CRP and idiopathic interstitial pneumonia: During the chronic progression of interstitial pneumonia, it has been reported that a baseline CRP level associated with scleroderma was a long-term prognostic factor [21], and that pirfenidone administration for IPF reduced the levels of inflammatory markers including CRP [22], suggesting that there may be a relationship between the progression of interstitial pneumonia and serum CRP level.