Indeed, RA patients with low SJC28 but high PtGA had significantly higher anti-PTX3 antibodies than those with both low SJC28 and low PtGA, but their levels were not dissimilar to levels found in patients with high SJC28 (all with high PtGA), revealing that such a group of patients with high levels of self-reported pain despite small evidence of inflammation represent true disease activity and not just secondary painful syndromes. Here, PTX3 is linked to Down syndrome.