A single intra-articular injection with IL-4 plus IL-10 ameliorates blood-induced cartilage degeneration in haemophilic mice.

The combination of interleukin (IL)-4 and IL-10 protects against blood-induced cartilage damage in vitro. It has been hypothesized that the combination of these cytokines is effective if applied early in the process of cartilage damage. The present study investigated whether a single intra-articular injection of IL-4 plus IL-10 immediately after a joint bleed limits cartilage damage in an in vivo haemophilia mouse model of blood-induced joint damage. Factor VIII knockout mice with severe haemophilia A were punctured once with a needle below the patella to induce a joint haemorrhage. Subsequently IL-4 plus IL-10 (n = 24) or vehicle (n = 24) was injected intra-articularly. After 35 days, the time needed for development of detectable joint degeneration, knee joints were examined for cartilage damage by macroscopic and microscopic evaluation. A single intra-articular injection of IL-4 plus IL-10 ameliorated progression of cartilage degeneration caused by a single joint bleed to a certain extent. No effect on inflammation was observed at this time point. A single intra-articular injection of IL-4 plus Il-10 directly after a single joint bleed limits progression of cartilage degeneration over time. Improved bioavailability (half-life) of both cytokines might improve their protective ability in the development of cartilage degeneration, and probably also inflammation.

A short time window to profit from protection of blood-induced cartilage damage by IL-4 plus IL-10.

OBJECTIVE: IL-4 plus IL-10 prevents blood-induced cartilage damage. The aim of the present study was to evaluate whether cartilage damage can still be averted by addition of IL-4 plus IL-10 when added after the onset of a bleed and whether aspiration of blood prior to addition of IL-4 plus IL-10 is of additive protective value. METHODS: Healthy canine hip and human shoulder cartilage was exposed to whole blood for 4 days. IL-4 plus IL-10 was administered directly or after a delay of several hours up to 2 days. Furthermore, blood was aspirated after 1 or 2 days and subsequently IL-4 plus IL-10 was added. IL-1ß concentration and cartilage matrix proteoglycan turnover were determined. RESULTS: Exposure of canine and human cartilage to blood decreased the proteoglycan synthesis rate and content and increased proteoglycan release. IL-4 plus IL-10 only prevented blood-induced damage of canine cartilage when added directly, not after 4 h or later. For human cartilage, IL-4 plus IL-10 limited blood-induced damage as well as IL-1ß production when administered within 4-8 h after the onset of a bleed, but not thereafter. Aspiration of blood within 24 h fully prevented cartilage damage. Subsequent addition of IL-4 plus IL-10 was not of additive value. CONCLUSION: For humans, there is a short time window after onset of a joint bleed in which IL-4 plus IL-10 can limit blood-induced cartilage damage. Furthermore, aspiration of a joint to shorten blood exposure fully prevents cartilage damage. Both options can be considered in the treatment of a joint haemorrhage.

Coagulation aggravates blood-induced joint damage in dogs.

OBJECTIVE: Joint bleeding due to trauma, major joint surgery, or hemophilia leads to joint damage. It is unclear if there are differences between coagulating blood and anticoagulated blood with respect to joint degeneration, especially in vivo. Therefore, we undertook this study to evaluate in a canine in vivo model whether intraarticular exposure to coagulating blood is more destructive than exposure to anticoagulated blood, and whether inflammation plays a role in the cartilage- damaging process. METHODS: In 7 dogs the left knees were injected with coagulating blood 4 times a week during weeks 1 and 4, and the right knees were injected with saline. In 7 other dogs, anticoagulated heparinized blood was injected, and heparinized saline was used as control. Ten weeks after the last injection, cartilage matrix turnover and synovial inflammation were analyzed. To study inflammation-independent cartilage damage, explants of cartilage from at least 6 human donors per group were exposed in vitro to coagulating and anticoagulated blood, plasma, and serum for 4 days. Cartilage matrix turnover was determined after a recovery period of 12 days. RESULTS: Canine knees injected with coagulating blood showed more disturbed proteoglycan turnover than knees injected with anticoagulated blood. Synovial inflammation was present only after intraarticular injections with coagulating blood. In in vitro experiments, exposure of human cartilage explants to coagulating blood resulted in more damage than did exposure to anticoagulated blood, while exposure to plasma and serum did not alter cartilage matrix turnover. CONCLUSION: This study shows that coagulating blood causes more long-lasting in vivo joint damage than anticoagulated blood, thereby suggesting that along with joint bleeding in hemophilia, exposure to intraarticular blood should also be avoided during surgery and trauma to prevent joint damage.

Blood-Induced Joint Damage: The Devastating Effects of Acute Joint Bleeds versus Micro-Bleeds.

OBJECTIVE: Four days of blood exposure leads to irreversible cartilage damage in vitro. In contrast, intermittent intra-articular blood injections twice a week during 4 weeks (mimicking micro-bleeds) in a canine model resulted in transient damage only. In this study, it was evaluated whether acute joint bleeds are more harmful than micro-bleeds in a canine model of knee arthropathy. DESIGN: Seven dogs received 4 sequential daily intra-articular blood injections twice in 2 weeks (mimicking 2 acute 4-day joint bleeds). Seven other dogs received the same blood load but in a total of 8 injections intermittently over the 4-week period with at least 1 day in between (mimicking micro-bleeds over the same timespan). Contralateral knees served as controls. Ten weeks after the last injection cartilage matrix turnover and synovial inflammation were evaluated. RESULTS: Only after the acute joint bleeds the release of newly formed and total (resident) cartilage matrix glycosaminoglycans were increased (P = 0.04 and P = 0.01, respectively). Furthermore, in animals with the acute joint bleeds cartilage glycosaminoglycan content was decreased (P = 0.01) and not in animals with micro-bleeds. Mild synovial inflammation was observed in both groups (both P < 0.0001) but was not different between groups. CONCLUSIONS: In contrast to micro-bleeds, 2 acute joint bleeds lead to prolonged cartilage damage independent of the level of synovial inflammation. This model suggests that micro-bleeds are less devastating than acute joint bleeds with respect to joint damage, which might be of relevance to treatment of joint bleeds in clinical practice.