Effect of low-dose factor VIII prophylaxis therapy on bone mineral density and 25(OH) vitamin D level in children with severe haemophilia A.

Abstract

Decreased bone mineral density (BMD) is a significant morbidity in haemophilia. Vitamin D is important for the bone health of people with haemophilia. Regular factor VIII prophylaxis can prevent bleeding and arthropathy. To determine the 25(OH) vitamin D level in severe haemophilia A patients and correlate it to their Hemophilia Joint Health Score (HJHS) and dual-energy X-ray absorptiometry (DEXA). We also compared the 25(OH) vitamin D and DEXA in haemophilia A and healthy children and in haemophilia A children on prophylaxis versus on-demand therapy. Fifty severe haemophilia A patients were compared to 50 age-matched healthy boys. Patients were recruited from the Pediatric Hematology Clinic, Ain Shams University from May 2017 to April 2018. Full medical history was taken with emphasis on frequency of bleeding episodes, duration and amplitude of pain assessed by the pain score. Weight, height, body mass index and HJHS were assessed. 25(OH) vit-D3, calcium, phosphorus and alkaline phosphatase were measured. BMD was assessed using Lunar DEXA, paediatric software. People with haemophilia had significantly lower 25(OH) vit-D3 (P<.001) and DEXA z-score (P<.001) than controls. Seventy per cent of patients were on factor VIII prophylaxis twice weekly (15U/kg/dose). Significant difference was found regarding DEXA z-score (P=.012), 25(OH) vit-D3 (P=.033) and HJHS (P=.022) among patients on prophylaxis and on-demand therapy. Severe haemophilia A patients showed significantly lower 25(OH) vit-D3 and DEXA than controls. Hence, vitamin D deficiency should be tested in all people with haemophilia for early diagnosis and treatment. Low-dose prophylaxis in severe haemophilia preserves BMD and increases vitamin D. Further studies are required to evaluate the effect of different prophylaxis protocols on BMD and haemophilic arthropathy.