Factor‐X deficiency in amyloidosis: A critical review

Abstract

Thirty cases of amyloidosis with factor-X deficiency, including six of our own, were reviewed. Modest deficiency of factor X was often associated with severe bleeding. In many of the cases, clinical bleeding could not be accounted for by deficiency of factor X alone. Other hemostatic defects were found in these patients and probably contributed to the bleeding. Modes of treatment, including the empiric use of corticosteroids and splenectomy, were discussed in light of current knowledge of pathogenesis of this unusual blood clotting disorder. This involves the interaction of amyloid fibrils and blood clotting factors.

Direct Factor X sequestration by systemic amyloid light‐chain amyloidosis

“…Six to fourteen percent of AL amyloidosis patients develop an acquired Factor X (FX) deficiency 3, 4, 5. The direct binding/adsorption of FX onto amyloid fibrils has been thought to be a major mechanism for FX deficiency in amyloidosis.…”

Coagulopathy in a patient with nephrotic syndrome

“…In contrast, heparin or direct thrombin inhibitors such as argatroban, hirudin, and bivalirudin prolong the thrombin time but not the reptilase time. The data were pooled from the results published in five cohort series [4][5][6][7][8].…”

“…Five cohort series of patients with systemic amyloidosis were found using Medline search [4][5][6][7][8], and the number of patients with abnormal coagulation tests were pooled (Table I). Prolonged thrombin clotting times and reptilase times are the most common coagulation abnormalities in AL-amyloidosis [4,6].…”

Spontaneous rupture of the spleen in AL amyloidosis

“…reported series that have indicated Factor X deficiency in 6.3-14% of patients [26,32]. In our experience, 75% of patients with severe Factor X deficiency had hemorrhagic complications, of which 50% were severe and 17% fatal.…”