CRP and connective tissue disorder: TLC=total lung capacity; FVC=forced vital capacity; SARS-CoV-2=severe acute respiratory syndrome coronavirus 2; CAD=coronary artery disease; DM=diabetes mellitus; FEV1=forced expiratory volume in 1 second; CRP=c-reactive protein; DLCO=diffusion capacity of carbon monoxide; CTD=connective tissue disease; ILD=interstitial lung disease; IPAF=interstitial pneumonia with autoimmune features; WBC=white blood cell.