Room: Track 1
Purpose: The influence of e-cigarette on human lung is not well understood. In this study, we attempt to quantify early-stage pulmonary pathophysiology of the airways, interstitium, and capillary flow using hyperpolarized 129Xe MRI (Xe129 MRI) in young healthy e-cigarette users.
Methods: Five young healthy subjects (age=22.4±3.9, FEV1%pred=99.8±5.9%, FEV1/FVC=82.2±5.6) with minimal 6-month use of e-cigarette (JUUL), ten young healthy controls (age=22.1±2.6, FEV1%pred=101.1±8.9%, FEV1/FVC=83.5±6.2), and ten older healthy controls (age=58.4±13.8, FEV1%pred=100.1±9.1%, FEV1/FVC=75.8±4.2) underwent Xe129 MRI. Xe129 MRI provides information about ventilation in the lung using the ventilation defect percentage (VDP), and about gas exchange using the signal from dissolved xenon, including the tissue-to-gas ratio (T/G) reflecting gas-exchange capacity of the interstitial tissue compartment, and the RBC(red blood cells) -to-gas ratio (R/G) reflecting pulmonary gas exchange of the RBCs in the capillary compartment, and RBC-to-tissue ratio reflects gas transfer from interstitium to the blood. Xe129 MRI results in JUUL users were compared quantitatively with controls.
Results: Ventilation was similar between JUUL users and healthy controls as measured by VDP (healthy controls 18.6±9.4% vs. JUUL 13.6±4.0%, p=0.185). Gas-exchange capacity of the interstitial tissue was significantly lost in JUUL users as compared to healthy controls regardless of their ages (T/G 0.857±0.332% vs. 1.111±0.188%, p=0.044). However, total gas-exchange capacity into the RBCs in the capillaries was preserved in JUUL users as compared to healthy controls regardless of their ages (R/G 0.357±0.124% vs. 0.331±0.080%, p=0.754). Preservation of the total gas-exchange capacity was explained by the fact that significantly increased gas transfer from the interstitial tissues to the capillary RBCs was found in JUUL users as compared to healthy controls regardless of their ages (R/T 0.425±0.074% vs. 0.296±0.050%, p<0.001).
Conclusion: JUUL use in healthy young adults caused significant lost in gas-exchange capacity of the interstitium and abnormally increased gas transfer from the interstitium to the capillary RBCs.
Funding Support, Disclosures, and Conflict of Interest: Co-author Xue Feng is employee of Carina Medical, LLC, Lexington, KY, and receives salary support. This project is supported by R21HL129112 and R01HL132177