Serum matrix metalloproteinase activity relating to cartilage destruction in rheumatoid arthritis

Abstract Aims: The aim of this study was to determine which matrix metalloproteinases (MMPs) are involved with C‐reactive protein (CRP) and which stage of rheumatoid arthritis (RA) correlated with MMP‐9 or MMP‐13 level. Methods: In the present clinical trial, we analysed MMP‐9 activity and MMP‐13 activity in 53 RA patients. We examined the presence of MMP‐9 and MMP‐13 in the synovium tissue and articular cartilage in RA patients by immunohistochemistry. In addition, we compared these factors and clinical Steinbrocker staging. Results: We found that MMP‐9 in blood serum correlates significantly with CRP. MMP‐13 also correlates with CRP but the coefficiency with CRP is much higher in MMP‐9 (r = 0.6694) than in MMP‐13 (r = 0.4037). MMP‐9 and MMP‐13 did not correlated with rheumatoid factor (RF). MMP‐9 level is increased in stages II and III in RA. On the other hand, MMP‐13 is increased in stages III and IV. Our results indicated that early stage RA shows high MMP‐9 release in serum while late stage RA shows high MMP‐13 release. Conclusion: MMP‐9 activity may correlate with synovium proliferation with vascularization, and serum MMP‐13 activity may correlate with the grade of joint destruction in rheumatoid arthritis.