Therapeutic Apheresis May Lower PFAS and Microplastic Levels in Blood

Researchers in Germany examined blood from patients undergoing therapeutic apheresis—a double-filtration plasmapheresis used for severe cardiovascular disease. By comparing samples taken immediately before and after the procedure, they observed that circulating concentrations of several per- and polyfluoroalkyl substances (PFAS) declined, and that microplastic particles were sometimes captured by the filters. The findings were reported in the 2026 issue of *Brain Health*.

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The primary cohort comprised 14 patients who received two double-filtration sessions. Four common PFAS were measured before and after each session. In the immediate post-procedure samples, PFAS levels fell by as much as 25 %. A separate laboratory that re-analyzed samples from four patients using an alternative method reported average reductions ranging from 43.5 % to 75 %.

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Microplastic results were less uniform. Among four patients, polyethylene levels decreased in all, polyvinyl chloride declined in three, while other polymers showed mixed changes; some circulating plastic levels even rose after treatment. The investigators also detected microplastic fragments in material washed from used filters, indicating that particles can be retained by the apheresis system.

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The team hypothesizes two possible pathways. First, PFAS and microplastics may become trapped directly within the apheresis filters. Second, these pollutants could bind to lipoproteins or plasma proteins, forming aggregates that are co-removed alongside the intended lipid targets.

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The study’s small, partly overlapping patient groups and differing analytical methods preclude direct comparison of the reported percentage reductions. Measurement of microplastics is vulnerable to environmental contamination, and the observed increases in some polymer levels may reflect such artefacts or release from the tubing and fluid bags used during the procedure. Moreover, the research did not assess the durability of the reductions or any clinical health outcomes. Larger, controlled trials with standardized measurements and longer follow-up are required before therapeutic apheresis could be recommended as a treatment for PFAS or microplastic exposure.

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“Our current hypothesis is that these environmental pollutants are retained directly within the apheresis filters or that they form aggregates or complexes with lipoproteins and plasma proteins, allowing them to be co-removed during the procedure,” — Charlotte Steenblock, of the Dresden University of Technology

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