MMP12 and rheumatoid arthritis: Quantification of the above indicated markers revealed that CD163+ macrophages from UA>RA and UA>PsA exhibited similar expression levels of activin A, TNFα and MMP12 as CD163+ macrophages from established RA and PsA, and higher levels than CD163+ macrophages from healthy synovium (Supplementary Figure 1, Figure 3B).