Minimal factor XIII activity level to prevent major spontaneous bleeds

Area of Science:

• Hematology
• Rare bleeding disorders
• Coagulation factor deficiencies

Background:

• Congenital factor XIII (FXIII) deficiency is a rare bleeding disorder with significant bleeding manifestations.
• Previous studies, including the EN-RBD study, demonstrated a strong link between FXIII activity levels and bleeding severity.
• Patients exhibit a wide range of FXIII activity, correlating with diverse bleeding severities.

Purpose of the Study:

• To confirm the association between FXIII coagulant activity and clinical bleeding severity in patients with FXIII deficiency.
• To identify a specific FXIII activity threshold for initiating prophylactic treatment.
• To inform prophylaxis strategies for preventing major bleeding in FXIII-deficient individuals.

Main Methods:

• A cross-sectional analysis of data from 64 patients with FXIII deficiency.
• Prospective cohort study design within the PRO-RBDD project.
• Evaluation of clinical and laboratory severity markers in relation to FXIII activity levels.

Main Results:

• FXIII coagulant activity in plasma strongly correlates with the clinical severity of bleeding in patients.
• A FXIII activity level of 15 IU dL^-1 was identified as a critical threshold.
• Below 15 IU dL^-1, the probability of spontaneous major bleeding significantly increases, reaching over 90% at 5 IU dL^-1 or lower.

Conclusions:

• The PRO-RBDD study reinforces the association between FXIII activity and bleeding severity.
• A target FXIII coagulant activity level of 15 IU dL^-1 is suggested for initiating prophylaxis.
• This target aims to prevent severe bleeding complications, including CNS and gastrointestinal hemorrhages.