Abstract

INTRODUCTIONSeveral microRNAs (miRNAs) have been implicated in Alzheimers disease (AD) pathogenesis but the evidence from individual case-control-studies remains inconclusive.\n\nMETHODSA systematic literature review was performed, followed by standardised multi-stage data extraction, quality control, and meta-analyses on eligible data for brain, blood, and cerebrospinal fluid (CSF) specimens. Results were compared with miRNAs reported in the abstracts of eligible studies or recent qualitative reviews to assess novelty.\n\nRESULTSData from 147 independent datasets across 107 publications were quantitatively assessed in 461 meta-analyses. Twenty-five, five, and 32 miRNAs showed study-wide significant differential expression (<1.08x10-4) in brain, CSF, and blood-derived specimens, respectively, with 5 miRNAs showing differential expression in both brain and blood. Of these 57 miRNAs, 13 had not been reported in the abstracts of previous original or review articles.\n\nDISCUSSIONOur systematic assessment of differential miRNA expression is the first of its kind in AD and highlights miRNAs of relevance.