LongHest project: A prospective, observational study of extended half-life treatment in the musculoskeletal health of patients with severe haemophilia A.

Background: Prophylactic treatment is the gold standard in the treatment of patients with haemophilia. Prophylaxis with extended half-life (EHL) treatment has shown long-term safety and efficacy in patients with haemophilia.

Aim: To evaluate the efficacy of prophylaxis with EHL treatment in the frequency of haemarthrosis and musculoskeletal health in adult patients with severe haemophilia A.

Methods: Prospective cohort study. Forty-six patients with severe haemophilia A were recruited. The frequency of haemarthrosis (self-reports), joint condition (Haemophilia Joint Health Score), pain intensity (visual analogue scale), range of motion (goniometry), and strength (dynamometry) and muscle activation (surface electromyography) were evaluated. Three assessments were carried out: at baseline (T0), at 6 months (T1) and at 12 months following treatment (T2).

Results: There were significant changes in the within-subject effect in the frequency of haemarthrosis in elbow (F(1.05;96.20) = 3.95; P < .001) and knee (F(1.73;157.99) = 9.96; P < .001). Significant within-subject effect in elbow pain intensity (F(2;182) = 63.51; P < .001) was found. The mean values of the frequency haemarthrosis in elbow (from .66±1.01 to .04±.20) and knees (from .55±.68 to .33±.53) decrease after the period study. The intensity of elbow pain and (from 3.08±1.69 to 2.67±1.73), decrease after the 12-month follow-up period.

Conclusions: Prophylaxis with extended half-life treatment reduces the frequency of haemarthrosis in elbow and knee in adult patients with haemophilia. EHL treatment reduces the intensity of elbow pain in patients with haemophilic arthropathy.