Although CRP levels were higher in RA patients compared to PsA and AS patients, most patients presented with stable, low grade disease activity, as observed by DAS28 (2.5 ± 0.75) for RA, DAPSA (3.7 ± 2.7) for PsA patients and BASDAI scores (1.5 ± 1.6). This evidence concerns the gene CRP and rheumatoid arthritis.