[Lymphomatoid granulomatosis and hypersensitivity pneumopathy. Clinical and biological study (serum and alveolar) toward a new pathogenic hypothesis of the disease].

The authors discussed the malign form of lymphomatoid granulomatosis on the basis of two cases and consider the possible role of an aerocontaminant which is usually responsible for the extrinsic allergic type of alveolitis. A detailed biochemical and cytological study of the alveolar fluid from one of these patients is presented in parallel with immunofluorescent histology and electron microscopy of the lung. The observed biochemical abnormalities in the alveolar fluid could be superimposed on those formed in certain types of hypertensive lung disease. On the other hand the cytology was different, the cytofluorimetric technique revealed a mononuclear cell population rich in RNA whose role in the genesis of the disease of malign nature are discussed. The hypothesis of a hypersecretion of IgA by this malign process is raised by immunofluorescent studies of the lung. The role of IgA in lymphomatoid granulomatosis and bird fanciers lung is discussed in the light of recent work on pigeon IgA.