Affiliations: [a] Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China | [b] Clinical Research Unit, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
Correspondence:
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Correspondence to: Xiaodong Yang, MD, PhD, Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin Er Road, Shanghai 200025, P.R. China. Tel.: +86 18521725657; Fax: +86 21 6445 4473; E-mail: [email protected] and Qin Xiao, MD, PhD, Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin Er Road, Shanghai 200025, P.R. China. Tel.: +86 15921216530; Fax: +86 21 6445 4473; E-mail: [email protected].
Note: [1] These authors contributed equally to this work.
Abstract: Background:Multiple system atrophy (MSA) and Parkinson’s disease (PD) have overlapping symptoms, making diagnosis challenging. Short-chain fatty acids (SCFAs) are produced exclusively by gut microbiota and were reduced in feces of MSA patients. However, plasma SCFA concentrations in MSA patients have not been investigated. Objective:We aimed to investigate the plasma SCFAs in MSA patients and to identify the potential differential diagnostic ability. Methods:Plasma SCFA were measured in 25 MSA patients, 46 healthy controls, and 46 PD patients using gas chromatography-mass spectrometry. Demographic and clinical characteristics of the participants were evaluated. Results:Acetic acid concentration was lower in MSA patients than in healthy controls. Acetic acid and propionic acid concentrations were lower in MSA and MSA with predominant parkinsonism (MSA-P) patients than in PD patients. A receiver operating characteristic curve (ROC) analysis revealed reduced acetic acid concentration discriminated MSA patients from healthy controls with 76% specificity but only 57% sensitivity and an area under the curve (AUC) of 0.68 (95% confidence interval (CI): 0.55–0.81). Combined acetic acid and propionic acid concentrations discriminated MSA patients from PD patients with an AUC of 0.82 (95% CI: 0.71–0.93), 84% specificity and 76% sensitivity. Especially, with combined acetic acid and propionic acid concentrations, MSA-P patients were separated from PD patients with an AUC of 0.89 (95% CI: 0.80–0.97), 91% specificity and 80% sensitivity. Conclusion:Plasma SCFAs were decreased in MSA patients. The combined acetic acid and propionic acid concentrations may be a potential biomarker for differentiating MSA patients from PD patients.
Keywords: Multiple system atrophy, Parkinson’s disease, short-chain fatty acids, biomarker
