TY - JOUR T1 - Elevation of serum napsin A in interstitial lung diseases in comparison with KL-6 and surfactant protein-D JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P732 AU - Takuya Samukawa AU - Tsutomu Hamada AU - Tomohiro Kumamoto AU - Masaki Watanabe AU - Keiko Mizuno AU - Ikkou Higashimoto AU - Hiromasa Inoue Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P732.abstract N2 - Napsin A is an aspartic proteinase with a molecular weight of approximately 38 kDa, which is expressed in normal lung parenchyma in type II pneumocytes, and we have shown that napsin A was founded high concentration in serum of patients with idiopathic pulmonary fibrosis (IPF). However, napsin A has not been tested as a marker for other forms of interstitial lung diseases (ILDs).The aim of this study was to investigate the potential of serum napsin A as a marker in various forms of ILD in comparison with KL-6 and surfactant protein-D (SP-D).Subjects consisted of 32 patients with chronic fibrosing interstitial pneumonia (CFIP) including 20 with IPF and 12 with nonspecific interstitial pneumonia (NSIP), 34 with ILD associated connective tissue disease (CTD-ILD), 11 with hypersensitivity pneumonia (HP), 5 with pulmonary alveolar proteinosis (PAP), 20 with bacterial pneumonia, and 20 healthy volunteers. Each serum levels of napsin A, KL-6, and SP-D were measured by commercially available ELISA kits.The serum napsin A levels were significantly (p<0.01) higher in patients with IPF (169.1 ± 97.1 ng/ml), NSIP (178.4 ± 221.5 ng/ml), CTD-ILD (109.0 ± 156.3 ng/ml), HP (333.1 ± 62.8 ng/ml), and PAP (500.1± 239.6 ng/ml) than those in bacterial pneumonia (38.6 ± 37.4 ng/ml) and healthy volunteers (28.9 ± 21.2 ng/ml). KL-6 and SP-D levels were also significantly higher in ILD patients than in bacterial pneumonia and healthy volunteers (p<0.01), and serum napsin A levels correlated with those of KL-6 and SP-D in patients with ILDs.Our findings shows serum napsin A may be useful biomarker for ILDs. ER -