Serum soluble lymphocyte activation gene-3 as a diagnostic biomarker in Parkinson's disease: A pilot multicenter study.

<bold>Objective: </bold>Lymphocyte activation gene-3 (LAG-3) could mediate pathological α-synuclein transmission in neurodegeneration and may be involved in the pathogenesis of Parkinson's disease (PD). The aim of the present study was to explore soluble LAG-3 (sLAG-3) as a potential diagnostic biomarker for PD.<bold>Methods: </bold>Serum sLAG-3 concentrations were measured by a quantitative ELISA for patients with PD, essential tremor (ET) and age- and sex-matched controls. The relationships between sLAG-3 and clinical phenotype were assessed via correlation analysis and logistic regression.<bold>Results: </bold>Serum sLAG-3 levels in patients with PD were significantly higher than those in ET patients and age- and sex-matched controls. The area under the curve of serum sLAG-3 in differentiating PD from age- and sex-matched controls was 0.82. Serum sLAG-3 was associated with non-motor symptoms and excessive daytime sleep.<bold>Conclusion: </bold>sLAG-3 is a candidate novel biomarker for PD. © 2018 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]