Keith C. Meyer, MD

abstract: Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease of unknown etiology that leads to progressive fibrosis and respiratory failure. Patients with IPF typically present in their sixth to seventh decade of life with the insidious onset of progressive dyspnea and cough. Lung histopathology reveals the distinct lesion of usual interstitial pneumonia (UIP), and other causes of UIP, such as collagen-vascular disease, drug exposure, or occupational exposures, must be excluded. A confident clinical diagnosis of IPF can often be made without resorting to surgical lung biopsy if certain clinical features are present and a typical pattern is identified on high-resolution CT (HRCT) scanning of the thorax. Changes on HRCT scans that are typical for UIP include a predilection for peripheral and basilar lung zones with patchy involvement and sparing of more central areas, especially in upper lung zones. (J Respir Dis. 2007;28(7):283-292)

Abstract: Important components of the workup for interstitial lung disease (ILD) include the history and physical examination, chest radiography, high-resolution CT (HRCT), pulmonary function testing and, in some cases, bronchoalveolar lavage (BAL) and/or biopsy. Pulmonary function tests usually show a restrictive ventilatory impairment. However, some patients have a mixed restrictive/obstructive pattern; in fact, almost 50% of patients with sarcoidosis have airflow obstruction at presentation. HRCT has an increasingly important role in the assessment of ILD. In some cases, the results may obviate the need for biopsy. BAL can help confirm the diagnosis of ILD; it also can identify conditions such as infection or hemorrhage or suggest an alternative diagnosis. Surgical lung biopsy has the advantage of yielding samples of lung tissue that are usually diagnostic, especially if HRCT is used to target lung regions. (J Respir Dis. 2005;26(11):466-478)

Abstract: Many patients with sarcoidosis are asymptomatic at presentation and have bilateral hilar adenopathy on a chest radiograph obtained for other reasons. Symptomatic patients usually present with chronic cough, dyspnea, or noncardiac chest pain. Extrapulmonary organ involvement is not uncommon. Lung biopsy shows well-formed noncaseating granulomas in a bronchovascular distribution. Interstitial lung disease also may result from collagen vascular disease, such as systemic lupus erythematosus and Sjögren syndrome. In patients with acute hypersensitivity pneumonitis, cough, dyspnea, and flu-like symptoms occur within 12 hours of exposure to the inciting antigen, such as pigeon stool or moldy hay. Some patients have a subacute or chronic course, probably as a result of continued exposure to the offending antigen. In acute hypersensitivity pneumonitis, the chest radiograph may show diffuse small nodules, whereas in chronic disease, reticular lines or fibrosis may be seen. (J Respir Dis. 2005;26(10):443-448)

Abstract: The idiopathic interstitial pneumonias (IIPs) are the most commonly diagnosed forms of interstitial lung disease. These diseases represent specific clinicopathologic entities characterized by varying degrees of lung parenchymal inflammation and fibrosis. While most patients present with chronic dyspnea and have evidence of restriction on pulmonary function testing, certain findings can help differentiate among the IIPs. For example, patients with idiopathic pulmonary fibrosis (IPF)--the most common IIP--commonly present in the sixth or seventh decade of life, while those with desquamative interstitial pneumonia or respiratory bronchiolitis with interstitial lung disease typically present in the third or fourth decade of life and have a history of smoking. IPF is characterized by usual interstitial pneumonia (UIP) on lung biopsy; a UIP pattern can also be identified by high-resolution CT. (J Respir Dis. 2005;26(9):372-378)