Highlights
Microplastics (MPs) were identified in thyroid tissues of both autoimmune thyroiditis (AIT) patients and controls, with significantly higher concentrations in AIT cases. Polyvinyl chloride (PVC) was notably elevated in AIT patients. Particle analysis revealed no morphological differences between groups, but abundance and chemical composition differed.
Background
Autoimmune thyroiditis (AIT) is the leading cause of hypothyroidism, affecting millions worldwide. Microplastics, pervasive environmental pollutants, have been found in various human tissues, but their presence in the thyroid and potential role in autoimmunity was previously unexplored. This study bridges a critical gap in understanding environmental triggers of thyroid dysfunction.
Study Design
This case-control study analyzed thyroid tissues from 29 histologically confirmed AIT patients and 29 age- and sex-matched controls with benign thyroid nodules. MPs were quantified using pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) and characterized via micro-Raman spectroscopy and scanning electron microscopy (SEM).
Key Findings
Total MP concentrations were significantly higher in AIT patients (median: 19.9 μg/g vs. 1.9 μg/g; p=0.012), with PVC being the predominant polymer. Micro-Raman spectroscopy showed higher MP abundance in AIT tissues (172 vs. 50.2 items/g, p=0.037), with particle sizes ranging from 33.9 to 1467 µm. Morphological features (size, shape, color) did not differ between groups.
Expert Commentary
“These findings suggest a plausible environmental contributor to thyroid autoimmunity,” notes Dr. Yu, lead author. “While causation isn’t established, the enrichment of PVC, a known endocrine disruptor, warrants further investigation into MPs’ immunomodulatory effects.” Study limitations include small sample size and lack of longitudinal exposure data.
Conclusion
This pioneering study links thyroid MP contamination, particularly PVC, to AIT, highlighting a potential environmental risk factor for autoimmune thyroid disease. Larger cohort studies and mechanistic research are needed to confirm these observations and explore intervention strategies.
Funding and Registration
Study funded by the National Natural Science Foundation of China. No clinical trial registration as it was a tissue analysis study.
References
Yu ST, Fu J, Fan Z, et al. Preliminary Evidence of Microplastics in the Human Thyroid and Their Potential Association with Autoimmune Thyroiditis. Thyroid. 2026;36(4):10507256261442506. PMID: 41961540.