Fourth generation e-cigarette vaping induces transient lung inflammation and gas exchange disturbances: results from two randomized clinical trials

Recent updates on biomarkers of exposure and systemic toxicity in e-cigarette users and EVALI

Electronic nicotine delivery systems (ENDS), or e-cigarettes, are emerging tobacco products that produce aerosols by heating e-liquids, which most often consist of propylene glycol and vegetable glycerin along with various flavoring compounds, bypassing the combustion that occurs in the use of traditional tobacco cigarettes. These products have seen a drastic increase in popularity in recent years both as smoking cessation devices as well as among younger generations, due in large part to the widespread perception among consumers that e-cigs are significantly less harmful to health than traditional tobacco cigarettes. Due to the novelty of ENDS as well as their rapidly increasing use, research into biomarkers of e-cig exposure and toxicity have lagged behind their popularity, leaving important questions about their potential toxicity unanswered. Research into potential biomarkers of acute and chronic e-cig use, and e-cigarette- or vaping-associated lung injury is necessary for informing both clinical and regulatory decision-making. We aim to provide an updated review of recent research into potential circulating, genomic, transcriptomic, and epigenetic biomarkers of exposure to and toxicity of e-cigs. We additionally highlight research areas that warrant additional study to gain a better understanding of health risks associated with ENDS use, as well as to provide validation of existing data and methods for measuring and analyzing e-cig-associated biomarkers in human and animal biofluids, tissues, and cells. This review also highlights ongoing efforts within the WNY Center for Research on Flavored Tobacco for research into novel biomarkers in extracellular vesicles that may be associated with short- and long-term ENDS use.

E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies

Background

Use of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults, but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorders from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies.

Method

We conducted a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with COPD. We discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection and genetic expression.

Results

Epidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (aOR) was 1.39 (95% CI 1.28–1.51); for COPD (n=9 studies) the aOR was 1.49 (95% CI 1.36–1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls, although sometimes less than for cigarettes.

Conclusions

The evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose–response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of concern for respirology and public health.

Epidemiological studies show a relationship of e-cigarette use with asthma and COPD, and laboratory studies show their adverse effects on four biological processes. It can be concluded that e-cigarette use is of significant concern for public health.https://bit.ly/3drH4pj

Comparison of the chemical composition of aerosols from heated tobacco products, electronic cigarettes and tobacco cigarettes and their toxic impacts on the human bronchial epithelial BEAS-2B cells

The electronic cigarettes (e-cigs) and more recently the heated tobacco products (HTP) provide alternatives for smokers as they are generally perceived to be less harmful than conventional cigarettes. However, it is crucial to compare the health risks of these different emergent devices, in order to determine which product should be preferred to substitute cigarette. The present study aimed to compare the composition of emissions from HTP, e-cigs and conventional cigarettes, regarding selected harmful or potentially harmful compounds, and their toxic impacts on the human bronchial epithelial BEAS-2B cells. The HTP emitted less polycyclic aromatic hydrocarbons and carbonyls than the conventional cigarette. However, amounts of these compounds in HTP aerosols were still higher than in e-cig vapours. Concordantly, HTP aerosol showed reduced cytotoxicity compared to cigarette smoke but higher than e-cig vapours. HTP and e-cig had the potential to increase oxidative stress and inflammatory response, in a manner similar to that of cigarette smoke, but after more intensive exposures. In addition, increasing e-cig power impacted levels of certain toxic compounds and related oxidative stress. This study provides important data necessary for risk assessment by demonstrating that HTP might be less harmful than tobacco cigarette but considerably more harmful than e-cig.

Case of a 21-year-old man with persistent lung collapse leading to a pericardectomy linked to vape use

This case report describes multiple organ failure in a young man with illicit vape use which he did not initially disclose to his health care providers. His symptoms were not readily diagnosed until he experienced lung collapse and significant heart failure. Treatment plan recommendations varied among health care providers leading to increased anxiety for the patient and his family. It was ultimately determined that illicit vape use along with chronic substance abuse contributed to a respiratory virus causing pulmonary collapse. The pulmonary virus migrated to the patient's heart causing severe restrictive pericarditis ultimately requiring a pericardectomy. Assessment, interventions, and follow-up care occurred during the global Corona-19 pandemic of 2020.

Smoking, Vaping, and the Benefits Cessation in Times of COVID-19: A Public Health Perspective

The goal of this article is to inform dental practitioners and specialists of the benefits of smoking and vaping cessation in relation to COVID-19 transmission. COVID-19 caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has affected more than 31.7 million people globally with infection rates continuing to rise rapidly. Smoking dramatically impairs lung function and gives rise to an increase in susceptibility for infection, allowing for a more difficult recovery due, in part, to the damage SARS-CoV-2 does to the lungs. Tobacco smoking is one of the primary causes of death in the United States (US), however, nearly 40 million adults still smoke cigarettes, with 4.7 million middle and high school students using at least one tobacco product, including electronic cigarettes. COVID-19 is transmitted through salivary droplets, causing severe bilateral pneumonia and significantly reduced lung function, putting smokers and vapers at greater risk through cross-contamination and face touching. So far, data from animal studies suggest that vaping leads to an increased susceptibility to infection, which coincides with evidence of increased rates of chronic bronchitis in vapers. There is yet to be data regarding the benefits of smoking and vaping cessation during the COVID-19 pandemic. However, there is evidence suggesting that 4 weeks or more of smoking cessation intervention reduces the risk of contracting COVID-19 and developing severe complications. Because of these probable connections, dental practitioners should advise their patients to stop smoking and/or vaping via the 5 As Cessation Strategy.

Acute e-cig inhalation impacts vascular health: a study in smoking naïve subjects

This study was designed to investigate the acute effects of nonnicotinized e-cigarette (e-cig) aerosol inhalation in nonsmokers both in terms of blood-based markers of inflammation and oxidative stress and evaluate their association with hemodynamic-metabolic MRI parameters quantifying peripheral vascular reactivity, cerebrovascular reactivity, and aortic stiffness. Thirty-one healthy nonsmokers were subjected to two blood draws and two identical MRI protocols, each one before and after a standardized e-cig vaping session. After vaping, the serum levels of C-reactive protein, soluble intercellular adhesion molecule, and the danger signal machinery high-mobility group box 1 (HMGB1) and its downstream effector and the NLR family pyrin domain containing 3 (NLRP3) inflammasome (as monitored by its adaptor protein ASC) increased significantly relative to the respective baseline (prevaping) values. Moreover, nitric oxide metabolites and reactive oxygen species production decreased and increased, respectively. These observations were paralleled by impaired peripheral vascular reactivity (with reduced flow-mediated dilation and attenuated hyperemic response after a cuff-occlusion test) and metabolic alterations expressed by decreased venous oxygen saturation, postvaping. The current results suggest propagation of inflammation signaling via activation of the danger signaling axis (HMGB1-NLRP3). The findings indicate that a single episode of vaping has adverse impacts on vascular inflammation and function.NEW & NOTWORTHY Endothelial cell signaling and blood biomarkers were found to correlate with functional vascular changes in a single episode e-cigarettes inhalation in healthy adults. This is indicative of the potential of e-cigarettes (even when inhaled acutely) to lead of vascular dysfunction.

Vaping disrupts ventilation-perfusion matching in asymptomatic users

Inhalation of e-cigarette's aerosols (vaping) has the potential to disrupt pulmonary gas exchange, but the effects in asymptomatic users are unknown. We assessed ventilation-perfusion (V̇_A/Q̇) mismatch in asymptomatic e-cigarette users, using magnetic resonance imaging (MRI). We hypothesized that vaping induces V̇_A/Q̇ mismatch through alterations in both ventilation and perfusion distributions. Nine young, asymptomatic "Vapers" with >1-yr vaping history, and no history of cardiopulmonary disease, were imaged supine using proton MRI, to assess the right lung at baseline and immediately after vaping. Seven young "Controls" were imaged at baseline only. Relative dispersion (SD/means) was used to quantify the heterogeneity of the individual ventilation and perfusion distributions. V̇_A/Q̇ mismatch was quantified using the second moments of the ventilation and perfusion versus V̇_A/Q̇ ratio distributions, log scale, LogSDV̇, and LogSDQ̇, respectively, analogous to the multiple inert gas elimination technique. Spirometry was normal in both groups. Ventilation heterogeneity was similar between groups at baseline (Vapers, 0.43 ± 0.13; Controls, 0.51 ± 0.11; P = 0.13) but increased after vaping (to 0.57 ± 0.17; P = 0.03). Perfusion heterogeneity was greater (P = 0.04) in Vapers at baseline (0.53 ± 0.06) compared with Controls (0.44 ± 0.10) but decreased after vaping (to 0.42 ± 0.07; P = 0.005). Vapers had greater (P = 0.01) V̇_A/Q̇ mismatch at baseline compared with Controls (LogSDQ̇ = 0.61 ± 0.12 vs. 0.43 ± 0.12), which was increased after vaping (LogSDQ̇ = 0.73 ± 0.16; P = 0.03). V̇_A/Q̇ mismatch is greater in Vapers and worsens after vaping. This suggests subclinical alterations in lung function not detected by spirometry.NEW & NOTEWORTHY This research provides evidence of vaping-induced disruptions in ventilation-perfusion matching in young, healthy, asymptomatic adults with normal spirometry who habitually vape. The changes in ventilation and perfusion distributions, both at baseline and acutely after vaping, and the potential implications on hypoxic vasoconstriction are particularly relevant in understanding the pathogenesis of vaping-induced dysfunction. Our imaging-based approach provides evidence of potential subclinical alterations in lung function below thresholds of detection using spirometry.

E-cigarette use and respiratory disorders: an integrative review of converging evidence from epidemiological and laboratory studies

BACKGROUND

Use of electronic cigarettes (e-cigarettes) is prevalent among adolescents and young adults, but there has been limited knowledge about health consequences in human populations. We conduct a systematic review and meta-analysis of results on respiratory disorders from studies of general-population samples and consider the mapping of these results to findings about biological processes linked to e-cigarettes in controlled laboratory studies.

METHOD

We conducted a literature search and meta-analysis of epidemiological studies on the association of e-cigarette use with asthma and with COPD. We discuss findings from laboratory studies about effects of e-cigarettes on four biological processes: cytotoxicity, oxidative stress/inflammation, susceptibility to infection and genetic expression.

RESULTS

Epidemiological studies, both cross-sectional and longitudinal, show a significant association of e-cigarette use with asthma and COPD, controlling for cigarette smoking and other covariates. For asthma (n=15 studies), the pooled adjusted odds ratio (aOR) was 1.39 (95% CI 1.28-1.51); for COPD (n=9 studies) the aOR was 1.49 (95% CI 1.36-1.65). Laboratory studies consistently show an effect of e-cigarettes on biological processes related to respiratory harm and susceptibility to illness, with e-cigarette conditions differing significantly from clean-air controls, although sometimes less than for cigarettes.

CONCLUSIONS

The evidence from epidemiological studies meets established criteria for consistency, strength of effect, temporality, and in some cases a dose-response gradient. Biological plausibility is indicated by evidence from multiple laboratory studies. We conclude that e-cigarette use has consequences for asthma and COPD, which is of concern for respirology and public health.

All up in smoke: vaping-associated lung injury

The electronic cigarette (EC), was initially introduced as a safe alternative to conventional cigarette smoking While initially seemingly innocuous, over 2800 E-cigarette, or Vaping, product use-associated lung injury (EVALI) cases have been reported in the USA, with a spectrum of clinical severity ranging from mild dyspnea to overt respiratory failure In this report we highlight three EVALI cases whom presented with dyspnea and a variety of non-specific symptoms. Diagnostic imaging demonstrated bilateral reticular infiltrates and ground-glass opacities with lymphadenopathy. Clinically, patients failed to respond to empiric antibiotics but improved after initiating steroids. Consistent with prior case series, our patients reported exposure to EC liquids containing tetrahydrocannabinol (THC)/cannabidiols (CBD) additives, suggesting Vitamin E acetate as the potentially harmful constituent. In this case series and review, we not only summarize prior clinical studies that have evaluated the effects of vaping on cardiopulmonary function as well as case reports on EVALI, but also discuss the pathophysiology of vaping and EVALI. It remains unclear not only why some individuals develop EVALI, but why the clinical and pathological presentations vary. EVALI remains a significant public health concern and clinicians must maintain a high index of suspicion for this novel phenomenon.

Cell-specific toxicity of short-term JUUL aerosol exposure to human bronchial epithelial cells and murine macrophages exposed at the air-liquid interface

Backgroud

JUUL, an electronic nicotine delivery system (ENDS), which first appeared on the US market in 2015, controled more than 75% of the US ENDS sales in 2018. JUUL-type devices are currently the most commonly used form of ENDS among youth in the US. In contrast to free-base nicotine contained in cigarettes and other ENDS, JUUL contains high levels of nicotine salt (35 or 59 mg/mL), whose cellular and molecular effects on lung cells are largely unknown. In the present study, we evaluated the in vitro toxicity of JUUL crème brûlée-flavored aerosols on 2 types of human bronchial epithelial cell lines (BEAS-2B, H292) and a murine macrophage cell line (RAW 264.7).

Methods

Human lung epithelial cells and murine macrophages were exposed to JUUL crème brûlée-flavored aerosols at the air–liquid interface (ALI) for 1-h followed by a 24-h recovery period. Membrane integrity, cytotoxicity, extracellular release of nitrogen species and reactive oxygen species, cellular morphology and gene expression were assessed.

Results

Crème brûlée-flavored aerosol contained elevated concentrations of benzoic acid (86.9 μg/puff), a well-established respiratory irritant. In BEAS-2B cells, crème brûlée-flavored aerosol decreased cell viability (≥ 50%) and increased nitric oxide (NO) production (≥ 30%), as well as iNOS gene expression. Crème brûlée-flavored aerosol did not affect the viability of either H292 cells or RAW macrophages, but increased the production of reactive oxygen species (ROS) by ≥ 20% in both cell types. While crème brûlée-flavored aerosol did not alter NO levels in H292 cells, RAW macrophages exposed to crème brûlée-flavored aerosol displayed decreased NO (≥ 50%) and down-regulation of the iNOS gene, possibly due to increased ROS. Additionally, crème brûlée-flavored aerosol dysregulated the expression of several genes related to biotransformation, inflammation and airway remodeling, including CYP1A1, IL-6, and MMP12 in all 3 cell lines.

Conclusion

Our results indicate that crème brûlée-flavored aerosol causes cell-specific toxicity to lung cells. This study contributes to providing scientific evidence towards regulation of nicotine salt-based products.

Acute Respiratory Failure Associated With Vaping

The use of e-cigarettes to deliver aerosolized nicotine has gained popularity in recent years. Numerous reports have cited the development of acute pulmonary disease linked to vaping nicotine as well as marijuana-based products. As cultural attitudes evolve and policies shift toward the legalization of marijuana, its use has become more prevalent. Given the increased prevalence of marijuana consumption and e-cigarette usage, better insight into its potential to cause lung toxicity is warranted. The clinical, radiographic, and histopathologic characteristics of lung injury associated with vaping, particularly with marijuana-based products, have yet to be well described in the literature. We present eight patients, most of whom were admitted recently to our institution with acute respiratory failure following vaping. The majority of patients were young, with a median age of 31.5 years (range, 24-62 years) and with no known underlying lung disease. This case series highlights common clinical findings as well as the varied radiographic and histopathologic features of acute respiratory failure associated with vaping predominantly marijuana-based products. As more cases of vaping-associated pulmonary injury unfold, data will be available to further characterize this emerging disease entity. Improved understanding of disease pathogenesis and its clinical course will help clinicians determine optimal management and follow-up strategies for this patient population.

E-cigarette or vaping induced lung injury: A case series and literature review

Introduction

Recently, a rapidly increasing number of e-cigarette or vaping induced lung injury (EVALI) has been reported across the nation. Given the ongoing epidemic, it has been suggested that specific chemical substances used as additives in e-cigarettes could be highly related to EVALI. A history of vaping with positive radiographic changes and low suspicion for active infection are requirements for diagnosis but it still remains a diagnosis of exclusion. The course of the disease, mechanism of lung injury and the optimal management options need to be better understood. Here we aimed to discuss the clinical characteristics recognized in a case series of ten hospitalized EVALI patients with radiological findings of lung injury and provide an up today summary of the known literature of EVALI-induced lung injury.

Methods

A retrospective chart review was conducted on ten patients who presented to Saint Peter's University Hospital in New Brunswick, NJ from July 2019 to February 2020, with a mean hospital stay of five days. According to the CDC recommended definition of the disease, our cases met the current working definition of confirmed or probable cases of EVALI.

Results

Ten patients, with mean age 30.8 years (50 % male) and average years of vaping 1.708 with 60 % endorsing a simultaneous history of cannabis-related products use, went under a retrospective review. 3/10 (30 %) had documented medically-managed pulmonary disease history, 8/10 (80 %) presented with the respiratory-related chief complaint, 6/10 (60 %) presented with gastrointestinal symptoms and 7/10 (70 %) had constitutional symptoms. All patients (100 %) were found to have bilateral ground-glass opacities on chest imaging. 9/10 were admitted, 6/10 (60 %) had an oxygen saturation of <95 % requiring oxygen supplementation with 4/10 managed in the intensive care unit.

Conclusion

EVALI patients with radiological findings of lung injury, although mainly present respiratory symptoms, may very often appear with constitutional and gastrointestinal symptoms. Based on the existing literature and our data it is argued that EVALI may be misdiagnosed and that closer monitoring is required to determine optimal diagnostic and therapeutic management of this condition. Our data and the existing literature suggest that laboratory and epidemiologic findings can be contributory for the diagnosis of the disease.

The fog, the attractive and the addictive: pulmonary effects of vaping with a focus on the contribution of each major vaping liquid constituent

Vaping has become increasingly popular over the past decade. This pragmatic review presents the published biological effects of electronic cigarette vapour inhalation with a focus on the pulmonary effects. Special attention has been devoted to providing the documented effects specific to each major ingredient, namely propylene glycol/glycerol, nicotine and flavouring agents. For each ingredient, findings are divided according to the methodology used, being in vitro studies, animal studies and clinical studies. Finally, we provide thoughts and insights on the current state of understanding of the pulmonary effects of vaping, as well as novel research avenues and methodologies.

Smoking and COVID-19: Adding Fuel to the Flame

The coronavirus disease 2019 (COVID-19) pandemic, an infection caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), has led to more than 771,000 deaths worldwide. Tobacco smoking is a major known risk factor for severe illness and even death from many respiratory infections. The effects of smoking on COVID-19 are currently controversial. Here, we provide an overview of the current knowledge on the effects of smoking on the clinical manifestations, disease progression, inflammatory responses, immunopathogenesis, racial ethnic disparities, and incidence of COVID-19. This review also documents future directions of smoking related research in COVID-19. The current epidemiological finding suggests that active smoking is associated with an increased severity of disease and death in hospitalized COVID-19 patients. Smoking can upregulate the angiotensin-converting enzyme-2 (ACE-2) receptor utilized by SARS-CoV-2 to enter the host cell and activate a ‘cytokine storm’ which can lead to worsen outcomes in COVID-19 patients. This receptor can also act as a potential therapeutic target for COVID-19 and other infectious diseases. The COVID-19 pandemic sheds light on a legacy of inequalities regarding gender, racial, and ethnic health disparities associated with active smoking, thus, smoking cessation may help in improving outcomes. In addition, to flatten the COVID-19 curve, staying indoors, avoiding unnecessary social contact, and bolstering the immune defense system by maintaining a healthy diet/living are highly desirable.

Association of E-cigarettes with adolescent alcohol use and binge drinking-drunkenness: A systematic review and meta-analysis

Background: E-cigarette (ECIG) use has increased substantially in the past decade. Co-use of alcohol and ECIGS may have serious consequences in adolescents. Objectives: To evaluate the association of e-cigarettes (ECIGs) with alcohol use in adolescents. Methods: Searched databases included PubMed, EMBASE, CINAHL, PsycINFO, Web of Science, and gray literature. Studies were included if they contained a non-E-cigarette group (NON-ECIG), an ECIG group, detailed rates of alcohol use, binge drinking, or drunkenness and included adolescents. Two independent reviewers extracted data using MOOSE guidelines. Evidence quality across studies was assessed using Cochrane GRADE methodology. Summary effects of ECIG vs. NON-ECIG use on any alcohol use and a composite of binge drinking/drunkenness were calculated using a random-effects model. Results: 28 of 3768 initially identified studies were included: 25 cross-sectional, 3 cohort studies, N = 458,357 total subjects (49.6% females). Pooling of data showed that ECIG users had a higher risk for any alcohol use compared to NON-ECIG users (Odds Ratio/OR 6.62, 95% confidence interval/CI 5.67-7.72) and a higher rate of binge drinking/drunkenness compared to NON-ECIG users (OR 6.73, 95% CI 4.5 - 10.07). The subset of high school ECIG users had higher rates of alcohol use (OR 8.17, 95% CI 5.95-11.2) and binge drinking/drunkenness (OR 7.98, 95% CI 5.98-10.63) compared to NON-ECIG users. Conclusion: ECIG users had a higher risk of alcohol use and binge drinking/drunkenness compared to NON-ECIG users. Our findings indicate that interventions to reduce ECIG use should be coupled with measures to reduce alcohol use in adolescents.Abbreviations: ECIG: e-cigarettes; NON-ECIG: non e-cigarettes.

Tobacco, but Not Nicotine and Flavor-Less Electronic Cigarettes, Induces ACE2 and Immune Dysregulation

The COVID-19 pandemic caused by the SARS-CoV-2 virus, overlaps with the ongoing epidemics of cigarette smoking and electronic cigarette (e-cig) vaping. However, there is scarce data relating COVID-19 risks and outcome with cigarette or e-cig use. In this study, we mined three independent RNA expression datasets from smokers and vapers to understand the potential relationship between vaping/smoking and the dysregulation of key genes and pathways related to COVID-19. We found that smoking, but not vaping, upregulates ACE2, the cellular receptor that SARS-CoV-2 requires for infection. Both smoking and use of nicotine and flavor-containing e-cigs led to upregulation of pro-inflammatory cytokines and inflammasome-related genes. Specifically, chemokines including CCL20 and CXCL8 are upregulated in smokers, and CCL5 and CCR1 are upregulated in flavor/nicotine-containing e-cig users. We also found genes implicated in inflammasomes, such as CXCL1, CXCL2, NOD2, and ASC, to be upregulated in smokers and these e-cig users. Vaping flavor and nicotine-less e-cigs, however, did not lead to significant cytokine dysregulation and inflammasome activation. Release of inflammasome products, such as IL-1B, and cytokine storms are hallmarks of COVID-19 infection, especially in severe cases. Therefore, our findings demonstrated that smoking or vaping may critically exacerbate COVID-19-related inflammation or increase susceptibility to COVID-19.

Clinical Features of E-cigarette, or Vaping, Product Use-Associated Lung Injury in Teenagers

BACKGROUND

In the United States in 2019, there was an outbreak of electronic cigarette, or vaping, product use-associated lung injury (EVALI). The manifestations of EVALI in adolescents are not well characterized. We describe the diagnosis, evaluation, and management of EVALI in adolescents hospitalized at a tertiary care, university-affiliated children's hospital.

METHODS

A multidisciplinary committee developed an EVALI algorithm on the basis of guidelines from the Centers for Disease Control and Prevention. A retrospective chart review was conducted on patients diagnosed with EVALI. Descriptive analyses included sociodemographic characteristics, clinical presentation, laboratory and imaging results, pulmonary function testing, oxygen requirements, and clinic follow-up.

RESULTS

Thirteen hospitalized adolescents were diagnosed with confirmed or probable EVALI. The majority were female (54%) with a mean age of 15.9 years. Sixty-nine percent of patients presented with respiratory symptoms, whereas gastrointestinal symptoms were prominent in 85% of patients. Vaping Δ-9-tetrahydrocannabinol was reported in 92% of patients, and vaping nicotine was reported in 62% of patients. All had bilateral ground-glass opacities on the chest computed tomography (CT) scan. Treatment with glucocorticoids led to clinical improvement in 11 of 12 patients. Treatment with glucocorticoids led to improvement in both forced expiratory volume in 1 second and forced vital capacity (P < .05). Four patients required home oxygen on the basis of 6-minute walk test results.

CONCLUSIONS

Diagnosis of EVALI should be suspected on the basis of vaping history and clinical presentation. Glucocorticoid treatment led to an improvement in symptoms and lung function. The 6-minute walk test may help determine oxygen needs at discharge.

EVALI and the Pulmonary Toxicity of Electronic Cigarettes: A Review

Electronic cigarettes are a novel and emerging product increasingly used by the general public. However, despite their popularity, they remain poorly studied and with likely serious health risks. EVALI, or "electronic cigarette or vaping product use-associated lung injury," is a recently described entity at the forefront of current investigations. Though EVALI has been linked to vitamin E acetate, a constituent of THC vaping products, electronic cigarettes likely pose a host of other pulmonary toxicities. The presentation, diagnostic work-up, treatment, and pathophysiology of EVALI are herein described, as well as the general pulmonary toxicity profile of electronic cigarettes.

Review of Health Consequences of Electronic Cigarettes and the Outbreak of Electronic Cigarette, or Vaping, Product Use-Associated Lung Injury

Electronic cigarettes (e-cigarettes) are battery-operated devices to insufflate nicotine or other psychoactive e-liquid aerosols. Despite initial claims of e-cigarettes as a nicotine-cessation device, aggressive marketing of e-cigarettes has led to an explosion in adolescents' and young adults' use over the last few years. Coupled with a lack of adequate investigation and regulation of e-cigarettes, the USA is facing an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) starting in mid-2019. While little long-term health hazard data are available, the components and constituents of e-cigarettes may adversely impact health. Propylene glycol and glycerin are humectants (water-retaining excipients) that generate pulmonary irritants and carcinogenic carbonyl compounds (e.g., formaldehyde, acetaldehyde, and acrolein) when heated in e-cigarettes. Metals contained in heating coils and cartridge casings may leach metals such as aluminum, chromium, iron, lead, manganese, nickel, and tin. Flavoring agents are considered safe for ingestion but lack safety data for inhalational exposures. Diacetyl, a common buttery flavoring agent, has known pulmonary toxicity with inhalational exposures leading to bronchiolitis obliterans. In 2019, clusters of lung injury associated with e-cigarette use were identified in Wisconsin and Illinois. Patients with EVALI present with a constellation of respiratory, gastrointestinal, and constitutional symptoms. Radiographically, patients have bilateral ground glass opacifications. As of February 18, 2020, the Centers for Disease Control has identified 2807 hospitalized patients diagnosed with either "confirmed" or "probable" EVALI in the US. Currently, vitamin E acetate (VEA) used as a diluent in tetrahydrocannabinol vape cartridges is implicated in EVALI. VEA cuts tetrahydrocannabinol oil without changing the appearance or viscosity. When inhaled, pulmonary tissue lacks the mechanism to metabolize and absorb VEA, which may lead to its accumulation. While most EVALI patients were hospitalized, treatment remains largely supportive, and use of corticosteroids has been associated with clinical improvement. The outbreak of EVALI highlights the need for regulation of e-cigarette devices and e-liquids. Clinicians need to be aware of the health hazards of e-cigarettes and be vigilant in asking about vaping.

E-cigarettes and respiratory health: the latest evidence

The E-cigarette market continues to expand at an alarming rate with thousands of flavours available for purchase and continuously evolving devices. Now that it is a multi-billion dollar industry and one without stringent regulation, there is rising concern over the safety of vaping products. Since June 2019, over 2800 cases of E-cigarette-associated acute lung toxicity have been reported in the USA, over 60 of which resulted in death. Many argue that E-cigarettes offer a safer alternative to smoking, but we are evidently far from fully understanding the potential hazards that they pose to respiratory health. Although the risk of an outbreak in the UK has been considered low due to tighter E-cigarette regulations, we cannot fully eliminate the possibility of similar events occurring in the future. With evidence frequently emerging of the harmful effects of E-cigarettes to pulmonary health, there is an urgent need to define the long-term implications of vaping. Studies show that E-cigarette exposure can disrupt pulmonary homeostasis, with reports of gas exchange disturbance, reduced lung function, increased airway inflammation and oxidative stress, downregulation of immunity, and increased risk of respiratory infection. In this review, the latest research on the effect of E-cigarette use on respiratory health will be presented.

Vaping-Related Acute Parenchymal Lung Injury: A Systematic Review

The outbreak of vaping-related acute lung injury in the United States, named EVALI (e-cigarette or vaping product use associated acute lung injury), has reignited concerns about the health effects of vaping. Initial case reports of vaping-related lung injury date back to 2012, but the ongoing outbreak of EVALI began in the summer of 2019 and has been implicated in 2,807 cases and 68 deaths as of this writing. Review of the scientific literature revealed 216 patient cases that spanned 41 reports of parenchymal lung injury attributed to vaping. In this review, we detail the clinical, radiographic, and pathologic patterns of lung injury that are attributable to vaping and provide an overview of the scientific literature to date on the effects of vaping on respiratory health. Tetrahydrocannabinol was the most commonly vaped substance, and vitamin E acetate was found in BAL specimens from many affected individuals. However, no specific component or contaminant has been identified conclusively to date as the cause for the injury. Patients present with cough, dyspnea, constitutional symptoms, and GI symptoms. Radiologic and histopathologic findings demonstrate a spectrum of nonspecific acute injury patterns. A high index of suspicion combined with a good history are the keys to an accurate diagnosis. Treatment is supportive; the mortality rate is low, and most patients recover. Corticosteroids have been used with apparent success in patients with severe disease, but more rigorous studies are needed to clarify their role in the treatment of vaping-related lung injury.

Neurotoxicity of e-cigarettes

It appears that electronic cigarettes (EC) are a less harmful alternative to conventional cigarette (CC) smoking, as they generate substantially lower levels of harmful carcinogens and other toxic compounds. Thus, switching from CC to EC may be beneficial for smokers. However, recent accounts of EC- or vaping-associated lung injury (EVALI) has raised concerns regarding their adverse health effects. Additionally, the increasing popularity of EC among vulnerable populations, such as adolescents and pregnant women, calls for further EC safety evaluation. In this state-of-the-art review, we provide an update on recent findings regarding the neurological effects induced by EC exposure. Moreover, we discuss possible neurotoxic effects of nicotine and numerous other chemicals which are inherent both to e-liquids and EC aerosols. We conclude that in recognizing pertinent issues associated with EC usage, both government and scientific researchers must address this public health issue with utmost urgency.

Prevalence of Electronic Cigarette Use and its Determinants among 13-to-15-Year-Old Students in Greece: Results from the 2013 Global Youth Tobacco Survey (GYTS)

Electronic cigarette use has increased over the past decade. Its potential role in smoking cessation, in addiction and as a 'gateway' to tobacco smoking is subject to intense research. This cross-sectional study, carried out in 2013, aims to present the habits of students aged 13-15 in Greece with regard to e-cigarettes and investigate potential risk factors and the relationship between e-cigarettes, tobacco smoking and other nicotine products. It is the first such study to be carried out in Greece. The survey was based on the standardized methodology of the Global Youth Tobacco Survey. All potential associations were investigated using multiple logistic regression. In total 2.8% of the 4096 participating students were current e-cigarette users and 12.3% of them were ever users. E-cigarette use was associated with male gender, being older, current use of combustible tobacco products and e-cigarette use in the family. Ever e-cigarette use, being older, female gender and higher pocket money were associated with an increased susceptibility to tobacco smoking. E-cigarette prevalence in Greece in 2013 was similar to that of other, developed countries. The smoking and vaping habits of adolescents must be monitored in order to assess trends over time and whether any policy alterations are necessary.

The Dangers of Vaping

As our nation turns away from smoking tobacco and toward legalization of marijuana, vaporization of both plants has increased in popularity. There are medical and cultural implications of this new trend which are just recently being reported and investigated. The purpose of this article is to review the scientific and sociological literature as it pertains to the vaporization of both marijuana and tobacco products and the potential medical and cultural implications of this new phenomenon.

Pulmonary Toxicity and the Pathophysiology of Electronic Cigarette, or Vaping Product, Use Associated Lung Injury

New emerging tobacco products, especially electronic cigarettes (E-Cig) or electronic nicotine delivery systems (ENDS), have gained a huge popularity, particularly in younger populations. The lack of sufficient evidence-based health effect studies has promoted widespread use/abuse with the assumption that E-Cig or ENDS and/or vaping products are safer and less toxic than conventional tobacco smoking. However, the recent escalation in acute lung injuries and their associated fatalities among ENDS or vaping product users has now brought attention to this silent epidemic via investigation into the constituents of ENDS/vaping products and their toxic effects on pulmonary health. Accordingly, CDC has declared an “outbreak” of the e-cigarette or vaping product use associated lung injury (EVALI). EVALI is characterized by sterile exogenous pneumonitis like reaction with substantial involvement of innate immune mechanisms. Vitamin-E acetate (VEA) is found in counterfeit cartridges and bronchoalveolar lavage fluid of EVALI patients. Other reports implicated the presence of aromatic/volatile hydrocarbons and oils consisting of medium-chain triglycerides (MCT oil), including terpenes and mineral oil in tetrahydrocannabinol (THC) containing counterfeit vaping products. These compounds are involved in oxidative stress and inflammatory responses in the lung. Here, we provide the perspectives on the recent case reports on EVALI, etiology, and discuss pulmonary toxicity as well as the mechanisms underlying EVALI susceptibility and lung pathophysiology.

Diffuse Alveolar Hemorrhage: An Uncommon Manifestation of Vaping-associated Lung Injury

Vaping involves the use of a device to deliver aerosolized nicotine and tetrahydrocannabinol (THC) oils to the lungs. Vaping continues to increase in popularity; however, because it is a novel drug delivery system there is little evidence regarding its safety and long-term consequences. Here, we present a 22-year-old Caucasian male who was admitted with acute hypoxic respiratory failure and massive hemoptysis. Contrasted computed tomography of the chest demonstrated ground glass opacities throughout all lung fields and bilateral pulmonary emboli. Bronchoalveolar lavage revealed increased red blood cell counts in serial aliquots, consistent with the diagnosis of diffuse alveolar hemorrhage (DAH). An extensive workup did not reveal an etiology for the DAH. However, further history was obtained, and the patient divulged daily vaping of THC. E-cigarette, or vaping, product use associated lung injury (EVALI) consists of a myriad of different lung injury patterns. Our case illustrates an uncommon presentation of EVALI with DAH and multiple pulmonary emboli. 

Electronic Cigarettes and Cardiovascular Risk: Caution Waiting for Evidence

Electronic cigarettes use is a growing trend in contemporary societies, with the propensity to compete with traditional tobacco smoking. Some preclinical studies demonstrated the toxic and detrimental effects of electronic cigarettes liquid components. Its impact on human health remains unknown and insufficiently studied. While some studies suggest that electronic cigarettes use might be associated with endothelial dysfunction, impaired platelet function and increased risk of adverse clinical events, other studies did not confirm these findings and epidemiological data mostly suggest that the use of electronic cigarettes appears to be safer than that of traditional tobacco cigarettes. This article provides an up-to-date overview of the current state of knowledge regarding electronic cigarettes and their impact on human health, with special emphasis on their effect on cardiovascular diseases.

VpALI-Vaping-related Acute Lung Injury: A New Killer Around the Block

The use of electronic cigarettes, known as vaping, has become increasingly popular over the past decade, particularly in the adolescent and young adult population, often exposing users to harmful chemicals. Vaping has been associated with a heterogeneous group of pulmonary disease. Recently, a multistate epidemic has emerged surrounding vaping-related acute lung injury, prompting the Centers for Disease Control and Prevention to list an official health advisory. In this review, we describe the current literature on the epidemiology, clinical significance, as well as recommended evaluation and treatment of vaping-related lung injury.

Short halt in vaping modifies cardiorespiratory parameters and urine metabolome: a randomized trial

Propylene glycol and glycerol are e-cigarette constituents that facilitate liquid vaporization and nicotine transport. As these small hydrophilic molecules quickly cross the lung epithelium, we hypothesized that short-term cessation of vaping in regular users would completely clear aerosol deposit from the lungs and reverse vaping-induced cardiorespiratory toxicity. We aimed to assess the acute effects of vaping and their reversibility on biological/clinical cardiorespiratory parameters [serum/urine pneumoproteins, hemodynamic parameters, lung-function test and diffusing capacities, transcutaneous gas tensions (primary outcome), and skin microcirculatory blood flow]. Regular e-cigarette users were enrolled in this randomized, investigator-blinded, three-period crossover study. The periods consisted of nicotine-vaping (nicotine-session), nicotine-free vaping (nicotine-free-session), and complete cessation of vaping (stop-session), all maintained for 5 days before the session began. Multiparametric metabolomic analyses were used to verify subjects' protocol compliance. Biological/clinical cardiorespiratory parameters were assessed at the beginning of each session (baseline) and after acute vaping exposure. Compared with the nicotine- and nicotine-free-sessions, a specific metabolomic signature characterized the stop-session. Baseline serum club cell protein-16 was higher during the stop-session than the other sessions (P < 0.01), and heart rate was higher in the nicotine-session (P < 0.001). Compared with acute sham-vaping in the stop-session, acute nicotine-vaping (nicotine-session) and acute nicotine-free vaping (nicotine-free-session) slightly decreased skin oxygen tension (P < 0.05). In regular e-cigarette-users, short-term vaping cessation seemed to shift baseline urine metabolome and increased serum club cell protein-16 concentration, suggesting a decrease in lung inflammation. Additionally, acute vaping with and without nicotine decreased slightly transcutaneous oxygen tension, likely as a result of lung gas exchanges disturbances.

What are the respiratory effects of e-cigarettes?

Electronic cigarettes (e-cigarettes) are alternative, non-combustible tobacco products that generate an inhalable aerosol containing nicotine, flavors, propylene glycol, and vegetable glycerin. Vaping is now a multibillion dollar industry that appeals to current smokers, former smokers, and young people who have never smoked. E-cigarettes reached the market without either extensive preclinical toxicology testing or long term safety trials that would be required of conventional therapeutics or medical devices. Their effectiveness as a smoking cessation intervention, their impact at a population level, and whether they are less harmful than combustible tobacco products are highly controversial. Here, we review the evidence on the effects of e-cigarettes on respiratory health. Studies show measurable adverse biologic effects on organ and cellular health in humans, in animals, and in vitro. The effects of e-cigarettes have similarities to and important differences from those of cigarettes. Decades of chronic smoking are needed for development of lung diseases such as lung cancer or chronic obstructive pulmonary disease, so the population effects of e-cigarette use may not be apparent until the middle of this century. We conclude that current knowledge of these effects is insufficient to determine whether the respiratory health effects of e-cigarette are less than those of combustible tobacco products.

Recurrent spontaneous pneumothoraces and vaping in an 18-year-old man: a case report and review of the literature

Background

Primary spontaneous pneumothorax is a common disorder occurring in young adults without underlying lung disease. Although tobacco smoking is a well-documented risk factor for spontaneous pneumothorax, an association between electronic cigarette use (that is, vaping) and spontaneous pneumothorax has not been noted. We report a case of spontaneous pneumothoraces correlated with vaping.

Case presentation

An 18-year-old Caucasian man presented twice with recurrent right-sided spontaneous pneumothoraces within 2 weeks. He reported a history of vaping just prior to both episodes. Diagnostic testing was notable for a right-sided spontaneous pneumothorax on chest X-ray and computed tomography scan. His symptoms improved following insertion of a chest tube and drainage of air on each occasion. In the 2-week follow-up visit for the recurrent episode, he was asymptomatic and reported that he was no longer using electronic cigarettes.

Conclusions

Providers and patients should be aware of the potential risk of spontaneous pneumothorax associated with electronic cigarettes.

Application of a multi-layer systems toxicology framework for in vitro assessment of the biological effects of Classic Tobacco e-liquid and its corresponding aerosol using an e-cigarette device with MESH™ technology

We previously proposed a systems toxicology framework for in vitro assessment of e-liquids. The framework starts with the first layer aimed at screening the potential toxicity of e-liquids, followed by the second layer aimed at investigating the toxicity-related mechanism of e-liquids, and finally, the third layer aimed at evaluating the toxicity-related mechanism of the corresponding aerosols. In this work, we applied this framework to assess the impact of the e-liquid MESH Classic Tobacco and its aerosol compared with that of cigarette smoke (CS) from the 3R4F reference cigarette. In the first layer, we evaluated the cytotoxicity profile of the MESH Classic Tobacco e-liquid (containing humectants, nicotine, and flavors) and its Base e-liquid (containing humectant and nicotine only) in comparison with total particulate matter (TPM) of 3R4F CS using primary bronchial epithelial cell cultures. In the second layer, the same culture model was used to explore changes in specific markers using high-content screening assays to identify potential toxicity-related mechanisms induced by the MESH Classic Tobacco and Base e-liquids beyond cell viability in comparison with the 3R4F CS TPM-induced effects. Finally, in the third layer, we compared the impact of exposure to the MESH Classic Tobacco or Base aerosols with 3R4F CS using human organotypic air-liquid interface buccal and small airway epithelial cultures. The results showed that the cytotoxicity of the MESH Classic Tobacco liquid was similar to the Base liquid but lower than 3R4F CS TPM at comparable nicotine concentrations. Relative to 3R4F CS exposure, MESH Classic Tobacco aerosol exposure did not cause tissue damage and elicited lower changes in the mRNA, microRNA, and protein markers. In the context of tobacco harm reduction strategy, the framework is suitable to assess the potential-reduced impact of electronic cigarette aerosol relative to CS.

Dysregulated repair and inflammatory responses by e-cigarette-derived inhaled nicotine and humectant propylene glycol in a sex-dependent manner in mouse lung

Nicotine inhalation via electronic cigarettes (e‐cigs) is an emerging concern. However, little is known about the acute toxicity in the lungs following inhalation of nicotine‐containing e‐cig aerosols. We hypothesized that acute exposure to aerosolized nicotine causes lung toxicity by eliciting inflammatory and dysregulated repair responses. Adult C57BL/6J mice were exposed 2 hours daily for 3 days to e‐cig aerosols containing propylene glycol (PG) with or without nicotine. Acute exposure to nicotine‐containing e‐cig aerosols induced inflammatory cell influx (neutrophils and CD8a⁺ T lymphocytes), and release of pro‐inflammatory cytokines in bronchoalveolar lavage fluid in a sex‐dependent manner. Inhalation of e‐cig aerosol containing PG alone significantly augmented the lung levels of various homeostasis/repair mediators (PPARγ, ADRP, ACTA2, CTNNB1, LEF1, β‐catenin, E‐cadherin, and MMP2) in a sex‐dependent manner when compared to air controls. These findings were accompanied by an increase in protein abundance and altered gene expression of lipogenic markers (PPARγ, ADRP) and myogenic markers (fibronectin, α‐smooth muscle actin and β‐catenin), suggesting a dysregulated repair response in mouse lungs. Furthermore, exposure to nicotine‐containing e‐cig aerosols or PG alone differentially affected the release of pro‐inflammatory cytokines in healthy and COPD human 3D EpiAirway tissues. Overall, acute exposure to nicotine‐containing e‐cig aerosols was sufficient to elicit a pro‐inflammatory response and altered mRNA and protein levels of myogenic, lipogenic, and extracellular matrix markers in mouse lung in a sex‐dependent manner. Thus, acute exposure to inhaled nicotine via e‐cig leads to dysregulated repair and inflammatory responses, which may lead to airway remodeling in the lungs.