Measuring Compounds in Exhaled Air to Detect Alzheimer's Disease and Parkinson's Disease

PLoS One. 2015 Jul 13;10(7):e0132227. doi: 10.1371/journal.pone.0132227. eCollection 2015.

Abstract

Background: Alzheimer's disease (AD) is diagnosed based upon medical history, neuropsychiatric examination, cerebrospinal fluid analysis, extensive laboratory analyses and cerebral imaging. Diagnosis is time consuming and labour intensive. Parkinson's disease (PD) is mainly diagnosed on clinical grounds.

Objective: The primary aim of this study was to differentiate patients suffering from AD, PD and healthy controls by investigating exhaled air with the electronic nose technique. After demonstrating a difference between the three groups the secondary aim was the identification of specific substances responsible for the difference(s) using ion mobility spectroscopy. Thirdly we analysed whether amyloid beta (Aβ) in exhaled breath was causative for the observed differences between patients suffering from AD and healthy controls.

Methods: We employed novel pulmonary diagnostic tools (electronic nose device/ion-mobility spectrometry) for the identification of patients with neurodegenerative diseases. Specifically, we analysed breath pattern differences in exhaled air of patients with AD, those with PD and healthy controls using the electronic nose device (eNose). Using ion mobility spectrometry (IMS), we identified the compounds responsible for the observed differences in breath patterns. We applied ELISA technique to measure Aβ in exhaled breath condensates.

Results: The eNose was able to differentiate between AD, PD and HC correctly. Using IMS, we identified markers that could be used to differentiate healthy controls from patients with AD and PD with an accuracy of 94%. In addition, patients suffering from PD were identified with sensitivity and specificity of 100%. Altogether, 3 AD patients out of 53 participants were misclassified. Although we found Aβ in exhaled breath condensate from both AD and healthy controls, no significant differences between groups were detected.

Conclusion: These data may open a new field in the diagnosis of neurodegenerative disease such as Alzheimer's disease and Parkinson's disease. Further research is required to evaluate the significance of these pulmonary findings with respect to the pathophysiology of neurodegenerative disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / diagnosis*
  • Amyloid beta-Peptides / analysis
  • Animals
  • Biomarkers / analysis
  • Blotting, Western
  • Breath Tests* / methods
  • Case-Control Studies
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Lung / chemistry
  • Male
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Middle Aged
  • Parkinson Disease / diagnosis*
  • Peptide Fragments / analysis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spectrum Analysis / methods

Substances

  • Amyloid beta-Peptides
  • Biomarkers
  • Peptide Fragments
  • amyloid beta-protein (1-40)
  • amyloid beta-protein (1-42)

Grant support

This work was financed by a research grant from the Behring Röntgen Initiative awarded to ARK and JPB (Behring Röntgen Stiftung, Grant title: non-invasive diagnostic in patients with AD, Grant number: 56-0036). The funding source was not involved in study design, the collection, analysis and interpretation of the data, in writing of the report, and in the decision to submit the article for publication.