Decreased soluble Nogo-B in serum as a promising biomarker for Parkinson's disease

Background: Recently, the neurite outgrowth inhibitor-B (Nogo-B) receptor has been reported as a novel candidate gene for Parkinson's disease (PD). Nogo-B receptors need to combine with soluble Nogo-B to exert their physiological function. However, little is known about the relationship between serum soluble Nogo-B and PD.Methods: Serum levels of sNogo-B and alpha-Synuclein (alpha-Syn) were measured in a cohort of 53 patients with PD and 49 healthy controls with the ELISA kit method.Results: Serum sNogo-B level is significantly lower in the PD group than that in healthy controls and is negatively correlated with UPDRS-III score (p = 0.049), H & Y stage (p = 0.0108) as well as serum alpha-Syn level (p = 0.0001). The area under the curve (AUC) of serum sNogo-B in differentiating patients with PD from controls was 0.801 while the AUC of serum alpha-Syn was 0.93. Combining serum sNogo-B and alpha-Syn in differentiating patients with PD from HC presented higher discriminatory potential (AUC = 0.9534).Conclusion: Decreased serum sNogo-B may be a potential biomarker for PD. Lower Nogo-B level reflects worse motor function and disease progression of PD. Serum sNogo-B is of added value to serum alpha-Syn panel in distinguishing PD from controls. Future studies are needed to confirm in larger samples and different populations.