CSF alpha-Synuclein and Tau as Biomarkers for Dementia With Lewy Bodies A Systematic Review and Meta-analysis

Objective: This study investigated whether alpha-synuclein and tau in cerebrospinal fluid (CSF) can be used as biomarkers to diagnose dementia with Lewy bodies (DLB). Materials and Methods: We retrieved 3303 studies with "Dementia with Lewy bodies," "alpha-synuclein," and "tau" as keywords. We formulated screening criteria, and 2 researchers completed the screening, quality evaluation, and data extraction tasks. Finally, 35 studies related to tau, and 14 studies related to alpha-synuclein were included. Review Manager 5.4 and Stata16 were used for meta-analysis. Subgroup, sensitivity, and meta-regression analyses were performed to identify sources of heterogeneity and strengthen the results. Results: Compared with the control group, DLB patients showed significantly higher CSF levels of tau [weighted mean difference = 81.36 (59.82, 102.91); Z = 7.40; P < 0.00001], and lower CSF levels of alpha-synuclein [weighted mean difference = -95.25 (-162.02, -28.48); Z = 2.80; P = 0.005]. Mini-Mental State Examination (MMSE) score, male ratio, and disease duration were not sources of heterogeneity on subgroup and meta-regression analyses. Sensitivity analysis revealed no significant differences. Conclusions: Higher levels of tau and lower levels of alpha-synuclein were found in the CSF of patients with DLB compared with the control group. Therefore, CSF tau and alpha-synuclein levels may be diagnostic biomarkers for DLB.