Researchers are investigating whether the vaping-related illnesses that have been making headlines in the U.S. recently have been occurring undetected all along, reports Reuters.
Many of the recent victims reportedly had pockets of oil clogging up cells responsible for removing impurities in the lungs.
Researchers have begun to re-examine lung cell samples they have collected in recent years for evidence of these oil-filled immune cells in people who vaped but didn’t get sick.
Some suspect the oils are formed inside the lungs as part of the body’s natural response to chemicals found in many commercial vapor devices. One theory is that vaping these chemicals may impair the immune system and make people who vape more vulnerable to respiratory distress.
A study published in the Journal of Clinical Investigation earlier this month found that mice exposed to aerosols of propylene glycol and vegetable glycerin—common solvents used in conventional nicotine vapor devices—developed these same fat-clogged immune cells even though they were never exposed to vaping oils.
These mice also had impaired immune systems.