To evaluate the clinical relevance of anti-GM-CSF antibodies in idiopathic pulmonary proteinosis.
Twelve idiopathic pulmonary alveolar proteinosis patients were examined on 19 occasions. To serve as controls, 2 patients with secondary pulmonary alveolar proteinosis, 54 patients with other pulmonary disorders, and 11 subjects without lung lesions were studied.
Anti-GM-CSF antibodies were detected using immunoblotting analysis and the titers determined semiquantitatively by serial dilution. Clinical parameters used to indicate severity of idiopathic pulmonary alveolar proteinosis were measured. Anti-GM-CSF antibodies were detected in 18 of 19 (95%) blood and 12 of 19 (63%) bronchoalveolar lavage fluid samples in 12 idiopathic pulmonary alveolar proteinosis patients on 19 occasions, but were absent in blood and bronchoalveolar lavage fluid samples obtained from all other studied subjects. Blood levels of anti-GM-CSF antibodies showed no significant correlation with the clinical variables indicative of severity of idiopathic pulmonary alveolar proteinosis. In contrast, the levels of bronchoalveolar lavage fluid anti-GM-CSF antibodies correlated significantly with those of serum lactate dehydrogenase, arterial oxygen tension, alveolar-arterial PO2 difference, ventilatory parameters, and all lung lesion scores measured on chest radiographs and thoracic computed tomography scans.
Our results confirmed that the presence of anti-GM-CSF antibodies in blood or bronchoalveolar lavage could serve as a diagnostic marker for idiopathic pulmonary alveolar proteinosis. Additionally, bronchoalveolar lavage fluid levels of anti-GM-CSF antibodies correlated well with the severity of idiopathic pulmonary alveolar proteinosis.
The titers of anti-GM-CSF antibodies in bronchoalveolar lavage fluid may reflect the severity of idiopathic pulmonary alveolar proteinosis.
Fang Chi Lin, None.