Prevention of arthropathy: may it be extrapolated from patients without inhibitors to patients with inhibitors?

Although no consensus on the exact dosing schedule of prophylaxis in non-inhibitor haemophilia patients has been achieved, regular administration of factor VIII (FVIII) or factor IX (FIX) concentrates is currently accepted as the most effective treatment model in order to prevent sick days, hospital stays and the development of arthropathy in patients with severe haemophilia. The basis for prophylaxis has been the idea to increase the plasma levels of FVIII or FIX above 1% thereby improving the haemostasis in severe haemophilia. Current treatment in haemophilia patients with inhibitors includes the use of activated prothrombin complex concentrates and recombinant FVIIa (rFVIIa). Regular administration of such agents has recently repeatedly been reported to decrease the number of joint and muscle bleeds in these patients. Regarding rFVIIa, such an effect was confirmed in a controlled study published in 2007. Although the exact mechanism of action of rFVIIa in this setting is still not clear, it seems reasonable to assume that prophylaxis with rFVIIa will be able to prevent or minimize the development of haemophilic arthropathy. As arthropathy is a long-term complication in haemophilia and the result of repeated joint bleeds, a longer follow-up of patients on regular prophylaxis including measurements of the joint scores, as has been performed in FVIII/FIX prophylaxis in non-inhibitor patients, will be required for a definite conclusion.