Yoder: 'Hopefully our work may help prioritize further study of these two chemicals'

Researchers have reportedly made a significant discovery regarding the potential effects of PFAS chemicals on the body's innate immune system.

PFAS, or per- and polyfluoroalkyl substances, are a class of chemicals frequently used in the production of consumer and industrial goods to enhance their resistance to stains, grease and water, according to a news release form North Carolina State University. Researchers found PFAS chemical GenX can suppress the neutrophil respiratory burst, a critical process employed by white blood cells known as neutrophils to eradicate invading pathogens.

“It’s pretty well-established that PFAS are toxic to the adaptive immune system, but there hasn’t been as much research done on their effects on the innate immune system,” Drake Phelps, a former PhD student at North Carolina State University and first author of the study, said in the release.

In a recent study, they found the PFAS chemical GenX suppresses the neutrophil respiratory burst, a crucial mechanism used by white blood cells to eliminate invading pathogens, and the research is shedding light on how both legacy and emerging PFAS chemicals may impact the immune system, highlighting the need for further investigation into their long-term effects, the release reported

The researchers noted the human immune system is divided into two branches, the innate immune system that serves as the body's first line of defense, mobilizing white blood cells to the site of incursion within hours, while the adaptive immune system includes T cells and B cells and offers a delayed defense response, taking days or even weeks to react to pathogens, according to the release.

The while blood cells include neutrophils, which can release reactive oxygen species right onto pathogens, rendering them neutralized in a process known as respiratory burst, the release reported.

The researchers looked at the effects of nine environmentally relevant legacy and emerging PFAS on neutrophils, which were extracted from human neutrophils cultured from donor blood, zebrafish embryos and neutrophil-like cells, the release said.

The researchers noted that, of the PFAS chemicals tested, only GenX showed an ability to hold down the neutrophil respiratory burst in the trio of models, with PFHxA, another PFAS chemical, showing similar traits, but just in zebrafish embryos and neutrophil-like cells, according to the release.

Additionally, the researchers found the study’s results may generate more questions than they answer, and Jeff Yoder, a professor of comparative immunology at North Carolina State and a corresponding author of the study, pointed out more research is needed, adding that the longest chemical exposure in the study was four days, no comparison to a human exposure that covers four decades, the release said.

“So while we can say that we see a toxic effect from a high dose in the cell lines, we can’t yet say what effects long-term exposure may ultimately have on the immune system,” Yoder said in the release. “This paper isn’t the end of the road – it’s the first step. Hopefully our work may help prioritize further study of these two chemicals.”

The study, which also included Jamie DeWitt, a professor of pharmacology and toxicology at East Carolina University, as a co-author, was published in the Journal of Immunotoxicology, and it received support from the North Carolina State University Center for Environmental and Health Effects of PFAS, the National Institute of Environmental Health Sciences and the North Carolina State University Center for Human Health and the Environment, the release said.