CALCA and rheumatoid arthritis: The first important finding from our data was that the serum PCT significantly increased (p < 0.0001) in early RA patients (0.065 ng/ml) compared with healthy controls (0.024 ng/ml) and the serum CT concentrations were significantly lower (p < 0.0001) in patients with early RA (0.880 pg/ml) compared with healthy controls (3.159 pg/ml).