A Cholesterol-Filtering Treatment Also Pulled "Forever Chemicals" Out of Patients' Blood

The machine has been sitting in hospital treatment rooms for about four decades, quietly doing one job: pulling stubborn cholesterol out of the blood of patients whose bodies won't respond to pills. Doctors in Dresden just asked what else might be coming out with it, and the answer surprised them.

~4,700 PFAS compounds
The number of per- and polyfluoroalkyl substances in commercial or environmental use today, none of which the body can easily break down, which is why they're nicknamed "forever chemicals."

Why does this matter?

PFAS chemicals, used for decades in nonstick cookware, waterproof fabric, and firefighting foam, resist breaking down and now turn up in the blood of nearly everyone tested worldwide. Microplastics, tiny plastic fragments shed from packaging and textiles, have similarly been found in human tissue in recent years. Both are suspected of contributing to metabolic and neurological problems, but doctors currently have no approved way to reduce a person's existing body burden of either. If a treatment already used on thousands of patients happens to remove some of it, that would matter well beyond the small group who need it for cholesterol.

What did the researchers find?

A team led by endocrinologist Stefan Bornstein at Technische Universität Dresden, whose center performs up to 10,000 apheresis treatments a year, tested blood before and after sessions. Apheresis draws blood out, separates the plasma, filters it through a membrane or adsorption column to strip out cholesterol-carrying lipoproteins, and returns the cleaned plasma to the patient. The researchers reasoned that if PFAS and microplastics travel through the body bound to fats and proteins, the same filter that removes cholesterol might catch them too.

Using mass spectrometry, they confirmed several PFAS compounds showed up in the filtered-out material, meaning they were physically leaving the bloodstream. Two independent labs found the same pattern. The microplastic results were messier: for some polymer types, particle counts actually rose in certain patients after treatment rather than falling, something the researchers can't yet fully explain.

What don't we know yet?

Bornstein was blunt about the limits of the work: there was no randomized controlled trial, and the study does not show the treatment clears plastic already lodged in tissue, only what showed up in blood plasma during a single filtering session. Whether apheresis can reach pollutants deposited in organs, rather than just what's circulating at that moment, remains an open question.

What happens next?

Bornstein's team says its next step is testing the approach in large animals using radiotracer- or iron-labeled micro- and nanoplastics, then imaging where those particles sit in the body before and after apheresis, to see whether the treatment can actually pull pollutants out of tissue rather than just blood. Bornstein also cautioned that even if the method works, treating existing contamination will always be harder and more expensive than avoiding exposure in the first place.

For now, this is a filter that was never designed to catch forever chemicals catching them anyway, and doctors still don't fully understand how.