Downregulation of serum miR-106b: a potential biomarker for Alzheimer disease.

Analysis of miRNAs has a strong potential for the identification of novel prognostic or predictive biomarkers in the serum of AD patients. In this study, we investigated the serum levels of miR-106b as a diagnostic biomarker for AD and evaluate its predictive value for therapeutic response to the drug rivastigmine. Patients were divided into either responding ( n  = 33) or non-responding ( n  = 23) groups according to rivastigmine treatment and to Mini-Mental State Exam score. The serum concentrations of miR-106b were measured with real-time PCR. Here, we found that miR-106b was significantly down-regulated in the serum samples of AD patients compared with those of controls ( p  < .001). ROC results showed a specificity of 62% and a sensitivity of 94%. The serum values of miR-106b tended to be positively associated with the therapeutic response but were not significant ( p  = .15). Taken together, detection of serum miR-106b might be a promising serum biomarker for early diagnosis of AD.