and decreased the FV inhibitor level. Five months later, he manifested symptoms of severe ischemia in both legs. Angiography revealed diffuse stenosis downstream of both common iliac arteries. Endovascular therapy was repeated four times, the prednisolone dose was reduced, and low-dose antiplatelet therapy was initiated. After the final successful endovascular therapy, arterial thrombosis was detected using ultrasound and angiography. Aspiration thrombectomy and thrombolytic therapy failed to achieve recanalization, and necrosis of the legs worsened. Despite the severe coagulation abnormalities, vascular interventions should have been performed with regular-dose antiplatelet therapy, as the patient exhibited multiple risk factors for atherothrombosis.
KeywordsAnti-factor V autoantibody Bleeding/hemorrhage Thrombosis False multiple factor deficiencies False multiple factor inhibitors
This study was supported in part by research aids from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japanese Ministry of Health, Labor and Welfare (MHLW), and a research gran from Japan Agency for Medical Research and Development (AMED). We would like to thank all members of ‘Japanese Collaborative Research Group (JCRG) on Autoimmune Coagulation Factor Deficiencies’ and Ms. Yuriko Shibue and Ms. Eiko Ichinose for their cooperation in conducting a nation-wide survey in Japan from 2009 to 2018.
HO carried out clinical studies and drafted the manuscript, MS, KK and TO performed experimental laboratory examinations and analyzed the results, SO, TK, and SW collected clinical data, KM reviewed the project and the manuscript, and AI designed the project and experiments, analyzed the results and wrote the manuscript. All authors have approved the submitted version.
Compliance with ethical standards
Conflict of interest
The authors declare no conflicts of interests in association with this study.