CALCA and rheumatoid arthritis: The median PCT were significantly higher in RA patients (0.23; interquartile range (IQR) 0.00–10.56 × 10−3 ng/mL) compared with the controls (0.00; IQR 0.00–0.00 × 10−3 ng/mL), p < 0.001 (Figure 1).