Inflammatory phenotype modulation in the respiratory tract and systemic circulation of e-cigarette users: a pilot...

Area of Science:

• Immunology
• Respiratory Medicine
• Toxicology

Background:

• E-cigarette use is widespread, but its long-term health effects, particularly on inflammation and immunity, remain unclear.
• Understanding the impact of e-cigarette aerosol inhalation on host defenses is crucial for public health.

Purpose of the Study:

• To investigate changes in the inflammatory profile and monocyte function in chronic e-cigarette users.
• To evaluate the effects of reduced e-cigarette use on these inflammatory markers and immune cell responses.

Main Methods:

• A longitudinal pilot study involving e-cigarette users and healthy controls.
• Analysis of saliva, sputum, and blood samples for 38 proteins using multiplex assays.
• Assessment of circulating monocyte inflammatory responses to bacterial lipopolysaccharide.

Main Results:

• E-cigarette users showed decreased immunomodulatory proteins in airways and elevated cytokines/chemokines in circulation compared to controls.
• Specific alterations included lower IL-1 receptor antagonist (IL-1Ra) in saliva, higher IL-1Ra and GRO in sputum, and elevated TNFβ and VEGF in plasma.
• Monocytes from e-cigarette users exhibited blunted IL-8 and IL-6 release, indicating impaired response to bacterial challenge.

Conclusions:

• Chronic inhalation of e-cigarette aerosols significantly alters the inflammatory state in airways and systemic circulation.
• These alterations raise concerns for increased susceptibility to inflammatory and infectious diseases in long-term e-cigarette users.
• Reduced e-cigarette use may partially reverse some of these detrimental immune effects.