Characterization of myofibroblasts cultured from small volumes of diagnostic bronchoalveolar lavage fluid samples

Myofibroblasts are supposed to have a key role in pathogenesis of fibrotic lung diseases. Our aim was to standardize process for culturing cells from small volumes of diagnostic bronchoalveolar lavage (BAL) fluid samples and to characterize the cultured cells. Small volumes of BAL samples were collected from 98 patients that underwent bronchoscopy and BAL for diagnostic purposes. Cells were visualized by electron and immunoelectron microscopy. Proliferation and invasion capacities as well as stem cell properties of the cells were evaluated. Colonies of proliferating fibroblast type cells could be seen in 62% of samples. The success rate varied significantly based on the disease being 92% in idiopathic pulmonary fibrosis (IPF), 80% in non-specific interstitial pneumonia, 89% in collagen vascular disease associated interstitial lung disease, 62% in asbestosis, 53% in sarcoidosis, 100% in allergic alveolitis, 80% in drug reaction, 40% in lung cancer and 25% in normal lung. The success was not dependent on volume or cell amount of the BAL sample. The cultured cells were either fibroblasts or myofibroblasts. Typical features of myofibroblasts were detectable in the cells by electron and immunoelectron microscopy. Some cell samples exhibited differentiation potency into osteoblasts or adipocytes. The invasion capacity varied in different disorders being the highest in IPF-patients. We concluded that myofibroblasts can be cultured from small volumes of diagnostic BAL fluid samples. This method could increase the usability of BAL fluid both in diagnostics of interstitial lung diseases and in scientific research.