An in vitro evaluation of e-vapor products: The contributions of chemical adulteration, concentration, and device power

Homemade e-liquids and power-adjustable vaping devices may carry higher risks than commercial formulations and fixed-power devices. This study used human macrophage-like and bronchial epithelial (NHBE) cell cultures to investigate toxicity of homemade e-liquids containing propylene glycol and vegetable glycerin (PG/VG), nicotine, vitamin E acetate (VEA), medium-chain fatty acids (MCFAs), phytol, and cannabidiol (CBD). SmallAir™ organotypic epithelial cultures were exposed to aerosols generated at different power settings (10-50 W). Carbonyl levels were measured, and endpoints reflecting epithelial function (ciliary beating frequency [CBF]), integrity (transepithelial electrical resistance [TEER]), and structure (histology) were investigated. Treatment with nicotine or VEA alone or with PG/VG did not impact cell viability. CBD, phytol, and lauric acid caused cytotoxicity in both culture systems and increased lipid-laden macrophages. Exposure of SmallAir™ organotypic cultures to CBD-containing aerosols resulted in tissue injury and loss of CBF and TEER, while PG/VG alone or with nicotine or VEA did not. Aerosols generated with higher power settings had higher carbonyl concentrations. In conclusion, the presence and concentration of certain chemicals and device power may induce cytotoxicity in vitro. These results raise concerns that power-adjustable devices may generate toxic compounds and suggest that toxicity assessments should be conducted for both e-liquid formulations and their aerosols.

Comparative study of lung toxicity of E-cigarette ingredients to investigate E-cigarette or vaping product associated lung injury

No comparative study has yet been performed on the respiratory effects of individual E-cigarette ingredients. Here, lung toxicity of individual ingredients of E-cigarette products containing nicotine or tetrahydrocannabinol was investigated. Mice were intratracheally administered propylene glycol (PG), vegetable glycerin (VG), vitamin E acetate (VEA), or nicotine individually for two weeks. Cytological and histological changes were noticed in PG- and VEA-treated mice that exhibited pathophysiological changes which were associated with symptoms seen in patients with symptoms of E-cigarette or Vaping Use-Associated Lung Injuries (EVALI) or E-cigarette users. Compared to potential human exposure situations, while the VEA exposure condition was similar to the dose equivalent of VEA content in E-cigarettes, the PG condition was about 47-137 times higher than the dose equivalent of the daily PG intake of E-cigarette users. These results reveal that VEA exposure is much more likely to cause problems related to EVALI in humans than PG. Transcriptomic analysis revealed that PG exposure was associated with fibrotic lung injury via the AKT signaling pathway and M2 macrophage polarization, and VEA exposure was associated with asthmatic airway inflammation via the mitogen-activated protein kinase signaling pathway. This study provides novel insights into the pathophysiological effects of individual ingredients of E-cigarettes.

The implications of Vitamin E acetate in E-cigarette, or vaping, product use-associated lung injury

In the summer of 2019, a cluster of cases were observed with users of battery-operated or superheating devices presenting with multiple symptoms, such as dyspnea, cough, fever, constitutional symptoms, gastrointestinal upset, and hemoptysis, that is now termed e-cigarette, or vaping, product use-associated lung injury (EVALI). The Centers for Disease Control and Prevention reported 2807 cases within the USA leading to at least 68 deaths as of February 18, 2020. The heterogeneous presentations of EVALI make diagnosis and treatment difficult; however, treatment focused on identifying and removal of the noxious substance and providing supportive care. Vitamin E acetate (VEA) is a likely cause of this lung injury, and others have reported other components to play a possible role, such as nicotine and vegetable glycerin/propylene glycol. EVALI is usually observed in adolescents, with a history of vaping product usage within 90 days typically containing tetrahydrocannabinol, and presenting on chest radiograph with pulmonary infiltrates or computed tomography scan with ground-glass opacities. Diagnosis requires a high degree of suspicion to diagnose and exclusion of other possible causes of lung disease. Here, we review the current literature to detail the major factors contributing to EVALI and primarily discuss the potential role of VEA in EVALI. We will also briefly discuss other constituents other than just VEA, as a small number of EVALI cases are reported without the detection of VEA, but with the same clinical diagnosis.

Exploring the potential neurotoxicity of vaping vitamin E or vitamin E acetate

Serious adverse health effects have been reported with the use of vaping products, including neurologic disorders and e-cigarette or vaping product use-associated lung injury (EVALI). Vitamin E acetate, likely added as a diluent to cannabis-containing products, was linked to EVALI. Literature searches were performed on vitamin E and vitamin E acetate-associated neurotoxicity. Blood brain barrier (BBB) penetration potential of vitamin E and vitamin E acetate were evaluated using cheminformatic techniques. Review of the literature showed that the neurotoxic potential of inhalation exposures to these compounds in humans is unknown. Physico-chemical properties demonstrate these compounds are lipophilic, and molecular weights indicate vitamin E and vitamin E acetate have the potential for BBB permeability. Computational models also predict both compounds may cross the BBB via passive diffusion. Based on literature search, no experimental nonclinical studies and clinical information on the neurotoxic potential of vitamin E via inhalation. Neurotoxic effects from pyrolysis by-product, phenyl acetate, structurally analogous to vitamin E acetate, suggests vitamin E acetate has potential for central nervous system (CNS) impairment. Cheminformatic model predictions provide a theoretical basis for potential CNS permeability of these inhaled dietary ingredients suggesting prioritization to evaluate for potential hazard to the CNS.

Can social media monitoring help identify the next EVALI? An examination of Reddit posts about vitamin E acetate and Dank Vapes

BACKGROUND

Scientists identified vitamin E acetate (VEA) and "Dank Vapes" (a fake brand of tetrahydrocannabinol [THC] vaping products) as contributors to the 2019-2020 outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI). On social media, people who post about vaping or THC discussed the causes of EVALI. We examined whether Reddit conversations may have served as early signals of the outbreak.

METHODS

We collected Reddit posts from March 2018 to February 2020 on vaping- and THC-related subreddits that mentioned VEA or Dank Vapes. We identified peaks in post volume, examined post content, and used natural language processing to identify terms most characteristic of posts.

RESULTS

There were almost no posts about VEA before EVALI. Subsequently, there were two peaks, both referencing media coverage of scientific findings that linked VEA to EVALI. Discussion regularly referenced concerns about the legitimacy of Dank Vapes before EVALI; peaks in posts were largely unrelated to scientific findings or media coverage of those findings. The terms most characteristic of VEA posts were EVALI-related; those most characteristic of Dank Vapes posts were about quality or legitimacy.

CONCLUSIONS

Although posts about VEA and Dank Vapes did not predict the outbreak, the public health community could use social media to encourage people who vape or use THC to report future health concerns (e.g., through FDA's Safety Reporting Portal). Researchers and regulators could also use social media to see if potentially problematic products, such as Dank Vapes, have a history of concern among individuals who use those products.

Liquid chromatography-tandem mass spectrometry method for measuring vitamin E acetate in bronchoalveolar lavage fluid

We investigated the suitability of isotope-dilution liquid chromatography coupled with tandem mass spectrometry for identifying vitamin E acetate (VEA) in bronchoalveolar lavage (BAL) fluid. This new method demonstrates high accuracy, selectivity, and sensitivity, with mean recoveries higher than 90%, coefficients of variation ranging from 1.5% to 4.5%, and a limit of detection of 1.10 ng/mL. Calibration curves were linear (R² > 0.99). The linear range and detection limit of the method were adequate for identifying VEA in 48 of 51 BAL fluid samples collected from people with lung injury resulting from e-cigarettes, or vaping, product use. We conclude that this method is an effective tool for studying VEA accumulation in lungs caused by using e-cigarettes, or vaping, products that contain VEA.

The role of vitamin E acetate (VEA) and its derivatives in the vaping associated lung injury: systematic review of evidence

Small scale observational evidence suggested that Vitamin E (VE) might play beneficial role in human and animal respiratory conditions of various origin by stabilizing surfactant functions. The intra-aleveolar VE level is directly proportionate to the lung's response to inflammation. Electronic cigarette or vaping associated lung injury was a dominantly respiratory syndrome in the United States with seemingly strong association between potential Vitamin E acetate inhalation exposure and the onset of symptoms. This systematic review intended to assess if there was previous evidence of any potential respiratory/gastrointestinal toxicity associated with Vitamin E acetate or any of its derivatives. A systematic review was constructed and prospectively registered at PROSPERO to search important clinical databases between 2000 and 2020 for full text human articles investigating the effect of VEA or any of its derivatives administered via any route (oral/parenteral/aerosolised) in adults with any respiratory conditions. Out of 363 records investigating the effect of VEA and/or its derivatives/isomers in (any) lung injury (inflammatory, oxidative, infective, asthma/COPD) seven articles qualified. The papers reported various surrogate outcomes (APACHEII score, spirometry, etc) with equivocal results. There was one case report of harmful exposure to both Vitamin E (intramuscular) and Vitamin E acetate (topical). The present review found evidence of neither harm nor any significant clinical improvement associated with the administration of VEA or any derivatives via any route in adult inflammatory lung conditions however, the articles were of low-level evidence. Further studies are needed to correct flaws in research to explore the role of Vitamin E in pulmonology.

Examining the temporality of vitamin E acetate in illicit THC-containing e-cigarette, or vaping, products from a public health and law enforcement response to EVALI - Utah, 2018-2020

BACKGROUND

In the summer of 2019, e-cigarette, or vaping, product use-associated lung injury (EVALI) was detected in the United States. Multiple agencies reported illicit tetrahydrocannabinol (THC)-containing e-cigarette, or vaping, products containing vitamin E acetate (VEA) as a substance of concern.

METHODS

As an expansion of the Utah Department of Health's response to EVALI, the Utah Public Health Laboratory and the Utah Department of Public Safety screened 170 products from 96 seizures between October 2018 and January 2020. Using Pearson's correlation coefficient, we analyzed the temporal correlation of national, and Utah specific case counts, and the percentage of seizures indicating VEA by month.

RESULTS

The findings indicate strong and significant correlations between seizures indicating VEA and both the national (r = 0.70, p = 0.002) and Utah specific (r = 0.78, p < 0.001) case counts.

CONCLUSION

These findings underscore that VEA should not be added to e-cigarettes, or vaping, products and the importance of collaboration with law enforcement when responding to outbreaks associated with illicit substances.

E-cigarette or vaping product use-associated lung injury in the pediatric population: imaging features at presentation and short-term follow-up

BACKGROUND

Cases of e-cigarette or vaping product use-associated lung injury (EVALI) have rapidly reached epidemic proportions, yet there remain limited reports within the literature on the associated imaging findings.

OBJECTIVE

We describe the most common imaging findings observed on chest computed tomography (CT) and chest radiograph (CXR) at presentation and at short-term follow-up at our major pediatric hospital.

MATERIALS AND METHODS

A retrospective review of the electronic medical records was performed on all patients with suspected EVALI who were treated at a major pediatric hospital and 11 patients were included for analysis. Two board-certified pediatric radiologists then categorized the CXRs as either normal or abnormal, and further performed a systematic review of the chest CTs for imaging findings in the lungs, pleura and mediastinum. Interrater discordance was reconciled by consensus review.

RESULTS

The 11 patients (9 males:2 females) ranged in age from 14 to 18 years. Gastrointestinal and constitutional symptoms were present in all patients, whereas shortness of breath and cough were reported in 5/11 and 6/11 patients, respectively. The CXR was abnormal in 10/11 patients, whereas all chest CTs were abnormal. The most common CT findings included consolidation, ground-glass opacities, interlobular septal thickening, lymphadenopathy and crazy-paving pattern. Almost all patients demonstrated subpleural sparing, and less than half also demonstrated peribronchovascular sparing. There was complete or near-complete resolution of imaging abnormalities in 5/6 patients with a median follow-up duration of 114 days.

CONCLUSION

Pulmonary opacities with subpleural and peribronchovascular sparing was a commonly observed pattern of EVALI in the pediatric population at this institution. A CXR may not be sufficiently sensitive in diagnosing EVALI, and radiologists and clinicians should exercise caution when excluding EVALI based on the lack of a pulmonary opacity. Caution should also be exercised when excluding EVALI solely based on the lack of respiratory symptoms. Despite extensive pulmonary involvement at presentation, findings may resolve on short-term follow-up imaging.