Utility of factor X concentrate for the treatment of acquired factor X deficiency in systemic light-chain amyloidosis.

To the editor: Coagulation abnormalities are frequent in systemic light-chain (AL) amyloidosis,[1][1] 6.3% to 14% present with acquired factor X (FX) deficiency reported,[1][1][⇓][2]-[3][3] with baseline FX levels not predictive of bleeding risk.[4][4] Rapid clearance of 131I-labeled FX from the