MicroRNAs are reportedly involved in the pathogenesis of
neurodegenerative diseases, including
Parkinson's disease and
multiple system atrophy. We previously identified 7 differentially expressed
microRNAs in
Parkinson's disease patients and control sera (miR-30c, miR-31, miR-141, miR-146b-5p, miR-181c, miR-214, and miR-193a-3p). To investigate the expression levels of the 7 serum
microRNAs in
Parkinson's disease and
multiple system atrophy, 23 early
Parkinson's disease patients (who did not take any anti-
Parkinson's disease drugs), 23
multiple system atrophy patients, and 24 normal controls were recruited at outpatient visits in this study. The expression levels of the 7
microRNAs in serum were detected using quantitative real-time polymerase chain reaction. A receiver operating characteristic curve was used to evaluate whether
microRNAs can differentially diagnose
Parkinson's disease and
multiple system atrophy. Clinical scales were used to analyze the correlations between serum
microRNAs and clinical features. The results indicated that miR-214 could distinguish
Parkinson's disease from the controls, and another 3
microRNAs could differentiate
multiple system atrophy from the controls (miR-141, miR-193a-3p, and miR-30c). The expression of miR-31, miR-141, miR-181c, miR-193a-3p, and miR-214 were lower in
multiple system atrophy than in
Parkinson's disease (all P < 0.05). Combinations of
microRNAs accurately discriminated
Parkinson's disease from
multiple system atrophy (area under the receiver operating characteristic curve = 0.951). For the correlation analysis, negative correlations were discovered between the expression of miR-214 and the Hamilton Anxiety Scale and
Parkinson's Disease Non-Motor Symptom scores (all P < 0.05). Our results demonstrate that the distinctive characteristics of
microRNAs differentiate
Parkinson's disease and
multiple system atrophy patients from healthy controls and may be used for the early diagnosis of
Parkinson's disease and
multiple system atrophy.