title: Serum surfactant protein-A, but not surfactant protein-D or KL-6, can predict preclinical lung damage induced by smoking.
abstract: Serum surfactant protein (SP)-A offers a useful clinical marker for interstitial lung disease (ILD). However, SP-A is occasionally elevated in non-ILD pulmonary patients. The present study was conducted to investigate factors that affect serum SP- A levels in respiratory medicine. Serum SP-A, serum SP-D, serum Klebs von den Lungen (KL)-6 and pulmonary function tests were evaluated in 929 patients (current smokers, n=255; ex-smokers, n=242; never-smokers, n=432) without ILD or pulmonary alveolar proteinosis. Serum SP-A was significantly higher in current smokers than in never- or ex-smokers (p<0.01 and p<0.05, respectively). Serum SP- A was significantly higher in chronic obstructive pulmonary disease (COPD) and pulmonary thromboembolism than in other diseases (p<0.01). Serum SP-A correlated positively with amount of smoking (p<0.01) and negatively with forced expiratory volume in 1 s/forced vital capacity (p<0.05). Serum SP-D and KL-6 were unaffected by smoking. Smoking should be taken into account when evaluating serum SP-A levels, and different baseline levels of serum SP-A should be established for smokers and non-smokers. Serum SP-A may also represent a useful marker for predicting COPD in the preclinical stage.
authors.affiliation: Division of Pulmonary Medicine, Department of Medicine, National Defense Medical College, Tokorozawa, Japan. kobahide@ndmc.ac.jp
authors.forename: Hideo
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Soichiro
authors.initials: S
authors.lastname: Kanoh
authors.forename: Kazuo
authors.initials: K
authors.lastname: Motoyoshi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D008171:Lung Diseases / Q000097:blood; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood*; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood; D037662:Pulmonary Surfactant-Associated Protein A / Q000097:blood*; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood*; D012129:Respiratory Function Tests; D012907:Smoking / Q000097:blood* / Q000473:pathology; D016540:Smoking Cessation
chemical_list: D015415:Biomarkers; C060192:MUC1 protein, human; D018396:Mucin-1; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D