EXPRESSION OF TUMOR-NECROSIS-FACTOR-ALPHA IN CRYPTOGENIC FIBROSING ALVEOLITIS

We have studied 1 5 cases of cryptogenic fibrosing alveolitis stained with a monoclonal antibody reactive with human tumour necrosis factor- alpha (TNFalpha), a cytokine that has been implicated in inflammation and fibrosis. Seven were examples of lone cryptogenic fibrosing alveol itis and eight were examples of cryptogenic fibrosing alveolitis in pa tients with systemic sclerosis. There was widespread staining of epith elial cells, particularly hyperplastic type II pneumocytes. Macrophage s stained only weakly. In a control group of 10 patients dying of unre lated conditions, staining for TNFalpha was weak and, in the alveolar epithelium, was confined to a very occasional type II pneumocyte. The strong expression of TNFalpha in hyperplastic type II pneumocytes sugg ests that TNFalpha produced during alveolar epithelial regeneration ma y play a part in the fibrosis seen in this disease.