title: Lymphangiogenic factors are associated with the severity of hypersensitivity pneumonitis.
abstract: BACKGROUND
  Antigen 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.
  
  
  OBJECTIVE
  To determine the clinical significance of lymphangiogenic factors in HP.
  
  
  METHODS
  Levels 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).
  
  
  RESULTS
  BALF 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<0.0001, respectively). BALF VEGF-C and CCL21 levels were increased in patients with HP compared to healthy volunteers, but not patients with IPF. BALF CCL21 levels were negatively correlated with the forced expiratory volume in 1 s percentage and diffuse capacity of the lung for carbon monoxide (r=-0.662, p=0.007 and r=-0.671, p=0.024, respectively). According to the immunohistochemical analyses, CCL21 was expressed in the lymphatic endothelium in both conditions and CCR7(+) cells were aggregated around lymphatics in patients with HP, but not in patients with IPF.
  
  
  CONCLUSIONS
  Lymphangiogenic factors might be associated with the inflammatory and functional severity of HP. The increased BALF VEGF-D levels were associated with lymphatic alveolitis intensity, and CCL21 with lung function impairment.
authors.affiliation: Department of Pulmonary Medicine, Allergy and Rheumatology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Department of Pulmonary Medicine, Allergy and Rheumatology , Iwate Medical University School of Medicine , Morioka , Japan ; Department of Respiratory Medicine , Iwate Prefectural Chubu Hospital , Kitakami , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Mouri
authors.affiliation: Department of Pulmonary Medicine, Allergy and Rheumatology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Niisato
authors.affiliation: Department of Pulmonary Medicine, Allergy and Rheumatology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Nitanai
authors.affiliation: Department of Pulmonary Medicine, Allergy and Rheumatology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Department of Pharmacology , Ehime University Graduate School of Medicine , Toon , Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Ogasawara
authors.affiliation: Department of Gastroenterology and Hepatology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Ryujin
authors.initials: R
authors.lastname: Endo
authors.affiliation: Department of Pulmonary Medicine , Morioka Tsunagi Onsen Hospital , Morioka , Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Konishi
authors.affiliation: Department of Pathology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sugai
authors.affiliation: Department of Pathology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sawai
authors.affiliation: Department of Pulmonary Medicine, Allergy and Rheumatology , Iwate Medical University School of Medicine , Morioka , Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Yamauchi
keywords: Allergic Alveolitis