A Retrospective Review Of Factor X Levels and Bleeding Risk In Patients With Amyloidosis

Bleeding is a common presentation of light chain AL amyloidosis mainly attributable to vascular fragility and impaired vasoconstriction also known as Amyloid Angiopathy. It has also been shown that acquired coagulation factor deficiencies such as Factor X can exacerbate this situation and can be the leading cause of mortality in these patients. We performed a retrospective review of Bleeding disorders in patients with AL amyloid from the Amyloid Database at The Houston Methodist Hospital between 2006 and 2013.

We performed a retrospective review extracting information from the Tumor Registry and the Medical Electronic Records by querying for the diagnosis of Amyloidosis. We obtained baseline demographics, laboratory data, diagnostic workup, treatment plan including bone marrow, Lung and Heart transplant, clinically documented bleeding events and overall outcomes.

We reviewed 411 patients who met the inclusion criteria. At the time of review, Amyloid typing was available in 95 patients out of which 85 were Al Amyloid. The baseline demographics included 213 males and 198 females, whose median age was 67; 238 were Caucasians while 77 were African Americans, 34 Hispanic, 12 Asian and 49 reportedly as others. Since the primary end point was review of bleeding, we sorted the groups based on the events into bleeders requiring ICU admission, bleeders without ICU admission and the non-bleeders. As shown in Figure 1, bleeders with ICU admission were 16 patients with a median PT of 19.77, median INR 1.6 and a low median factor X assay of 45% (range 70-120); Median BNP was 1285, serum creatinine 1.5, platelets 133, and Fibrinogen 356. From this group only 1 patient received a Heart and Lung Transplant.

In the group of bleeders not requiring ICU admission there were 50 patients with a median PT of 16.2, median INR 1.128 and a low median factor X assay of 76%. Median BNP was 795 serum creatinine 1.37, platelets 126, and Fibrinogen 403.5. In this cohort 7 received bone marrow transplants, 3 received both Heart and Bone Marrow Transplants.

In the group of nonbleeders, we had a total of 340 patients with a median PT of 15.7, median INR 1.2 and a low median factor X assay of 66. Median BNP was 240, serum creatinine 1.3, platelets 173, and Fibrinogen 409. In this cohort 16 received Bone Marrow transplant, 1 received lung Transplant and 10 received Heart Transplant.

Even though Amyloid Angiopathy is a major cause of bleeding, acquired factor X deficiency could potentially be reversible. There are reports of no correlation of diminished Factor X activity and severity of bleeding. Our data indicates that patients with very low factor X deficiency have a high risk of bleeding potentially requiring critical care support. Further statistical review of this data set will be presented at the American Society of Hematology, New Orleans 2013.

No relevant conflicts of interest to declare.