Smoking reduces surfactant protein D and phospholipids in patients with and without chronic obstructive pulmonary disease

BMC Pulm Med. 2010 Oct 25;10:53. doi: 10.1186/1471-2466-10-53.

Abstract

Background: Pulmonary surfactant D (SP-D) has important regulatory functions for innate immunity and has been implicated as a biomarker for chronic obstructive pulmonary disease (COPD). We hypothesized that COPD patients would have reduced bronchoalveolar lavage (BAL) fluid SP-D levels compared to healthy smoking and non-smoking controls.

Methods: BAL SP-D and phospholipids were quantified and corrected for dilution in 110 subjects (65 healthy never smokers, 23 smokers with normal spirometry, and 22 smokers with COPD).

Results: BAL SP-D was highest in never smokers (mean 51.9 μg/mL ± 7.1 μg/mL standard error) compared to both smokers with normal spirometry (16.0 μg/mL ± 11.8 μg/mL) and subjects with COPD (19.1 μg/mL ± 12.9 μg/mL; P < 0.0001). Among smokers with COPD, BAL SP-D correlated significantly with FEV1% predicted (R = 0.43; P < 0.05); however, the strongest predictor of BAL SP-D was smoking status. BAL SP-D levels were lowest in current smokers (12.8 μg/mL ± 11.0 μg/mL), intermediate in former smokers (25.2 μg/mL ± 14.2 μg/mL; P < 0.008), and highest in never smokers. BAL phospholipids were also lowest in current smokers (6.5 nmol ± 1.5 nmol), intermediate in former smokers (13.1 nmol ± 2.1 nmol), and highest in never smokers (14.8 nmol ± 1.1 nmol; P < 0.0001).

Conclusions: These data suggest that smokers, and especially current smokers, exhibit significantly reduced BAL SP-D and phospholipids compared to nonsmokers. Our findings may help better explain the mechanism that leads to the rapid progression of disease and increased incidence of infection in smokers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Biomarkers / metabolism
  • Bronchoalveolar Lavage Fluid / chemistry
  • Female
  • Humans
  • Lung / metabolism
  • Lung / physiopathology
  • Male
  • Middle Aged
  • Phospholipids / metabolism*
  • Pulmonary Disease, Chronic Obstructive / metabolism*
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Pulmonary Surfactant-Associated Protein D / analysis
  • Pulmonary Surfactant-Associated Protein D / metabolism*
  • Regression Analysis
  • Smoke / adverse effects
  • Smoking / adverse effects
  • Smoking / metabolism*
  • Spirometry
  • Young Adult

Substances

  • Biomarkers
  • Phospholipids
  • Pulmonary Surfactant-Associated Protein D
  • Smoke