CDC researchers, gathering bronchoalveolar lavage (BAL) samples from 29 patients with lung injury tied to vaping, said they found vitamin E acetate in every single one.
The finding -- reported Friday in a special release -- returns the search for a common feature in these illnesses, and thus a potential cause, back almost where it started.
On Thursday, the CDC reported an for the vaping illness, which the agency has dubbed EVALI, topping 2,000 and a death toll of 39.
Investigations thus far have shown that a great majority of cases had histories of cannabis and particularly THC use, but in roughly 15%, the patients insisted they had used nicotine vaping products exclusively. Most, but not all, cases have been in men and in people younger than 30. But no single characteristic or activity had been seen in every case, frustrating efforts to identify causes.
In early September, just 3 weeks after the outbreak was announced, officials in New York state said they had found vitamin E acetate "in nearly all cannabis-containing [e-liquid] samples" they had analyzed. Moreover, "[a]t least one vitamin E acetate containing vape product has been linked to each patient who submitted a product for testing," according to . Vitamin E oil is said to be a .
But the finding was not confirmed in other labs, and vitamin E acetate looked like another dead end. Now, the new BAL study may be the smoking gun investigators have been searching for.
Led by Benjamin C. Blount, PhD, of the CDC's National Center for Environmental Health, researchers obtained BAL samples from EVALI patients in 10 states. Of the 29 patients providing samples, self-reports of vaping history were available from 23, and of those, all but three admitted to THC use. And for the three who didn't, their BAL samples tested positive for THC or its metabolites, Blount and colleagues said.
Of 26 samples tested for nicotine metabolites, 16 came back positive. Results for other e-liquid components such as petroleum distillates and plant oils "were all below analyte-specific levels of detection," the report indicated.
Only vitamin E acetate was found in all the samples. But Blount and colleagues noted a number of important limitations -- the patients undergoing BAL were a "convenience sample" and there were no control samples from other individuals. The researchers noted as well that vitamin E acetate hasn't been confirmed in animal studies to cause EVALI-like illness.