Bleeding outcomes and factor utilization after switching to an extended half-life product for prophylaxis in haemophilia A in Austria.

To prevent bleeding in severe haemophilia A [SHA, defined as factor VIII (FVIII) activity < 1%] regular prophylactic FVIII replacement therapy is required, and the benefits of factor products with extended half-life (EHL) over traditional standard half-life (SHL) are still being debated. We performed a multi-centre, retrospective cohort study of persons with SHA in Austria aiming to compare clinical outcomes and factor utilization in patients with SHA, who switched from prophylaxis with SHL to an EHL. Data were collected from haemophilia-specific patient diaries and medical records. Twenty male persons with SHA (median age: 32.5 years) were included. The most common reason for switching to the EHL was a high bleeding rate with SHL. Switch to rFVIII-Fc resulted in a significantly decreased annualized bleeding rate (ABR; median difference (IQR): - 0.3 (- 4.5-0); Wilcoxon signed-rank test for matched pairs: Z = - 2.7, p = 0.008) and number of prophylactic infusions per week (- 0.75 (- 1.0-0.0); Z = - 2.7, p = 0.007). Factor utilization was comparable to prior prophylaxis with SHL (0.0 (- 15.8-24.8) IU/kg/week; Z = - 0.4, p = 0.691). In summary, switch to EHL (rFVIII-Fc) was associated with an improved clinical outcome, reflected by ABR reduction, and less frequent infusions, without significantly higher factor usage.

Long-term follow-up after successful treatment of vaccine-induced prothrombotic immune thrombocytopenia.

BACKGROUND: Cases of ChAdOx1 nCoV-19 (AstraZeneca) vaccinated patients with thrombocytopenia, elevated D-dimer, and elevated platelet factor 4 (PF4) antibody levels with- and without thrombosis have been reported. No recommendations regarding the duration of anticoagulation have been made, because data on the long-term course beyond the first weeks is lacking. OBJECTIVE: To report on the treatment, medical course, and longitudinal follow-up of laboratory parameters in patients with vaccine-induced prothrombotic immune thrombocytopenia (VIPIT). PATIENTS: We followed VIPIT patients with- (n = 3) and without (n = 3) venous thromboembolism fulfilling the aforementioned laboratory criteria. RESULTS: Elevated D-dimer (median: 35.10 µg/ml, range: 17.80-52.70), thrombocytopenia (42 G/l, 20-101), and strong positivity in the platelet factor 4 (PF4)/heparin-enzyme-immunoassay (2.42 optical density [OD], 2.06-3.13; reference range < 0.50) were present in all patients after vaccination (10 days, 7-17). Routine laboratory parameters rapidly improved upon initiation of treatment (comprising therapeutic non-heparin anticoagulation in all patients and high dose immunoglobulins ± corticosteroids in 5 patients). PF4 antibody levels slowly decreased over several weeks. Patients were discharged in good physical health (8 days, 5-13). VIPIT did not recur during follow-up (12 weeks, 8-17). Five of 6 patients fully recovered (in 2 patients thrombosis had resolved, in 1 patient exertional dyspnea persisted). CONCLUSIONS: Remissions without sequelae can be achieved upon rapid initiation of treatment in patients with VIPIT. Platelet factor 4 antibody levels slowly decreased over several weeks but VIPIT did not recur in any of our patients. Continuation of anticoagulation in VIPIT patients at least until PF4 antibody negativity is reached seems reasonable.