Study Looks at Biomarker for Parkinson Disease

A study aiming to determine whether blood cells expressing α‐synuclein (α‐syn) can differentiate Parkinson disease (PD) from healthy controls (HC), finding that there is potential usefulness of blood cells expressing α‐syn as a biomarker for PD.

The research, published in Annals of Clinical and Translational Neurology, identified concentrations of α‐syn in samples of blood cell pellets using a quantitative Lipid-ELISA assay. Protein, hemoglobin, iron, and H-ferritin levels were also measured.

“The accessibility of the blood makes it a favorable sampling bio-fluid that can assist the follow-up and treatment of a patient during the course of the disease. a-Syn in blood has been tested as a biomarker for PD. However, it is important to emphasize the biology of a-Syn in the blood and the potential relevance to the disease. A principal source for a-Syn detected in blood is blood cells expressed α -Syn, particularly of erythroid lineage,” explained the authors.

The samples were taken from the BioFIND cohort, consisting of 46 patients with PD and 45 HC. The results were then validated with another cohort, involving 35 patients with PD and 28 HC.

According to the researchers, a composite biomarker consisting of the concentrations of total a-syn, proteinase-K resistant (PKres) α-syn and phospho-Serine 129 α-syn (PSer 129) was designed using the BioFIND cohort. The biomarker differentiated a PD subgroup—presenting motor symptoms without dementia—from a HC group with significant accuracy. The validation cohort demonstrated similar results.

“Tracking longitudinally the dynamics of the composite biomarker with progression of Parkinson’s disease is critical for its evaluation as a reliable biomarker that reflects on severity of disease. Previous studies have shown that α-Syn levels, determined in CSF or blood plasma, differentiated between early PD and control groups,” concluded the authors. “A longitudinal study that will determine whether alterations in blood cell-expressed α-Syn forms are associated with disease progression is required.”

Reference

Elhadi S, Grigoletto J, Poli M, et al. α‐Synuclein in blood cells differentiates Parkinson’s disease from healthy controls [published online November 19, 2019]. Ann Clin Transl Neurol. doi.org/10.1002/acn3.50944