Comparison of the serum and bronchoalveolar lavage fluid (BALF) levels of CCL21 among healthy volunteers and patients with idiopathic pulmonary fibrosis (IPF) and hypersensitivity pneumonia (HP). Comparison of the serum and bronchoalveolar lavage fluid (BALF) levels of CCL21 among healthy volunteers and patients with idiopathic pulmonary fibrosis (IPF) and hypersensitivity pneumonia (HP). (A) The serum CCL21 levels showed no difference among the three groups. (B) The BALF CCL21 levels were significantly elevated in patients with IPF and HP compared to healthy volunteers, although no difference was observed between patients with HP and patients with IPF. ***p<0.001. Masahiro Yamashita et al. BMJ Open Resp Res 2015;2:e000085 ©2015 by British Thoracic Society