Key result
A 75-year-old man on rivaroxaban presented with severe bleeding and a significantly elevated PTT, leading to the rare diagnosis of an acquired factor VIII inhibitor.
Why the study?
Reports of DOAC use and concomitant factor inhibitor autoimmunization are scarcely explored in the existing literature, and variable DOAC effects on PT and PTT make superimposed bleeding disorders difficult to detect.
Case Report (n=1)
Direct oral anticoagulant use can complicate and delay the diagnosis of superimposed bleeding disorders, such as acquired factor VIII inhibitors, due to their variable effects on coagulation assays.
Acquired factor VIII inhibitor should be considered in rivaroxaban patients with bleeding and elevated PTT; single case leaves any causal link open.
Direct oral anticoagulants (DOACs) are used to treat several conditions such as non-valvular atrial fibrillation, deep vein thrombosis, and pulmonary embolism. DOACs and other anticoagulants block crucial steps in the coagulation cascade and ultimately prevent clot formation. Generally, individuals initiated on an anticoagulant are predisposed to or have a propensity to form clots. Patients with hemophilia are given anticoagulants only in very rare cases. In this report, we discuss the case of a 75-year-old man with a history of atrial fibrillation managed on rivaroxaban; he presented to the emergency department with fatigue, easy bleeding, symptomatic anemia, and significantly elevated partial thromboplastin time (PTT) with an undiagnosed acquired factor VIII inhibitor. Reports of DOAC use and concomitant factor inhibitor autoimmunization, as seen in this case, are scarcely explored in the existing literature. While DOACs are popular anticoagulants, their variable effects on both prothrombin time (PT) and PTT make it difficult to detect superimposed bleeding disorders. In patients with severe anemia or significant elevations in PT or PTT, an expedited workup, including factor assays, may be a reasonable option as evidenced by this case.
No takes yet. Share an insight, caveat, or question.
Gutierrez et al. (2021) conducted a case report in Acquired factor VIII inhibitor (n=1). Rivaroxaban was evaluated. A 75-year-old man on rivaroxaban presented with severe bleeding and a significantly elevated PTT, leading to the rare diagnosis of an acquired factor VIII inhibitor.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:
More from Cureus