TY - JOUR T1 - Neutrophil gelatinase-associated lipocalin in idiopathic pulmonary fibrosis JF - European Respiratory Journal JO - Eur Respir J SP - 1807 LP - 1809 DO - 10.1183/09031936.00192613 VL - 43 IS - 6 AU - Kohei Ikezoe AU - Tomohiro Handa AU - Kiyoshi Mori AU - Kizuku Watanabe AU - Kiminobu Tanizawa AU - Kensaku Aihara AU - Tatsuaki Tsuruyama AU - Aya Miyagawa-Hayashino AU - Akihiko Sokai AU - Takeshi Kubo AU - Shigeo Muro AU - Sonoko Nagai AU - Toyohiro Hirai AU - Kazuo Chin AU - Michiaki Mishima Y1 - 2014/06/01 UR - http://erj.ersjournals.com/content/43/6/1807.abstract N2 - To the Editor:Neutrophil gelatinase-associated lipocalin (NGAL) is a 25 kD lipocalin that is covalently bound to matrix metalloproteinase (MMP)-9 produced by neutrophils [1]. NGAL in blood or bronchoalveolar lavage fluid (BALF) may reflect neutrophilic inflammation in the lungs [2, 3], and it is highly induced in injured epithelial cells, including those in the lung [4]. Possible roles for neutrophilic inflammation and epithelial injury have been reported in idiopathic pulmonary fibrosis (IPF). Thus, we hypothesised that NGAL may be associated with the pathogenesis of IPF. To investigate the roles of NGAL in IPF, we used immunohistochemical staining for lung specimens and measured plasma and BALF NGAL levels. Our study was approved by the Ethics Committee of Kyoto University (approval No. E438), and written informed consent was obtained from all study participants.First, we immunohistochemically stained the lung tissue specimens of six IPF patients, two nonspecific interstitial pneumonia (NSIP) patients, and a control (normal area distant from the lesion of surgically diagnosed organising pneumonia) for NGAL using a conventional method [5]. We also performed sequential immunofluorescent staining for NGAL and MMP-9. Immunohistochemical staining showed that NGAL was abundantly expressed in airway epithelial cells that covered the honeycomb cysts in IPF (fig. 1a and b). Further, histologically normal bronchioles in the fibrotic lesions also exhibited abundant NGAL expression, although apparently normal alveolar walls exhibited little NGAL expression. NGAL was also expressed in macrophages, neutrophils and some alveolar epithelial cells.Figure 1– Immunohistochemical staining results for neutrophil gelatinase-associated lipocalin (NGAL) in lung specimens from: a and b) idiopathic pulmonary fibrosis (IPF) … ER -