CALCA and idiopathic pulmonary fibrosis: Mean (standard deviation (SD)) serum PCT was 3.58 ± 7.08 and 0.28 ± 0.52 ng/ml in patients with LC-IPF and IPF only, respectively, while median serum PCT (IQR) was 0.655± 3.60 and 0.07 ± 0.11ng/ml, in the two groups, p=0.016, respectively.