CRP and rheumatoid arthritis: As RF and ACPA autoantibodies have been associated to disease activity and inflammation in RA patients (Aletaha et al., 2015; de Brito Rocha et al., 2019), we divided FDR individuals and cRA patients from the SCREEN-RA/SCQM cohort as well as new-onset RA patient from the Rheuma-VOR cohort based on their RF and ACPA seropositivity and investigated potential differences in serum calprotectin and CRP levels.