Bronchoalveolar Lavage in Occupational Lung Diseases Carlos Robalo Cordeiro, M.D., Ph.D., 1 Jessica Cemlyn Jones, M.D., 1 Tiago Alfaro, M.D., 1 and Anto ´ nio Jorge Ferreira, M.D., M.S.C. 2 ABSTRACT Occupational lung diseases (OLDs) are related to the exposure and inhalation of organic, inorganic, and synthetic particles, fumes, gases, or infectious agents. From the long list of OLDs this article focuses the discussion on bronchoalveolar lavage (BAL) in parenchymal immunoinflammatory conditions, such as hypersensitivity pneumonitis (HP) and pneumoconiosis. Several antigens may cause HP, including products of plant or animal origin, aerosolized microorganisms, and organic chemicals. BAL is used not only to assess the pathogenesis of these diseases but also to identify the typical pattern of intense lymphocytic alveolitis, usually with a CD4:CD8 ratio below normal and frequently with the presence of mast cells, plasma cells, and foamy macrophages. Pneumoconioses are chronic interstitial lung diseases caused by the inhalation of mineral and metallic inorganic particles/dusts in an occupational setting, showing a decreasing prevalence in recent years. BAL is a useful tool not only to express the complex pathogenic mechanisms of these entities but also in excluding other diagnoses and causes of alveolitis, and to document specific exposures, such as the identification of asbestos bodies (ABs) in asbestosis or the proliferative response of BAL lymphocytes to beryllium in chronic beryllium disease (CBD). KEYWORDS: Bronchoalveolar lavage, occupational lung diseases, hypersensitivity pneumonitis, pneumoconiosis The risks of injury and lung disease have been recognized in mining since the 16th century and were elegantly described at that time by Agrı ´cola. Currently we are aware that there is an ongoing increase of occupational lung diseases (OLDs) in several developed or developing countries, and that, in Western countries, there is a shift in these diseases from pneumo- coniosis to occupational asthma, the current most com- mon work-related respiratory event. 1 This is closely related to industrial development and the improvement of new biotechnologies, with changes not only in agriculture and basic industries, like mining and metallurgy, reflected in fewer risk populations, better hygiene measures, and less harmful exposure, but also in the widespread use of enzymes, leading to a higher degree of sensitized workers, ex- pressed in an increasing number of allergic occupational diseases. 2 1 Department of Pulmonology and Allergology, Coimbra University Hospital, Coimbra, Portugal; 2 Institute of Hygiene and Social Medi- cine, Coimbra Medical School, Coimbra, Portugal. Address for correspondence and reprint requests: Carlos Robalo Cordeiro, M.D., Ph.D., Department of Pulmonology and Allergology, Coimbra University Hospital, Praceta Mota Pinto, 3000 Coimbra, Portugal (e-mail: crobalo@mail.telepac.pt). Bronchoalveolar Lavage; Guest Editors, Robert P. Baughman, M.D., Ulrich Costabel, M.D., and Keith C. Meyer, M.D. Semin Respir Crit Care Med 2007;28:504–513. Copyright # 2007 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel: +1(212) 584-4662. DOI 10.1055/s-2007-991523. ISSN 1069-3424. 504