04 L (90.7% of predicted), 2.84 L (86.9%), 2.30 L (86.8%), and 81.0% respectively.

TLC, RV, and RV/TLC were 4.80 L (93.8%), 1.76 L (112 %), and 36.7% (100%) respectively. DLCO was 14.64 mL/min/mmHg (88.9%) and DLCO/VA was 3.73/min/mmHg (84%). Bronchoalveolar lavage (BAL) (recovery rate; 63/150) revealed high total cellularity (36 x 104 cells/ml) consisting of 22% lymphocytes, 2% neutrophils, and 2% eosinophils. BAL lymphocytosis was suggestive of BAY 73-4506 manufacturer NSIP and transbronchial biopsies of the right lung (rS9) showed lymphocyte infiltration with no evidence of infection. However, the specimens obtained were insufficient to allow for a definitive diagnosis. The patient then underwent thoracoscopic biopsy. The main finding of the surgical biopsy specimen (rS9) was irregular interstitial fibrosis with mild chronic inflammation, which ranged

from the peripheral to the central part of lobule (Fig. 1c). The patchy distribution of fibrotic changes seen in some subpleural regions was similar to UIP, while the fibrotic process was temporally homogeneous. The lung architecture was relatively preserved and honeycombing selleck chemicals was not observed. These pathological findings were consisted with that of fibrotic NSIP, and centrilobular emphysema in the non-fibrotic lesion and focal intraluminal accumulation of macrophages suggested superimposed smoking effects (Fig. 1d, e). Clinical, radiological, and pathological information established the diagnosis of idiopathic NSIP. Although we planned to treat the patient with prednisolone plus an immunosuppressive agent, he refused the medication due to an improvement in his cough following the complete cessation of smoking after the surgical biopsy. Moreover, ground-glass opacity and reticular patterns on HRCT were found to have gradually improved without medication during the next 4 months (Fig. 1f) and KL-6 was reduced to

392 U/ml. No evidence of exacerbation was detected during the 15-month follow-up. Possible pathogenic factors implicated in smoking with interstitial fibrosis may include oxidative stress [4], decreased HDAC2 activity [5], VEGF expression [6], and the up-regulation of TNF-α [7]. However, the impact of the cessation of smoking during the clinical course of NSIP remains to be established. PFKL To the best of our knowledge, this is the first reported case of fibrotic NSIP that markedly improved without medication after the complete cessation of smoking, which suggested that smoking may be an etiological factor in some patients with NSIP. The association of emphysema with NSIP, as shown in our case, and differences in the morphological features on HRCT between non-smokers and smokers may support this hypothesis [3]. Differential diagnosis of this case includes DIP, combined pulmonary fibrosis and emphysema (CPFE), and smoking-related interstitial fibrosis (SRIF). DIP usually responds to corticosteroid therapy. However, some cases progress to fibrosis, despite treatment [8].