Changes in bronchoalveolar lavage indices associated with radiographic classification in coal miners.
Previous studies on symptomatic coal miners have shown that alveolar macrophages, recovered by bronchoalveolar lavage (BAL), release excessive amounts of reactive oxygen species (ROS) and inflammatory cytokines. It has been proposed that these secretions may mediate cell injury and initiate the disease process. We hypothesized that acellular bronchoalveolar lavage fluid (BALF) indices in coal miners chronically exposed to coal dust may reflect the status of important homeostatic modulations in the lung that lead to the development of coal workers' pneumoconiosis (CWP). To test this hypothesis, we measured inflammatory status, oxidant burden, antioxidant defenses, cytokines, growth factors, fibronectin, and alpha(1)-antitrypsin (alpha(1)-AT) in the BALF of healthy never-smoker control subjects, never-smoker underground coal miners with negative radiographs (ILO 0/0-1/0), and two miners with moderate changes in the chest radiographs (ILO 2/2). Interestingly, indices of injury and inflammation increased with the progression of disease in coal miners. Antioxidant enzymes, such as catalase, glutathione peroxidase, and superoxide dismutase, showed a 19-fold, 22-fold, and 6-fold increase above control, respectively, in coal miners with category 2/2 CWP. Significant increases in the secretion of IL-1, IL-6, TNF-alpha, TGF-beta, fibronectin, and alpha(1)-AT also were evident in coal miners with disease. This up-regulation of antioxidant defenses and cytokines was not evident in coal miners in the absence of clinically evident radiographic disease. In addition, the concentration of lipid peroxidation by products in the BALF of coal miners without evidence of radiographic disease showed a moderate 3-fold increase, whereas, in coal miners with category 2/2 CWP it showed a 59-fold increase compared to control subjects. These results are in good agreement with our hypothesis that development of CWP and its progression may be correlated with an oxidative stress and up-regulation of cytokines and mediators of growth.
Vallyathan
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Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, and Section of Pulmonary and Critical Care Medicine, West Virginia University, Morgantown, West Virginia, USA. VAV1@CDC.GOC
Goins
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Lapp
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Pack
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Leonard
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Shi
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Castranova
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D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000502:physiology; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D011009:Pneumoconiosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011859:Radiography; D017382:Reactive Oxygen Species / Q000378:metabolism*
D016207:Cytokines; D018836:Inflammation Mediators; D017382:Reactive Oxygen Species