Clinical significance of levels of lung surfactant protein a in serum, in various lung diseases
Abe, S.; Honda, Y.; Ando, M.; Saita, N.; Kida, K.; Jinno, S.; Kondo, A.; Kuroki, Y.; Akino, T.
Nihon Kyobu Shikkan Gakkai Zasshi 33(11): 1219-1225
1995
ISSN/ISBN: 0301-1542 PMID: 8583713 Document Number: 452158
To assess the utility of measuring lung surfactant protein A (SP-A) in serum, a newly developed SP-A kit (Teijin TDR-30) was used at four facilities to measure serum SP-A levels in patients with various lung diseases. Serum SP-A levels in healthy volunteers were 24.6 +/- 9.6 ng/ml (mean +/- SD). serum SP-A levels did not differ significantly between different age groups (thirties through seventies). A cut-off level of 43.8 ng/ml was calculated, based on the values of the healthy volunteers. The serum SP-A levels in patients with idiopathic interstitial pneumonia (IIP: 67.9 +/- 42.5 ng/ml), pulmonary alveolar proteinosis (PAP: 7.0 +/- 45.7 ng/ml), and collagen disease with interstitial pneumonia (CDIP: 55.3 +/- 37.9 ng/ml) were significantly higher than those in healthy volunteers. When calculated with the cut-off value stated above, the positive rate of diagnosis for IIP was 71.4%. SP-A levels correlated closely with the clinical course; SP-A levels rose significantly during exacerbations of IIP. Measurement of SP-A in serum is useful for the diagnosis of IIP, PAP, and CDIP, and for monitoring exacerbations of IIP.