The feasibility of utilizing plasma MiRNA107 and BACE1 messenger RNA gene expression for clinical diagnosis of amnestic mild cognitive impairment

Objective: To investigate the relationship between microRNA107 (miRNA107) and BACE1 messenger RNA (mRNA) gene expressions in plasma and their diagnostic capability to distinguish subjects with amnestic mild cognitive impairment from healthy controls. Method: We recruited 97 patients with Alzheimer's disease according to diagnostic criteria of DSM-IV and National Institute of Neurologic and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association, 116 subjects with amnestic mild cognitive impairment, and 81 healthy controls from January 2012 to December 2012. The real-time PCR was used to quantify miRNA107 and BACE1 mRNA. The power of classification accuracies between patients with amnestic mild cognitive impairment and healthy controls was performed using linear discriminate analysis single or combining both the expression miRNA107 and BACE1 mRNA. Results: For patients with Alzheimer's disease, the miRNA107 expressions in plasma and cerebral spinal fluid were correlated (Pearson correlation = 0.665, P = .034). There were statistically significant correlations between plasma miRNA107 and BACE1 mRNA gene expression in Alzheimer's disease, amnestic mild cognitive impairment, and healthy control groups (r value = -0.316 [P = .002], -0.615 [P < .001], and -0.367 [P = .001], respectively). The overall classification accuracy of miRNA107 to discriminate between patients with amnestic mild cognitive impairment and healthy controls was 91.9%, with sensitivity of 98.3% and specificity of 82.7%. Conclusions: The miRNA107 expression in plasma has a high capability to discriminate between patients with amnestic mild cognitive impairment and healthy controls.