[Pneumopathy caused by hypersensitivity to isocyanates. Value and dangers of a realistic provocation test]

Organic isocyanates are responsible for bronchial pathology and in rare cases of hypersensitivity pneumonia. We present a new observation supported by a complete lung function assessment, histology of a transbronchial biopsy and a positive bronchial challenge test. The progress of the disorder was followed by repeated lung function measurements and bronchoalveolar lavage. The alveolar response at first showed an alveolar leukocytosis, then a mixed picture, finally becoming a pure lymphocytosis. The activity of the alveolar cells was assessed for T lymphocytes by cytofluorimetry, the presence of DRa like and LMR antigens and lastly for macrophages with Gallium scans. The inflammatory response was followed by analysing the proteins in the lavage liquid. The value of studying alveolar cell-activity and equally alveolar protein content is underlined in this study and reminds one of the character, sometimes unpredicted and dangerous, of challenge tests using isocyanates.