[Bronchial hyperreactivity in miners with pneumoconiosis].

Hyperreactivity of a pneumoconiotic origin may manifest itself either at the level of the lung parenchyma or at the bronchial site. It may induce either clinical patterns, such as those which occur in the bronchospastic disease in coal-miners, or be the cause of functional disturbances in particular positive responses to aspecific challenge tests with acetylcholine; finally it may produce some radiologic or endoscopic changes in the lungs. The precise role of the causal agent of pneumoconiosis is difficult to assess by comparison with the role of bronchitis, more precisely that of the small airway disease, or the action of the numerous air pollutants or eventually the intervention of an individual predisposition. Bronchial hyperreactivity in pneumoconiotics may not be assimilated to a purely immunological phenomenon. The various changes induced in the lungs by the pneumoconiosis, above all at the level of the bronchi, contribute to a multifactorial etiology of this hyperreactivity. A better understanding of the phenomenon might result from further biological investigation of the respiratory tract.