Comparison of Exhaled Endogenous Particles from Smokers and Non-Smokers Using Multivariate Analysis

• Background: Smoking, along with many respiratory diseases, has been shown to induce airway inflammation and alter the composition of the respiratory tract lining fluid (RTLF). We have previously shown that the phospholipid and protein composition of particles in exhaled air (PEx) reflects that of RTLF. In this study, we hypothesized that the composition of PEx differs between smokers and non-smokers, reflecting inflammation in the airways. Objective: It was the aim of this study to identify differences in the phospholipid composition of PEx from smokers and non-smokers. Methods: PEx from 12 smokers and 13 non-smokers was collected using a system developed in-house. PEx was analysed using time-of-flight secondary ion mass spectrometry, and the mass spectral data were evaluated using multivariate analysis. Orthogonal partial least squares (OPLS) was used to relate smoking status, lung function and pack years to the chemical composition of RTLF. The discriminating ions identified by OPLS were then used as explanatory variables in traditional regression analysis. Results: There was a clear discrimination between smokers and non-smokers according to the chemical composition, where phospholipids from smokers were protonated and sodiated to a larger extent. Poor lung function showed a strong association with higher response from all molecular phosphatidylcholine species in the samples. Furthermore, the accumulated amount of tobacco consumed was associated with variations in mass spectra, indicating a dose-response relationship. Conclusion: The chemical composition of PEx differs between smokers and nonsmokers, reflecting differences in the RTLF. The results from this study may suggest that the composition of RTLF is affected by smoking and may be of importance for lung function.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Public Health, Global Health, Social Medicine and Epidemiology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Lungmedicin och allergi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Respiratory Medicine and Allergy (hsv//eng)

Keyword

Cigarette smoking

Inflammation

Orthogonal partial least squares

Particles in exhaled air

OBSTRUCTIVE PULMONARY-DISEASE

ION MASS-SPECTROMETRY

TOF-SIMS SPECTRA

LUNG SURFACTANT

PHOSPHOLIPID-COMPOSITION

BRONCHOALVEOLAR LAVAGE

METABOLOMICS DATA

INFORMATION

PROTEINS

ASTHMA

Publication and Content Type

ref (subject category)

art (subject category)