@article{8e9d2062640a40d2984e813892c1e06a,
title = "Desquamative interstitial pneumonia and respiratory bronchiolitis- associated interstitial lung disease",
abstract = "Background: Desquamative interstitial pneumonia (DIP) and respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) are uncommon forms of interstitial lung disease and have been incompletely characterized. Study objectives: To further characterize the clinical features and course of subjects with DIP and RB-ILD. Design: Retrospective study. Setting: Tertiary care, referral medical center. Patients: Twenty-three subjects with DIP and 12 subjects with RB-ILD seen over a 12-year period between 1990 and 2001. Interventions: None. Results: The study population included 19 men (54%) and 16 women (46%). The mean (± SD) age at diagnosis was 46 ± 10 and 43 ± 7 years, respectively, for patients with DIP and RB-ILD. All subjects were either current or previous smokers except for three subjects with DIP. The diagnosis was confirmed in all cases by surgical lung biopsy. Bronchoscopy with transbronchial lung biopsy had been performed in 12 patients and was nondiagnostic in all. The most common pulmonary function abnormality was a reduced diffusing capacity of the lung for carbon monoxide. A CT scan of the chest revealed ground-glass opacities bilaterally in most patients who had DIP and RB-ILD. No differences were observed between subjects with DIP and RB-ILD with respect to clinical features, radiologic findings, or pulmonary function test results. The clinical course was characterized by relative stability in the majority of patients in both groups and a partial response to corticosteroid therapy. Five deaths were observed, including three resulting from progressive diffuse lung disease, all in subjects with DIP. Conclusions: We concluded that DIP and RB-ILD are chronic disease processes that in most patients are related to smoking. Persistent abnormalities can be seen on pulmonary function testing and radiologic studies despite smoking cessation and corticosteroid therapy. Corticosteroid therapy appeared to be associated with modest clinical benefit but usually not with resolution of disease. Progressive disease with eventual death can occur in subjects with DIP, especially with continued cigarette smoking.",
keywords = "Desquamative interstitial pneumonia, Interstitial lung disease, Respiratory bronchiolitis",
author = "Ryu, {Jay H.} and Myers, {Jeffrey L.} and Capizzi, {Stephen A.} and Douglas, {William W.} and Robert Vassallo and Decker, {Paul A.}",
note = "Funding Information: We conducted a computer-assisted search of the Mayo Clinic database to identify cases of DIP and RB-ILD that were seen at our institution over a 12-year period between January 1, 1990, and December 31, 2001. All lung biopsy specimens were reviewed to confirm the histopathologic pattern of either DIP or RB-ILD. RB-ILD was defined by the presence of clinical and radiologic evidence of ILD occurring in a patient with histologically proven respiratory bronchiolitis (RB) seen on a surgical lung biopsy specimen. The histologic diagnosis of RB required the presence of yellow-brown-pigmented macrophages in the lumens of respiratory bronchioles, alveolar ducts, and peribronchiolar alveolar spaces without significant associated interstitial pneumonia. Similarly, DIP was diagnosed in patients with clinical and radiologic evidence of ILD, and a histologic pattern of DIP on surgical lung biopsy specimens. Several investigators 4 5 9 10 have highlighted the histologic overlap between RB and DIP. For the purposes of our study, DIP was defined by the presence of pigmented macrophages diffusely involving alveolar spaces in at least one low-magnification field (×40) without a bronchiolocentric distribution and accompanied by diffuse alveolar septal thickening due to alveolar septal inflammation with or without fibrosis. Patients with incidental RB or DIP noted on their lung specimen obtained for an unrelated purpose ( eg , lung cancer resection) were excluded from this study. Medical records were examined in detail to gather clinical, radiologic, and pulmonary function data at presentation. Follow-up data regarding their clinical course, results of subsequent radiologic and pulmonary function studies, response to treatment, and clinical outcome also were extracted. The eventual clinical outcome was assessed at the time of the last available follow-up visit and was categorized as improved, stable, or worsened using the criteria published in a American Thoracic Society (ATS)/European Respiratory Society (ERS) statement. 11 These criteria include the assessment of changes in respiratory symptoms, radiologic findings, and pulmonary function measurements ( ie , total lung capacity, vital capacity, diffusing capacity of the lung for carbon monoxide [D lco ], and oxygen saturation or Pa o 2 ). 11 Spirometry and measurements of lung volumes and D lco were performed in our laboratory using standard techniques. 12 Pulmonary function data included plethysmographically determined total lung capacity, FVC, FEV 1 , FEV 1 /FVC ratio, and D lco . This study was approved by the Mayo Foundation institutional review board. Patients who did not authorize the use of their medical records for research were excluded from this study (two patients). ",
year = "2005",
doi = "10.1378/chest.127.1.178",
language = "English (US)",
volume = "127",
pages = "178--184",
journal = "Chest",
issn = "0012-3692",
publisher = "American College of Chest Physicians",
number = "1",
}