Objective: To investigate the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF), GM-CSF/IL-3/IL-5 receptor common beta chain (GM-CSFbetacR), surfactant protein (SP)-A and SP-D in adult patients with idiopathic pulmonary alveolar proteinosis (PAP), so as to demonstrate the possible association of GM-CSF, GM-CSFbetacR, SP-A and SP-D with human PAP.
Methods: The protein expression of GM-CSF, GM-CSFbetacR, SP-A and SP-D in the alveolar macrophages and alveolar type II epithelial cells was detected by immunohistochemical staining.
Results: The age was 51.8 +/- 9.5 years old for patients with idiopathic PAP (6; males 4, females 2) and 48.8 +/- 12.6 years old for the control adult individuals (6; males 4, females 2). There was no difference in the expression of GM-CSF (P = 0.818) and SP-D (P = 0.24) in alveolar macrophages between patients with idiopathic PAP and the controls. The expression of GM-CSFbetacR (P = 0.002) and SP-A (P = 0.004) in alveolar macrophages of patients with idiopathic PAP was less than that in the controls. There was no expression of GM-CSF in alveolar type II epithelial cells of patients with idiopathic PAP and the controls. There was a little expression of GM-CSFbetacR in alveolar type II epithelial cells of the controls. There was no expression of GM-CSFbetacR in alveolar type II epithelial cells of patients with idiopathic PAP. There was no difference in the expression of SP-A (P = 0.818) and SP-D (P = 0.485) in alveolar type II epithelial cells between patients with idiopathic PAP and the controls.
Conclusion: The decreased protein expression of GM-CSFbetacR in alveolar macrophages may be one of the mechanisms causing dysfunction of the macrophages in adult patients with idiopathic PAP.