MMP3 and rheumatoid arthritis: In conclusion, the most significant and original findings of the current study are (i) elevated levels of circulating MMP-3, which may identify a subset of RA patients likely to develop severe disease, are significantly associated with SDAI, proinflammatory cytokines, and most strongly with CRP and SAA; (ii) CRP and SAA are more strongly correlated with disease activity in early RA than MMP-3; (iii) measurement of either CRP or SAA in combination with MMP-3 on presentation may be useful in the assessment of disease activity and prediction of progression in early RA.