Plasma-derived Factor X Therapy for Treatment of Intracranial Bleeding in a Patient with Factor X Deficiency: A Case Report

Scientific Research Question: Factor X (FX) deficiency is an extremely rare autosomal recessive hereditary hematologic disorder, affecting approximately 1:1,000,000 of the general population. This case report describes an infant with hereditary severe FX deficiency who presented with a spontaneous, life-threatening intracranial hemorrhage and was treated with the first licensed plasma-derived FX (pdFX) concentrate.

Methodology: A 4-month-old female infant (the index patient) presented at a pediatric clinic based on 2 days of vomiting and acute vigilance decrement. Cranial ultrasonography showed a mass with pronounced midline displacement to the right. The infant was transferred to our pediatric hospital, where neurosurgical intervention included hematoma relief with rinsing and installation of subdural cortex drainage. Laboratory assays showed severe coagulopathy of unknown cause; the patient was empirically treated using a multimodal hemostatic approach with prothrombin complex concentrate, fresh-frozen plasma, and tranexamic acid. A one-stage coagulation assay was used to evaluate single-factor activity. Mutation screening for FX deficiency was performed by Sanger sequencing.

Findings: On admission, laboratory tests showed a prolonged international normalized ratio (INR) of 14.55 and an activated partial thromboplastin time (aPTT) of 75.8 seconds. Following initial hemostatic treatment, laboratory tests showed an improved INR of 0.98 and aPTT of 44.2 seconds. A one-stage coagulation assay revealed severe FX deficiency with FX:C levels < 1% at admission; all other coagulation factors were within normal range. Mutation screening revealed a homozygous missense mutation within the F10 gene. Treatment was changed to a targeted regimen of pdFX 250 IU daily. Based on careful monitoring of the coagulation profile, pdFX administration frequency was increased to twice daily, followed by a reduction to once every 18 hours, after which trough plasma concentrations were >50%. Magnetic resonance imaging 1 month after the initial event showed no rebleeding and resorption of the residual blood. The patient was discharged after 7 weeks of hospitalization in good clinical condition and now receives prophylactic pdFX three times weekly, maintaining a trough plasma FX concentration of approximately 5%. Throughout the treatment course, pdFX has been well tolerated, and no adverse events have been observed.

Conclusions: Single-factor therapy with pdFX was effective and well tolerated in treating an infant with severe hereditary FXD who presented with ICH without potential thromboembolic complications.

Funding: Bio Products Laboratory

No conflict of interest has been declared by the author(s).