Deferasirox limits cartilage damage following haemarthrosis in haemophilic mice.

Joint bleeds in haemophilia result in iron-mediated synovitis and cartilage damage. It was evaluated whether deferasirox, an iron chelator, was able to limit the development of haemophilic synovitis and cartilage damage. Haemophilic mice were randomly assigned to oral treatment with deferasirox (30 mg/kg) or its vehicle (control) (30 mg/kg). Eight weeks after start of treatment, haemarthrosis was induced. After another five weeks of treatment, blood-induced synovitis and cartilage damage were determined. Treatment with deferasirox resulted in a statistically significant (p< 0.01) decrease in plasma ferritin levels as compared to the control group (823 ng/ml ± 56 and 1220 ng/ml ±114, respectively). Signs of haemophilic synovitis, as assessed by the Valentino score [range 0 (normal) - 10 (most affected)], were not different (p=0.52) when comparing the control group with the deferasirox group. However, deferasirox treatment resulted in a statistically significant (p< 0.01) reduction in cartilage damage, as assessed by the loss in Safranin O staining [range 0 (normal) - 6 (most affected)], when comparing the deferasirox group with the control group: score 2 (65.4 % vs 4.2 %), score 3 (26.9 % vs 4.2 %), score 4 (7.7 % vs 20.8 %), score 5 (0 % vs 54.2 %), and score 6 (0 % vs 16.7 %). Treatment with deferasirox limits cartilage damage following the induction of a haemarthrosis in haemophilic mice. This study demonstrates the role of iron in blood-induced cartilage damage. Moreover, these data indicate that iron chelation may be a potential prevention option to limit the development of haemophilic arthropathy.

Interleukin-10 protects against blood-induced joint damage.

Despite prophylactic treatment, haemophilia patients suffer from spontaneous joint bleeds, which lead to severe joint damage. Also after joint trauma, an intra-articular haemorrhage can add to joint damage over time. This study evaluated interleukin 10 (IL-10) in the search for possible interventions to prevent or limit the damaging effects of joint bleeds. Human articular cartilage tissue explants were cultured in the presence or absence of 50% v/v blood (or its cellular components) for 4 d (the expected blood load in vivo after a joint haemorrhage), followed by a recovery period of 12 d. Pharmacological dosages of IL-10 reached during treatment (1 or 10 ng/ml) were added. Additionally, cartilage and synovial tissue obtained from joints with end-stage haemophilic arthropathy (HA) were cultured in the presence of IL-10 (10 ng/ml). IL-10 protected cartilage from the damaging effects of blood exposure, measured by its effects on proteoglycan turnover. In addition, IL-10 beneficially influenced cartilage from patients with HA and reduced the production of the inflammatory cytokines IL-1beta and tumour necrosis factor-alpha by haemophilic synovial tissue. Taken together, although effects were obtained in vitro, IL-10 protects against blood-induced joint damage and might be further evaluated as candidate in treatment of tissue damaging effects of joint haemorrhages.