CRP and rheumatoid arthritis: As expected, significant elevations of RF (median 16.1 versus 6.8 U/ml, p < 0.01), CRP (median 21.4 versus 2.6 U/ml, p < 0.01), and ACPA (median 1725 versus 15 U/ml, p < 0.01) were detected in patients with RA compared with HS (Table 2).