Granulocyte–Macrophage Colony-Stimulating Factor Inhalation Therapy for Severe Pulmonary Alveolar Proteinosis

Background: Some patients with pulmonary alveolar proteinosis (PAP) still present with high recurrence rate after large-volume whole lung lavage (WLL). Granulocyte–macrophage colony-stimulating factor (GM-CSF) has been proved to be effective for PAP, but clinical research on GM-CSF inhalation therapy combined with WLL for severe PAP is rare in Asia. Study Question: This study aimed to investigate the clinical efficacy of GM-CSF inhalation combined with WLL in Chinese patients with PAP. Study Design: We performed regression analysis on 33 patients with severe PAP who underwent WLL alone or WLL combined with GM-CSF inhalation. The patients were put into 2 groups, WLL group and GM-CSF/WLL group. Measures and Outcomes: Physiologic, serologic, and radiologic features of the 2 groups at different time points after treatment and the recurrence rates at 1-year follow-up were compared. Results: There were no significant differences in lung function, blood gas analysis indices, and lung CT between the 2 groups after 1-week treatment (P > 0.05). After 3-month treatment, the GM-CSF/WLL group showed significantly faster improvement in FEV1%Pred (P = 0.028), FVC%Pred (P = 0.014), PaO2 (P = 0.022), PA-aO2 (P = 0.009), PaO2/FiO2 (P = 0.025), 6-minute walking test (P = 0.002), and lung CT parameters (P < 0.05) compared with the WLL group. The recurrence rate at the 1-year follow-up in the GM-CSF/WLL group (5.5%) was significantly higher than that in the WLL group (46.67%; P < 0.05). Conclusions: GM-CSF inhalation therapy combined with WLL is an effective treatment for patients with severe PAP, with further improvement in lung function at the base of WILL as well as reduction on re-WLL incidence.