Remarkable Prolongation of Irreversible APTT and Non‐Significant Hemorrhage: A Rare High Titer of FVIII Inhibitor Case Report and Literature Review

BACKGROUND: Acquired hemophilia A (AHA) is a rare hemorrhagic disease characterized by isolated prolongation of activated partial thromboplastin time (aPTT) and existence of autoantibodies against factor VIII (FVIII). METHODS: Here, we present a patient with subcutaneous hemorrhage and remarkable prolongation of irreversible aPTT. RESULTS: Further laboratory testing revealed reduced activity of multiple coagulation factors; this finding was subsequently identified as an artifact caused by the high-titer FVIII inhibitor, confirmed through dilution studies. Despite the high inhibitor titer and the presence of bleeding manifestations, specific anti-hemorrhagic therapy was not required for this patient. Following 6 months of immunosuppressive treatment, the patient achieved resolution of ecchymosis and maintained normal coagulation factor activity. Throughout the 12-month follow-up period, the patient ultimately died from disease progression under palliative support. CONCLUSION: In all, this study demonstrated atypical characteristics of an AHA patient and emphasized that the treatment strategy should be guided by clinical manifestation rather than testing results solely.