Life-threatening bleeding tendency provoked by an acquired isolated factor X deficiency associated with respiratory infection

摘要

Dear Editor, Acquired factor X deficiencies (FXD) are common in the setting of vitamin K deficiency, vitamin K antagonist therapy, or liver disease. Isolated acquired FXD is rare and predominantly described with monoclonal immunoglobulin deposition diseases due to direct factor X binding to amyloid fibrils [1]. Other associated diseases include myeloma, acute leukemia, and solid tumors [2]. Since 1965, there are as few as 34 cases reporting isolated acquired FXD in the absence of amyloidosis or plasma cell dyscrasia [3].