Abstract Number: PB1195
Meeting: ISTH 2020 Congress
Background: Hereditary factor X (FX) deficiency (FXD) is a rare autosomal recessive bleeding disorder resulting in reduced plasma FX coagulant activity (FX:C). FXD patients with FX:C < 1% generally have severe bleeding symptoms, but patients with higher FX:C may also exhibit serious bleeding. Mild/moderate FXD is presumed to be less severe, but the heterogeneity of clinical features may result in delayed recognition and management. There are few reports and no evidence-based guidelines for management of these patients.
Aims: To characterize diagnostic features, evaluate bleeding patterns, and assess current management strategies for patients with mild/moderate FXD.
Methods: This retrospective chart review included patients with FX:C ≥1% managed at 2 hemophilia treatment centers (HTCs) in the United States. Expansion to other HTCs is planned.
Results: Five patients were included: 2 siblings aged < 1 year and 3 years, and 3 unrelated patients aged 16, 17, and 20 years at the time of analyses (Table). Three of the five patients were identified due to a hemorrhage; two were identified based on family history of FXD. Two patients with heavy menstrual bleeding (HMB) received antifibrinolytics, iron replacement and hormonal therapy for HMB management. An intracranial hemorrhage was treated with prothrombin complex concentrates until bleed resolution (30 doses), and 3 bleeds (2 external ear trauma, 1 gum biopsy) in one patient were treated with plasma-derived FX concentrate (1 dose per bleed). All bleeds were deemed to have a fair to good response with first-line therapy. One patient did not experience any bleeds requiring treatment (FX:C 52%).
Conclusions: Hereditary FXD is a heterogenous disorder with variable bleeding phenotype. The association between the bleeding phenotype and laboratory results is essential for establishing the appropriate diagnosis. Evaluation of additional patients with mild/moderate FXD will provide information about the bleeding manifestations and response to therapy, allowing formulation of clinical management guidelines.
|Table. Patient Characteristics and Diagnostic Laboratory Results|
|PT, sec||PTT, sec||FX:C, %|
|Patient no.||Age at analysis, y||Presenting complaint||Test result||Normal range||Test result||Normal range||Test result||Normal range||FX antigen, %|
|1||<1||Family history||21.3||9.8 – 13.1||118.2||27.0 – 36.3||7.4||50 – 150||89|
|2||3||Intracranial hemorrhage after a fall||26.3||9.8 – 13.1||99.5||27.5 – 37.4||8||50 – 150||82|
|3||16||HMB||13.5||9.4 – 11.7||29.0||23.1 – 33.1||36||64 – 144||Pending|
|4||17||Epistaxis||13.3||9.4 – 11.7||39.0||23.1 – 33.1||48||64 – 144||78|
|5||20||Family history||12.0||9.4 – 11.7||30.4||23.1 – 33.1||52||64 – 144||43|
|PT=prothrombin time; PTT=partial thromboplastin time.|
[Patient characteristics and diagnostic laboratory results]
To cite this abstract in AMA style:Acharya S, Sabo C, Chitlur M. Characterization and Management of Patients with Mild or Moderate Hereditary Factor X Deficiency: A Retrospective Chart Review [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/characterization-and-management-of-patients-with-mild-or-moderate-hereditary-factor-x-deficiency-a-retrospective-chart-review/. Accessed January 23, 2022.
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