Analysis of additional lung fluid samples confirms the presence of vitamin E acetate in patients with electronic-cigarette, or vaping, product use–associated lung injury, according to a report on 51 patients in 16 states.
The average age of the patients was 23 years; 69% were male.
The report extends previous work by the Centers for Disease Control and Prevention to test for harmful substances in bronchoalveolar-lavage (BAL) fluid obtained from patients with electronic-cigarette, or vaping, product use–associated lung injury (EVALI) as part of a strategy to understand and manage the recent outbreak of EVALI cases in the United States, wrote Benjamin C. Blount, PhD, of the Division of Laboratory Sciences at the CDC’s National Center for Environmental Health, and colleagues.
“CDC was addressing a serious outbreak of lung injury that was sometimes lethal; but after the first 10 weeks of the outbreak investigation, the cause was still unknown,” Dr. Blount said in an interview. “Possible theories could not be evaluated unless the laboratory could develop tests that could confidently connect exposure to lung injury. Detection of toxicants in bronchoalveolar-lavage fluid from patients with EVALI can provide direct information on exposure within the lung.”
In a study published in the New England Journal of Medicine, the researchers examined the BAL of 51 cases of EVALI from 16 states. They analyzed the samples for multiple toxicants, including vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates, and diluent terpenes.
Overall, 77% of the patients reported using products containing THC, 67% reported using products containing nicotine, and 51% reported using both types.
Researchers found vitamin E acetate in 48 of the 51 patients (94%); no vitamin E acetate was found in the BAL of healthy controls. Coconut oil and limonene were found in one patient each, but none of the other toxicants was found in the samples from the patients or controls.
In addition, 47 of the 50 patients for whom data were available either had detectable tetrahydrocannabinol (THC) or its metabolites in their BAL fluid samples, or they reported vaping THC products within 90 days before they became ill. Nicotine or its metabolites were found in 30 of 47 patients (64%).
The study findings were limited by several factors, including the potential role of vitamin E acetate as a marker for exposure to other toxicants, the uncertainty of the role of aerosolized constituents formed when vitamin E acetate is heated, and the lack of data on the timing and burden of toxicant exposure, the investigators noted.
As for the next steps in research, “additional studies are needed to examine the respiratory effects of inhaling aerosolized vitamin E acetate and provide information on whether vitamin E acetate in isolation causes lung injury,” Dr. Blount explained. Analysis of the aerosol and gases generated by case-associated product fluids is ongoing.
“When CDC developed the BAL study for this response, we considered several possible toxicants in this investigation to find a possible cause of the outbreak,” Dr. Blount noted. “To accomplish the study, CDC’s Environmental Health Laboratory developed 12 analytical methods and validated them in less than 3 weeks because of the urgent nature of the emergency.”
Dr. Blount said he would advise clinicians to “continue to reference CDC guidance on treating suspected or EVALI patients.” In December, the CDC published updated guidance for clinicians on hospitalized EVALI patients. “Following this guidance and other recommendations could reduce EVALI-associated morbidity and mortality,” Dr. Blount said.
The study was supported in part by the National Cancer Institute, the FDA Center for Tobacco Products, and Ohio State University Pelotonia Intramural Research. The researchers had no financial conflicts to disclose.
SOURCE: Blount BC et al. N Engl J Med. 2020 Feb 20. doi: 10.1056/NEJMoa1916433.