Spontaneous increase of transforming growth factor beta production by bronchoalveolar mononuclear cells of patients with systemic autoimmune diseases affecting the lung.

The spontaneous increase in the transcription of the transforming growth factor beta (TGF beta) gene in bronchoalveolar mononuclear cells of patients with autoimmune diseases affecting the lung has been shown by northern blot assay and a nuclear run on transcription assay. Transcription of the TGF beta gene in bronchoalveolar mononuclear cells of patients with autoimmune diseases affecting the lung was increased 10 times compared with normal healthy subjects or patients with bronchial asthma as controls. This observation, confirmed by protein data, suggests that TGF beta, a potent mitogen for fibroblasts, may be produced in bronchoalveolar mononuclear cells during an active immune response in such patients and may be involved in autoimmune related changes of the pathophysiology of cytokine networks when the lung is affected, such as in lung fibrosis.