Heterogeneous Characteristics of Lymphatic Microvasculatures Associated with Pulmonary Sarcoid Granulomas

Rationale: Pulmonary sarcoidosis is a disorder characterized by noncaseating epithelioid granulomas that are anatomically distributed along lymphogenous routes. Currently, limited information is available about lymphangiogenesis in pulmonary sarcoidosis.Objective: To clarify the characteristics of lymphangiogenesis in pulmonary sarcoidosis.Methods: The concentrations of vascular endothelial growth factor (VEGF), VEGF-C, and VEGF-D in serum and bronchoalveolar lavage fluid from 65 patients with pulmonary sarcoidosis, 10 with idiopathic pulmonary fibrosis, and 29 healthy volunteers were measured by ELISA. Paraffin-embedded lung tissues obtained from 19 patients were used for immunohistochemical analyses, using primary antibodies against VEGF, VEGF-C, VEGF-D, podoplanin, VEGF receptor (VEGFR)-2, VEGFR-3, and CD73.Results: The serum and bronchoalveolar lavage fluid concentrations of VEGF and VEGF-C were significantly increased in patients with pulmonary sarcoidosis. Immunohistochemical analysis showed that VE...