Five neuropeptides in body fluids could enable early Parkinson's disease diagnosis before motor symptoms appear | Research

The takeaway

Neuropeptides α-synuclein, substance P, neurotensin, NPY, and somatostatin in CSF, blood, saliva, tears, and urine show diagnostic potential for early PD detection, with levels correlating with disease severity and distinguishing PD from other conditions.

5 biomarkers in 5 body fluids
Neuropeptides detectable in blood, saliva, tears, urine, and CSF could enable early PD diagnosis before motor symptoms—when neuroprotective treatment is most effective

What the researchers found

5 neuropeptide biomarkers: α-synuclein, substance P, neurotensin, NPY, somatostatin. Measurable in: CSF, blood, saliva, tears, urine. Levels differ in PD. Correlate with severity. Distinguish PD from other conditions. ELISA detection.

Why it matters

PD is diagnosed too late—typically after 50-80% of dopamine neurons are already lost. Neuropeptide biomarkers in easily accessible fluids (blood, saliva) could detect PD years earlier, enabling neuroprotective intervention.

How the study worked

Narrative review of neuropeptide biomarker potential for early PD diagnosis.

What this study cannot tell us

Review format. Individual studies small. Neuropeptide levels overlap between PD and controls. No single biomarker is sufficient. Multi-marker panels likely needed.

How to read the evidence

Narrative review of diagnostic biomarker studies. Promising candidates needing prospective validation.

When this study was published

Published in 2025.

The bigger picture

A simple blood or saliva test for PD would revolutionize neurology. This review identifies the most promising neuropeptide candidates and calls for their integration into diagnostic practice.

Questions still open

Which neuropeptide panel provides the best diagnostic accuracy?
Can salivary neuropeptide testing replace invasive CSF sampling?
Would neuropeptide screening enable preventive PD treatment?

Common questions

Could a blood test detect Parkinson's disease early?

This review identifies 5 neuropeptides that can be measured in blood, saliva, tears, or urine and show different levels in PD patients. While no single test is ready yet, combining multiple neuropeptide measurements could potentially detect PD years before motor symptoms appear.

Why is early PD detection important?

By the time Parkinson's motor symptoms (tremor, rigidity) appear, 50-80% of dopamine-producing neurons are already lost. Detecting the disease earlier—through neuropeptide biomarkers—could enable treatment before irreversible brain damage occurs, potentially changing the disease's trajectory.

Read the original research

Deciphering the role of neuropeptides as biomarkers for early diagnosis of Parkinson's disease.

Life sciences, 363, 123376

View on PubMed ↗Publisher’s paper ↗

Citation

Thakur, Jhanvi; Godad, Angel. (2025). Deciphering the role of neuropeptides as biomarkers for early diagnosis of Parkinson's disease.. Life sciences, 363, 123376. https://doi.org/10.1016/j.lfs.2025.123376