[Idiopathic fibrogenous interstitial pneumopathy].
Based on personal clinical observations in over one hundred cases and the data in the literature, a brief general review of the clinical and biological characteristics of chronic idiopathic fibrogenous interstitial pneumopathy (diffuse idiopathic interstitial fibrosis) is presented. Chief emphasis is placed on functional characteristics (inadequacy of the ventilation/perfusion ratio and disease of the small airways and of the interstitium per se), morphologic considerations, and analysis of bronchoalveolar lavage fluid. Typically the disease runs its course within about 4 years following diagnosis, the evolution being marked by episodes of infection complicating the concurrent respiratory insufficiency. Complications stemming from pre-existing coronary insufficiency or neoplastic transformation can occur in elderly patients. Recent advances have been the result of experimental data, of a better understanding of the biochemical structure of the lung (particularly with respect to the metabolism of collagen) and of cytologic and isotopic investigations, especially iterative bronchoalveolar lavage and gallium scintigraphy. Treatment remains disappointing, however, and principally symptomatic (corticotherapy and azathioprine). In relation to acquired fibrosis (common pneumoconiosis, extrinsic allergic alveolitis, iatrogenic pneumopathy, pulmonary fibrosis secondary to systemic disease) this syndrome represents a distinct, if not unequivocal or specific entity.