Lymphangiogenic factors are associated with the severity of hypersensitivity pneumonitis

BackgroundAntigen presenting cells play a pivotal role in the adaptive immune response in hypersensitivity pneumonitis (HP). It was hypothesised that lymphangiogenesis is involved in the pathophysiology of HP via cell transport.ObjectiveTo determine the clinical significance of lymphangiogenic factors in HP.MethodsLevels of vascular endothelial growth factors (VEGF)-A, VEGF-C, VEGF-D and CCL21 in the serum and bronchoalveolar lavage fluid (BALF) were measured in 29 healthy volunteers, 14 patients with idiopathic pulmonary fibrosis (IPF) and 26 patients with HP by ELISA. Additionally, immunohistochemical analyses were performed using lung specimens of patients with HP (n=8) and IPF (n=10).ResultsBALF VEGF-D levels were significantly elevated in patients with HP compared to the other groups. BALF VEGF–D levels in patients with HP correlated significantly with the BALF total cell and lymphocyte counts (r=0.485, p=0.014 and r=0.717, p