Reply to Eissenberg and Maziak: Are Electronic Cigarette Users at Risk for Lipid-mediated Lung Injury?

From the Author:

The letter from Eissenberg and Maziak is a welcome reminder that although most of the cases of e-cigarette or vaping product use–associated lung injury (EVALI) have been associated with tetrahydrocannabinol (THC)-containing liquids, cases have also been reported in which only nicotine-containing liquids were used. As of December 17, 2019, a total of 2,506 hospitalized EVALI cases have been reported to the CDC from all 50 states, the District of Columbia, and two U.S. territories (Puerto Rico and the U.S. Virgin Islands), with 54 deaths in 27 states and the District of Columbia (1). Of 1,782 hospitalized patients for whom complete information was available on substances used in e-cigarette or vaping products in the 3 months before symptom onset, 13% reported exclusive use of nicotine-containing products (1). These data provide the basis for the CDC recommendation that “the best way for people to ensure that they are not at risk while the investigation continues is to consider refraining from the use of all e-cigarette, or vaping, products” (2). Since the publication of the Triantafyllou and colleagues case series and the accompanying editorial, more information has become available about the EVALI cases associated with vaping of a class of largely counterfeit THC-containing products of unknown origin, with “Dank Vapes” being the most common brand (3, 4). CDC laboratory test results of BAL fluid samples from 29 patients submitted to the CDC from 10 states found vitamin E acetate in all the samples (1). Vitamin E acetate is an oil used to thicken e-cigarette liquid. Although all the CDC BAL analyses were of THC-containing vape liquids, a recent report from South Korea showed vitamin E acetate present in nicotine-containing products, including JUUL pods (5). Eissenberg and Maziak suggest that lipid materials in e-cigarette liquids, particularly vegetable glycerin, are the likely cause of EVALI in patients who only used nicotine-containing products. Whether the lipid is vitamin E acetate or vegetable glycerin or another agent, inhaling lipid-containing aerosol generated by high heat can lead to the generation of lipid-laden macrophages, recently reported by Maddock and colleagues in cases of EVALI from Utah (6). Electronic nicotine delivery systems can play a beneficial role in tobacco smoking cessation, but only if the e-cigarette liquid is properly and safely prepared. I fully agree with Eissenberg and Maziak’s call for strict regulation of e-cigarette liquid contents.