Current status of idiopathic nonspecific interstitial pneumonia.

Pulmonary pathologists were aware of cases of idiopathic interstitial pneumonia (IIP) that morphologically did not fit Liebow's classification scheme. These cases were labeled as "cellular interstitial pneumonia" or "chronic interstitial pneumonia not otherwise specified." The term nonspecific interstitial pneumonia (NSIP) was first used in relation to a pattern of lung interstitial inflammation seen in association with human immunodeficiency virus (HIV) infection. In 1994 NSIP was used to indicate a group of subacute or chronic interstitial pneumonias characterized morphologically by interstitial inflammation or fibrosis or both, with preservation of the lung architecture and the absence of typical findings for any of the other main categories of IIP (mainly usual interstitial pneumonia, desquamative interstitial pneumonia, and bronchiolitis obliterans organizing pneumonia). Although these patients presented with "nonspecific" lung histology (categorized as cellular and fibrotic variants), and with a broad spectrum of associated clinical conditions, such as connective tissue diseases (CTDs), environmental exposure, and previous acute lung injury, they showed some peculiar clinical aspects, including favorable response to corticosteroid treatment and overall good prognosis.The clinical and radiographic profiles were better defined in the last decade. The NSIP pattern is the histological background of a subacute/chronic interstitial pneumonitis that may be observed in many conditions, including CTD, drug-induced lung disease, hypersensitivity pneumonitis, slowly healing diffuse alveolar damage (DAD), relapsing organizing pneumonia, occupational exposure, immunodeficiency (mainly HIV infection), graft versus host disease (GVHD), familial pulmonary fibrosis, immunoglobulin G4 (IgG4)-related sclerosing disease, with or without overlap features with Rosai-Dorfman disease, multicentric Castleman disease, and myelodysplastic syndrome. Rarely, NSIP is the histology recognized in patients with idiopathic interstitial pneumonitis, in whom efforts to find potential causative exposures are futile. This entity occurs mostly in middle-aged, never-smoker women, with a likely association with an autoimmune background. High-resolution computed tomographic (HRCT) scans typically demonstrate ground-glass attenuation with a bibasilar distribution, or in the fibrotic variant, ground-glass attenuation along with reticular lines and traction bronchiectasis. The prognosis is good compared with idiopathic pulmonary fibrosis (IPF), and therapeutic options include mainly corticosteroids and immunosuppressive agents. Recently a more precise definition of clinical profiles and radiographic findings of idiopathic NSIP allows consideration of less invasive diagnostic procedures (bronchoalveolar lavage, transbronchial lung biopsy). Better understanding of pathogenetic mechanisms might widen the therapeutic horizon giving a role to new therapeutic options in more severe cases.

Poletti V ，Romagnoli M ，Piciucchi S ，Chilosi M ... -  《-》

Fibrotic idiopathic interstitial pneumonia: high-resolution computed tomography considerations.

Lynch DA 《SEMINARS IN RESPIRATORY AND CRITICAL CARE MEDICINE》

S100A9 in BALF is a candidate biomarker of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause, and the prognosis remains poor. On the other hand, other fibrotic interstitial pneumonias such as idiopathic nonspecific interstitial pneumonia (I-NSIP) and collagen vascular disease-associated interstitial pneumonia (CVD-IP) resemble IPF, but they respond to therapy and the prognosis is better. We searched for biomarkers to distinguish IPF from other fibrotic interstitial pneumonias and investigated whether S100A9 could be useful for discriminating types of fibrotic interstitial pneumonia based on our preliminary proteomic findings. We measured S100A9 levels in serum and bronchoalveolar lavage fluid (BALF) from 28 patients with IPF, 15 with I-NSIP, 20 with cryptogenic organizing pneumonia (COP), 35 with CVD-IP and 23 healthy individuals (controls) using enzyme-linked immunosorbent assays. S100A9 in the lung was also immunohistochemically localized. S100A9 levels in BALF, but not in serum, were significantly elevated in patients with IPF compared with I-NSIP, COP, CVD-IP and healthy individuals. S100A9 immunoreactivity was localized mainly in macrophages and neutrophils in lung specimens from patients with IPF. The results of receiver operating characteristic (ROC) curve analysis showed that BALF S100A9 levels had sufficient specificity and sensitivity to distinguish IPF from I-NSIP and CVD-IP. S100A9 in BALF might serve as a candidate biomarker to discriminate between IPF and other fibrotic interstitial pneumonias.

Hara A ，Sakamoto N ，Ishimatsu Y ，Kakugawa T ，Nakashima S ，Hara S ，Adachi M ，Fujita H ，Mukae H ，Kohno S ... -  《-》

Review series: Aspects of interstitial lung disease: connective tissue disease-associated interstitial lung disease: how does it differ from IPF? How should the clinical approach differ?

de Lauretis A ，Veeraraghavan S ，Renzoni E 《-》

[Histopathological classification of idiopathic interstitial pneumonias].

Povýsil C 《-》