Original article Metastasin S100A4 is increased in proportion to radiographic damage in patients with RA

Objective. To assess the potential of metastasin S100A4 as a biological marker in patients with RA. Methods. A total of 87 unselected patients with established RA (disease duration 244 years) and treated with MTX and infliximab at a single rheumatology centre were included in a cross-sectional study. Radiographs of hands and feet were taken prior to infliximab treatment and at inclusion (time interval 48 ± 27 months) and scored for the radiographic damage. S100A4 levels were analysed in relation to radiographic damage, clinical disease activity (DAS-28), inflammation (IL-6, CRP, ESR), bone and cartilage markers [MMP-3, COMP, C-telopeptide of type I collagen (CTX-I)] and proto-oncogenes [survivin, insulin-like growth factor 1 (IGF-1), Flt3 ligand]. Results. High levels of S100A4 were associated with severe radiographic damage (OR = 3.40, P = 0.025), non-response to infliximab (OR = 4.63, P = 0.003), presence of antibodies to infliximab (OR = 6.24, P = 0.003) and high levels of Flt3 ligand (OR = 2.73, P = 0.04). Regression analysis showed that high S100A4 was predictive for radiographic progression during infliximab treatment [positive predictive value (PPV) 0.68, P = 0.05]. Low levels of S100A4 were associated with response to inflixima