Abstract
Detection of alpha-synuclein (α-Syn) seeding activity in tear fluid (TF) offers a promising non-invasive biomarker for Parkinson’s disease (PD). α-Syn seeding amplification assay (αSynSAA) detected seeding activity in 67% of PD-TF, while non-synucleinopathy samples remained negative. Electron microscopy of seeding-positive end products revealed fibrillar structures morphologically consistent with results of αSynSAA. αSynSAA effectively distinguished PD from controls and prion diseases based on seeding activity in TF.
Data availability
The datasets generated and/or analyzed during the current study are not publicly available due to ongoing research that relies on the data, but are available from the corresponding author on reasonable request.
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Acknowledgements
The authors thank the Robert Koch Institute through funds from the Federal Ministry of Health (Grant No. 1369-341) to I.Z.
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M.S., P.L., and I.Z. conceived the study; S.C. performed experiments; S.C., M.S., and I.Z. analyzed data, interpreted results, and performed statistical analyses. M.S., F.M., P.P., and I.Z. acquired data and contributed to technical expertise. F.M., C.v.R., S.C., P.H., S.Z., and P.L. acquired biological samples. W.M. and B.P. performed TEM analysis. S.C., M.S., and I.Z. drafted the manuscript. All authors read and approved the manuscript.
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Canaslan, S., Schmitz, M., Maass, F. et al. Detection of alpha-synuclein seeding activity in tear fluid in patients with Parkinson’s disease. npj Parkinsons Dis. (2026). https://doi.org/10.1038/s41531-026-01282-2
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DOI: https://doi.org/10.1038/s41531-026-01282-2
