The influence of proteolytic-antiproteolytic enzymes and prooxidative-anti-oxidative factors on proteoglycan alterations in children with juvenile idiopathic arthritis (JIA) was evaluated in this study.
Plasma and urinary glycosaminoglycans (GAGs), as well as plasma levels of matrix metalloproteinases (MMPs) (MMP-3, MMP-10), tissue inhibitors of metalloproteinases (TIMPs) (TIMP-1, TIMP-2), total oxidative status (TOS) and total antioxidative status (TAS), were quantified in samples obtained from 30 healthy subjects and 30 JIA patients before and after treatment. Significantly decreased plasma and urinary concentration of GAGs in JIA patients before treatment was observed. Therapy resulted in an increase in the concentration of the above listed parameters. However, the plasma GAG level still remained significantly lower compared to that in controls. Increased levels of MMP-3 and TIMP-1 in both JIA patient groups were recorded. The plasma MMP-10 and TIMP-2 concentrations in untreated patients were significantly decreased. Anti-inflammatory treatment led to normalization of these parameter concentrations. Significant increase of TOS but decrease of TAS was found in the blood of untreated patients. The treatment resulted only in the normalization of TOS concentration. We have revealed a significant correlation between plasma GAGs and: MMP-3 (r=0.54), TOS (r=0.64) and urinary GAGs (r=0.55), respectively.
Proteoglycan/glycosaminoglycan alterations in JIA patients, which are stimulated by MMP-3 and reactive oxygen species (ROS), indicate rather systemic disturbance of extracellular matrix metabolism, and not merely local changes which occur in articular structures. Given the destructive potential of ROS and MMPs and their hyperexpression in JIA, inhibition of these compounds should bring a substantial clinical benefit.