Factor X Concentrate Treatment Schedule and Dosing in Acquired FX Deficiency

Abstract

Background: Acquired factor X (FX) deficiency is a rare condition that can cause life threatening bleeding. Here we outline a successful management strategy for gastrointestinal bleeding (GI) using human FX concentrate.

Case description: A 61-year-old male presented with upper GI bleeding and a prolonged prothrombin time. Investigations demonstrated an acquired FX deficiency (determined to be secondary to AL amyloidosis).

Results: Treatment with FX concentrate to maintain trough FX levels >20% resulted in successful cessation of bleeding symptoms, and levels >50% facilitated urgent invasive procedures.

Conclusions: This case report adds valuable insight into the management of this rare condition, and how best to utilize FX concentrates in acquired FX deficiency.

Keywords: Coagadex; amyloidosis; factor X.

Figure 1

Trends in FX activity throughout hospital admission. Showing factor X level (%) at different time points during admission, pre- and post-FX concentrate treatment. FX concentrate was initially dosed at [body weight × desired factor 10 rise × 0.5]. Doses were increased by 100% until the desired factor X levels were achieved. Maintaining peak and trough factor X levels above 20% (blue line) resulted in significant improvement in bleeding episodes (denoted by red triangles). A threshold of 50% was used to facilitate interventions (green line), with no post-procedural haemorrhage reported.

Figure 2

Congo red stain of gastric biopsy. Gastric biopsy from patient with Congo red stain showing apple green bi-refringence, diagnostic of amyloid infiltration.