PURPOSE: To investigate the clinical significance of surfactant protein-D (SP-D) and KL-6 in bronchoalveolar lavage fluid (BALF) and blood in patients with idiopathic pulmonary alveolar proteinosis (iPAP).
METHODS: We measured SP-D and KL-6 in both BALF and blood in 15 iPAP patients and 48 patients with interstitial lung diseases (ILD, diseased controls), including 20 with interstitial pneumonitis associated with collagen vascular diseases, 13 with idiopathic pulmonary fibrosis and 15 with sarcoidosis, and 20 subjects without pulmonary diseases (lung controls) and investigate the clinical significance in iPAP.
RESULTS: Patients with iPAP had significantly higher BALF levels of SP-D and KL-6 than did lung and diseased controls. Blood SP-D and KL-6 were significantly higher in iPAP patients than in lung controls, and blood KL-6 was significantly higher in iPAP patients than in those with various ILD. BALF and blood KL-6 were highly correlated with serum lactate dehydrogenase, arterial oxygen tension and alveolar-arterial oxygen tension difference, the severity markers for iPAP and were significantly higher in iPAP patients required subsequent therapeutic lung lavage.
CONCLUSION: Elevated BALF and blood SP-D and KL-6 were found in iPAP patients. BALF and blood levels of KL-6 may be valuable in reflecting disease severity in patients with iPAP and predicting the need for subsequent therapeutic lavage.
CLINICAL IMPLICATIONS: KL-6 may be a useful marker for disease severity of iPAP and the need of therapeutic lung lavage.
DISCLOSURE: Fang-Chi Lin, No Financial Disclosure Information; No Product/Research Disclosure Information