CRP and idiopathic pulmonary fibrosis: The risk of a BAL-AE in patients with IPF has been estimated to be 1.99%–2.4% (Hiwatari et al., 1994; Sakamoto et al., 2012), and a lower forced vital capacity (FVC) and carbon monoxide diffusing capacity (DLCO), increased C-reactive protein (CRP) level, and high body temperature have been suggested as risk factors (Sakamoto et al., 2012).