Meta-microRNAs as potential noninvasive markers for early diagnosis of Alzheimer's disease

Introduction: The aim of this study was to investigate the potential role of a microRNA panel as early diagnostic markers for Alzheimer9s disease (AD). Methods: The differentially expressed serum microRNAs were screened with microarray among cognitively normal controls (CNC), mild cognitive impairment (MCI), and AD. QRT-PCR assay was applied to evaluate differentially expressed microRNAs with two independent cohorts including 202 participants. Logistic regression model based on microRNA panel was constructed using a training cohort and then validated using an independent cohort. Results: First, four differentially expressed serum microRNAs (let-7g, miR-197, miR-126 and miR-29a) were found, which expressions were positively correlated with mini mental state examination (MMSE) score. Second, a microRNA panel with the four microRNAs demonstrated good diagnostic performance for MCI and AD with 84% and 92% accuracy. Third, when combined with MMSE score, the diagnostic performance of the microRNA panel was further improved. Discussion: Blood microRNAs are potential AD biomarkers that may lead to new diagnostic strategies.Keywords: Alzheimer9s disease/ microRNA/ early diagnosis