Role of cytokines and mineral particle profile in the development of coal workers' pneumoconiosis as sssessed by bronchoalveolar lavage.
Weber-SL; Lapp-NL; Vallyathan-V; Castranova-V; Shumaker-J; Schwegler-Berry-D
Appl Occup Environ Hyg 1996 Jul; 11(7):923-927
Three cytokines, fibronectin, tumor necrosis factor alpha (TNF- alpha), and interleukin 1beta (IL-1beta), were measured in the bronchoalveolar lavage fluid (BAL) of coal miners asymptomatic for silicosis or coal workers' pneumoconiosis (CWP) in order to clarify the role of alveolar macrophages (AM) in the pathogenesis of silicosis and CWP. Twenty coal miners with at least 5 years of underground experience and 19 control subjects participated in this study; all subjects were nonsmokers. Each subject completed a questionnaire regarding occupational and medical history. Subjects underwent chest radiographs, were given a cardiopulmonary system physical examination, and were screened via spirometry and diffusing capacity to assess pulmonary function. Bronchoscopy with bronchoalveolar lavage in a subsegment of the right middle lobe was performed to remove AM; lavage fluid was extracted and cytokine analysis via immunoassay and spectrophotometry was performed. AM were pelleted and fixed, then subjected to particle analysis via scanning electron microscopy, and the results obtained from controls and miners were compared using Mann-Whitney-U statistics for nonparametric data analysis. TNF-alpha levels were lower in the BAL of miners than in controls, and AM from miners were observed to have significantly higher levels of intracellular particles. Neither IL-1beta or fibronectin was observed to be significantly different in the BAL of controls and miners. The authors conclude that the lack of disease in the presence of low level exposure may be the reason why coal miners asymptomatic for CWP show lower TNF- alpha and a lack of fibronectin and IL-1beta elevation in this study.
NIOSH-Author; Underground-miners; Mine-workers; Occupational-exposure; Lung-function; Pulmonary-function; Silica-dusts; Alveolar-cells; Immune-reaction; Coal-workers-pneumoconiosis; Statistical-analysis; Questionnaires; Humans
Applied Occupational and Environmental Hygiene