Calling it a “breakthrough,” the agency says it found vitamin E acetate in all 29 samples of lung fluid from patients with vaping-related lung injury. But it also cautions that it needs more answers to fully explain the mysterious illness that has sickened 2,051 people and killed 40.
Vitamin E acetate has long been thought to play a role in the outbreak. WebMD and other news outlets reported in September that doctors and others were finding vitamin E traces in the cartridges that patients had vaped. New York health officials launched an investigation in early September. Now, federal officials have tested actual samples taken from the lungs of patients.
Anne Schuchat, MD, the CDC's principal deputy director, says the finding is significant because it is “the first direct evidence of vitamin E acetate at the primary site of the injury."
Vitamin E acetate is an additive in the production of e-cigarette, or vaping, products and a thickening agent in THC products.
Schuchat says the findings do not rule out the possibility that other substances could also be playing a role in the illness, known as EVALI (e-cigarette, or vaping, product use-associated lung injury). More research is also needed to prove cause and effect, she says.
While most cases of EVALI have been linked to illicit THC, Schuchat says there are anecdotal reports of patients who bought from licensed dispensaries. And some cases have been reported in patients who vape nicotine only, she says.
Other research presented by public health officials at a Friday briefing found that people who get EVALI are much more likely to buy black market products, especially a class of largely counterfeit products called Dank Vapes.
Expert Perspective on the Finding
Laura Crotty Alexander, MD, a vaping researcher and associate professor of medicine at the University of California at San Diego, says they will continue researching vitamin E.
Many groups studying the outbreak have mentioned vitamin E, she says, but have not found it in every single sample as the CDC did. Even so, she cautions that "Just because the vitamin E is there doesn't mean it is the cause; it might be something that's traveling with it."
She says examining the fluid from the lungs is better evidence than testing the e-liquids. "The e–liquids, before being heated and aerosolized, have less than half the total number of chemicals that your lungs actually see. The fact they are looking at the chemical profile in the lung is a more powerful method. They are looking at the chemicals that actually reach the lungs."
Details on the Samples
In the new CDC investigation, researchers collected specimens during a procedure called bronchoalveolar lavage.
They found no detectable levels for the other substances, including plant oils, medium chain triglycerides, petroleum distillates, and terpenes (aromatic oils found in cannabis).
While 29 samples may seem like a small number, a bronchoscopy is needed to get the lung fluid, says Milton Teske, MD, a public health officer in Kings County, CA, and an emergency room doctor at Adventist Health, Hanford, CA. A doctor puts a thin and bendable tube through the mouth or nose into the lungs; a light and small camera on the tube let the doctor look inside the airways and get samples of mucus or tissue. In the lungs, vitamin E acetate is sticky, like honey, the CDC says.
Who Gets EVALI?
People who develop EVALI are twice as likely to report exclusive use of THC-containing products, compared to those who vape but do not develop the lung injury, according to research released by the Illinois Department of Health and CDC researchers at the briefing.
EVALI patients were three times as likely to vape often (more than five times a day) and more than nine times as likely to get the product from a dealer, off the street, or from a friend. Patients were 8½ times more likely to use Dank Vapes, a class of largely counterfeit-containing products, than people who stayed healthy.