Magnetic resonance imaging evidence for subclinical joint bleeding in a Dutch population of people with severe hemophilia on prophylaxis

Background: Previous studies suggest that subclinical bleeding occurs in persons with hemophilia.Objectives: The aim of this study was to investigate whether patients with lifelong access to prophylaxis showed signs of previous subclinical bleeding on magnetic resonance imaging (MRI) in joints without a history of joint bleeding.Methods: This single-center cross-sectional study included persons with severe he-mophilia A on prophylaxis, aged 16 to 33 years, with lifetime bleeding records available. Per participant, 1 index joint without a history of joint bleeding was evaluated with 3-Tesla MRI, including hemosiderin sensitive sequences. MRI scans were reviewed according to the International Prophylaxis Study Group (IPSG) additive MRI scale (range, 0-17/joint). Hemosiderin deposits with/without synovial hypertrophy were considered signs of previous subclinical bleeding. Additionally, physical examination was performed, followed by ultrasound examination according to the Hemophilia Early Arthropathy Detection with Ultrasound protocol. Results: In 43 patients with a median age of 23.5 years, 43 joints (16 elbows, 13 knees, 14 ankles) without reported bleeds were evaluated with MRI. The median IPSG MRI score was 1 (range, 0-9). Signs of previous subclinical bleeding were observed in 7 of 43 joints (16%; 95% CI, 7-30): 7 of 7 joints showed hemosiderin deposits, with concomitant synovial hypertrophy in 2 of 7 joints. MRI changes were accompanied by swelling and ultrasound-detected synovial hypertrophy in 1 ankle only. None of the other joints showed abnormalities at physical examination and ultrasound.Conclusion: In this study, 16% of the joints without reported bleeds showed signs of previous subclinical bleeding, providing evidence for subclinical bleeding in people with severe hemophilia with lifelong access to prophylaxis.