Although these diseases have a relatively good prognosis following smoking cessation, typically in Y-27632 combination with corticosteroid therapy, the causative role of smoking in fibrotic lung diseases remains controversial. Nonspecific interstitial pneumonia (NSIP) is characterized by the temporally homogeneous involvement of alveolar septa by inflammation and fibrosis, in contrast to the heterogeneity of usual interstitial

pneumonia (UIP). Most patients with interstitial pneumonia showing a pathological NSIP pattern are of unknown etiology, and the clinical features of fibrotic NSIP resemble idiopathic pulmonary fibrosis (IPF)/UIP. Although the prognosis of fibrotic NSIP was documented to be better than that of IPF/UIP [2], the relationship between smoking and NSIP has not yet been fully elucidated. In this report, we present a case of fibrotic NSIP with mild emphysema in an elderly male, whose symptoms, serum KL-6 level, and high-resolution computed tomography (HRCT) findings markedly improved without medication after smoking cessation. A 66-year-old man who enjoyed karaoke visited our department because of respiratory difficulties during singing. He smoked a pack of cigarettes a day for 45 years. He had a history of essential hypertension and hyperlipidemia, but not pulmonary or autoimmune diseases or occupational exposure to fibrogenic substances. Chest CT revealed

mild emphysema and faint interstitial changes in the lungs. OSI-906 cost Since neither obstructive 4-Aminobutyrate aminotransferase nor restrictive impairments were detected on pulmonary function tests, we recommended that the patient quit smoking without medication. However, he was unable to quit, and the appearance of a dry cough, increment in serum KL-6, and gradual worsening of interstitial changes on CT were observed during the next one and a half years without a decline in pulmonary function. Therefore, the patient was admitted for further examinations including bronchoscopy.

Physical examination indicated fine inspiratory crackles in both lungs. Laboratory values were as follows: white blood cell count, 8420/μl with normal differentiation; hemoglobin, 16.4 g/dl; platelet count, 21.4 x 104/μl; C-reactive protein, 0.25 mg/dl; serum KL-6, 930 U/ml (<500); anti-nuclear antibody, positive at 1:40 dilution based on the Japanese criteria with a homogenous and speckled pattern. No elevations were observed in specific autoantibodies (anti-DNA, anti-RNP, anti-SS-A, anti-SS-B, and anti-Scl-70 antibodies) for the corresponding connective tissue diseases. Chest X-ray showed no obvious abnormal findings; however, HRCT demonstrated mild emphysema in the upper lung fields (Fig. 1a). HRCT also revealed ground-glass opacity and reticular patterns without honeycombing in the lower lung fields, which were consistent with a NSIP pattern. A crazy-paving pattern, which was previously reported to be frequent in non-smokers with NSIP [3], was not observed (Fig. 1b).