I have not personally got that excited about microplastics, but this was an interesting paper that I forgot to highlight.
https://onlinelibrary.wiley.com/doi/epdf/10.1002/jca.70135
chatGPT:
Summary
The paper asks whether therapeutic plasma exchange (TPE) can lower the amount of circulating microplastics in human blood. It reports results from 174 single-plasma-volume TPE procedures in 114 patients, mostly treated in outpatient functional-medicine clinics, with blood microplastics measured immediately before and after TPE using the commercial PlasticTox assay.
The main finding is threshold-dependent:
| Starting microplastic level | Result after TPE | Interpretation |
|---|---|---|
| 0–9 MP / 100 μL | rose from mean 4.4 to 14.4 | apparent net addition of microplastics |
| 10–19 MP / 100 μL | fell slightly from 13.8 to 11.8, not significant | removal and contamination roughly balanced |
| 20–29 MP / 100 μL | fell from 23.6 to 16.1, significant | modest net removal |
| ≥30 MP / 100 μL | fell from 52.2 to 21.1, significant | clear net removal |
The authors interpret this as evidence that TPE can remove microplastics from blood, but that the procedure itself may also introduce microplastics, probably from plastic tubing, saline bags, albumin bottles, or other disposable components. This is supported by their finding that saline sampled from the apheresis tubing and bags already contained measurable microplastics.
The most striking point is therefore not simply “plasma exchange removes microplastics,” but rather:
TPE appears to remove circulating microplastics when the starting burden is high, but in people with low starting microplastic levels, the procedure may increase the measured burden because of contamination/leaching from the apheresis system itself.
Identified novelty
The paper’s novelty is fairly clear:
-
First intentional therapeutic attempt to reduce circulating microplastics in humans
Previous work had detected microplastics in blood and in plasmapheresis eluate, but this paper claims to be the first to show purposeful reduction of circulating microplastics using TPE. -
Human pre/post intervention data
The study is not merely observational detection of microplastics; it measures paired blood samples before and after a procedure. -
Identification of a contamination threshold problem
The paper’s most useful contribution may be its demonstration that the procedure can be counterproductive at low baseline levels because the plastic medical system itself appears to contribute microplastics. -
Practical implication for device design
It points to the need for lower-shedding tubing, bags, filters, and apheresis consumables before this could become a credible detoxification intervention.
Critique
The paper is interesting, but the evidence is preliminary and has major limitations.
1. No control group
There is no sham procedure, no non-TPE comparison group, and no repeated blood sampling without TPE. That makes it hard to separate the effect of the procedure from assay variability, sample handling, regression to the mean, or short-term biological fluctuation.
2. The assay is proprietary
The PlasticTox assay is central to the paper, but the authors state that validation data are proprietary. That is a major weakness. For a new and contamination-prone measurement such as blood microplastics, the credibility of the result depends heavily on transparent validation, recovery rates, blank controls, polymer identification, reproducibility, and contamination control.
3. Nile Red fluorescence is not definitive polymer identification
Nile Red staining can help detect hydrophobic particles, but it is not equivalent to full chemical identification by methods such as Raman spectroscopy, FTIR, or pyrolysis-GC/MS. Without polymer-level confirmation, there is a risk of misclassifying non-plastic particles as microplastics.
4. Contamination control appears inadequate for such a sensitive endpoint
The paper itself shows measurable microplastics in saline and tubing samples. That is important, but it also underlines how hard this experiment is to interpret. Microplastic studies require very rigorous procedural blanks, air controls, sampling-material controls, and laboratory contamination controls. The paper gives some evidence of tubing contamination, but not enough to fully quantify or correct for it.
5. The patient population is not a conventional clinical cohort
Most procedures were done for “support of longevity” in functional-medicine outpatient clinics, with other indications including POTS, ME/CFS and long Covid. This is not necessarily a problem, but it limits generalisability and raises questions about selection bias.
6. Repeated observations are treated partly like independent procedures
Some patients contributed more than one TPE measurement. The paper reports 174 procedures in 114 patients. Repeated measures from the same person are not fully independent, so analysis ideally should account for clustering by patient.
7. No evidence of clinical benefit
The paper measures circulating microplastic counts, not health outcomes. It does not show that lowering blood microplastics improves inflammation, vascular function, symptoms, disease risk, or ageing-related endpoints.
8. Blood burden may not equal body burden
The authors correctly acknowledge this. Even if TPE lowers microplastics in the bloodstream, it is unknown whether microplastics in tissues equilibrate with blood in a way that would allow repeated TPE to meaningfully lower total body burden.
9. Nanoplastics are not addressed
The assay threshold is about 1 μm, so the study does not determine whether TPE removes smaller nanoplastics, which may be biologically important.
Overall assessment
This is a provocative early clinical report rather than a definitive therapeutic study. Its strongest claim is that TPE can reduce measured circulating microplastics when baseline levels are high. Its most important caution is that in people with low starting burdens, the procedure may increase measured microplastics, probably due to leaching from plastic medical equipment.
The paper is useful because it exposes both sides of the issue: apheresis may remove some circulating particles, but the same medical procedure may also introduce new plastic particles unless the device pathway is redesigned and independently validated.