Abstract
Differential cell counts and fibronectin levels were recorded in bronchoalveolar lavage fluids (BALF) from patients with lung cancer, idiopathic pulmonary fibrosis (IPF), sarcoidosis, pneumonia, acquired immunodeficiency syndrome (AIDS), and chronic obstructive lung disease (COLD). In all groups fibronectin levels were significantly higher than in the control group; patients with sarcoidosis had a six-fold higher fibronectin level (mean values), AIDS 5.4-fold, pneumonia 4.4-fold, lung cancer, IPF and COLD 2.4-3.0-fold. In control smokers the fibronectin level was significantly higher compared to healthy nonsmokers (p<0.002). The increased fibronectin levels could not be explained by contamination of BALF with blood or leakage of plasma proteins. Thus, increased fibronectin levels probably reflect local (e.g. macrophage/fibroblast) synthesis.