The effect of uricase on monosodium urate (MSU) crystallization, IL-1β and TNFα in monosodium urate-induced arthritis

Background: Although the symptoms of gouty arthritis could be controlled by clinical methods, it is often impossible to remove tophi from joints that cause acute gouty arthritis. Methods : In study, we injected a suspension of MSU into the knee joint of chicken, and then injected uricase solution into the joint after 4, 8 and 12 hours. Since the beginning of the experiment, we monitored the circumference of the diseased joint and local temperature change. Computer tomography(CT) examination was performed to examine the MSU in the knee joints and then measured the levels of TNFα and IL-1β in synovial fluid. Chicken knee joint fluid was collected under polarized light microscope to observe the condition of the crystals and measured the weight of MSU residued in synovial fluid. Finally, the chicken knee joint was dissected and the joint synovium was sliced. Results : The results showed that injection of MSU suspension into chicken knee joint, significantly increased IL-1β, TNFα levels (p<0.01), circumference of the joint (p<0.05) and the local skin temperature (p<0.05). Moreover, analysis of the joint fluid and synovial slice under the polarized light microscope revealed that crystals significantly reduced. Compared with groupⅡ(control group), the residual weight of MSU in the joint fluid of group Ⅲ and group Ⅳ is very small(p<0.05), but there is no significant difference between group Ⅲ and group Ⅳ(p＞0.05). Conclusions : The comprehensive analysis shows that the reaction process between uricase and MSU is similar to that uric acid. Therefore, it provides a new way for clinical treatment of acute gouty arthritis with fewer side effects and significant reduction in the frequency of attacks.