Plasmapheresis works like this: blood is drawn from one arm, the plasma—the liquid portion of blood containing proteins, fats, and other substances—is separated, passed through special filters or adsorbers, and then returned purified to the body. At the University of Dresden, such procedures are performed up to 10,000 times a year. Researchers decided to test not only the standard indicators of the procedure's effectiveness but also to study the composition of the substances the device extracts from the blood and accumulates in the fraction separated after filtration.
Scientists were interested in two classes of pollutants found almost everywhere today: PFAS and micro- and nanoplastics. PFAS are used in the production of non-stick coatings, water-repellent clothing, packaging, and many other materials. These compounds are called "forever chemicals" due to their high stability—some can persist in the human body for several years. Microplastics, meanwhile, are found in blood, placenta, lungs, and other human tissues. Their long-term health effects are still being studied.
It is hypothesized that pollutants travel through the body along with fat and protein particles in the blood. PFAS and microplastic particles can become coated with a "corona" of plasma proteins and lipids—a shell that forms around foreign particles in the body.
This coating allows the particles to remain in the bloodstream longer. Some PFAS are known to bind to lipoproteins—complexes that transport fats and cholesterol. The researchers hypothesized that if the device removes lipoproteins from the blood, it may also capture some of the pollutants associated with them.
To test this hypothesis, the team analyzed blood samples from patients before and after the procedure. The study included 34 people undergoing plasmapheresis for medical reasons. Following the procedure, as expected, their levels of low-density lipoprotein (LDL), lipoprotein (a), and inflammatory markers decreased. However, additional mass spectrometry analysis revealed that the procedure also affected the concentration of certain PFAS. In one set of samples (14 patients), levels of individual compounds decreased by up to 25%.
An independent laboratory that tested samples from four people recorded a more significant reduction—in some cases, up to 75.8%. The same types of PFAS were detected in the fluid removed by the machine after filtration, indicating their removal from the bloodstream.
The situation with microplastics is more complex. In some blood samples, the procedure reduced the levels of certain polymers, such as polyethylene and polyvinyl chloride, but the changes were not consistent across different types of plastic. In a small experiment with four patients, the nanoparticle counting method showed an average reduction of approximately 70%, but the scientists note that the test used detects more than just plastics, so these data require confirmation by other methods. In two cases, an additional adsorption system was used to detect the removal of certain types of polymers, but the sample size was too small for definitive conclusions.
Researchers also received confirmation that microplastics can be found not only in blood, but also in human tissue.
Using Raman spectroscopy, they detected polystyrene particles in the eyelid tissue. This indicates that plastic particles can linger in the body rather than simply circulating in the bloodstream. It is not yet known whether plasmapheresis can affect such tissue accumulations.
The study's authors emphasize that the results should not be taken as proof of a "detox procedure" for removing harmful particles. The patient sample was small, and the cleansing method itself removes toxins only from circulating blood. Scientists do not know how long the effect lasts after the procedure or whether pollutants are re-circulated from tissues into the blood. Nevertheless, the study helps better understand how pollutants are distributed throughout the body.
