Diagnostic Accuracy and Predictors of Alpha-Synuclein Accumulation in Gastrointestinal Tract of Parkinson’s disease

Abstract

Abstract Background and objectives This study aimed to determine the possibility as a biomarker and identify predictors of alpha-synuclein (AS) accumulation in the gastrointestinal (GI) tract of patients with Parkinson’s disease (PD). Methods The frequency of AS accumulation in the GI tract was compared between patients with PD (N = 97) who underwent radical GI surgery for cancer and individually matched controls (N = 94). Clinical characteristics were compared between patients with positive (AS+) and negative (AS−) AS accumulation. A multivariable logistic regression analysis was conducted to determine the predictors of AS accumulation in the GI tract of patients with PD. Results The frequency of AS accumulation was significantly higher in patients with PD (75.3%) than in controls (8.5%, p-value < 0.001). However, when the evaluation was confined to the mucosal/submucosal layer, the sensitivity and specificity were 46.9% and 94.7%, respectively. The rostrocaudal gradient of AS accumulation was found in patients with PD. The duration from symptom onset to surgery was significantly longer in patients with PD and AS+ (4.9 ± 4.9 years) than in AS– (1.8 ± 4.1 years, p-value = 0.005). Both disease duration and surgical site independently predicted the presence of AS accumulation in the GI tract of patients with PD. Conclusions The results suggest that the stomach is the optimal location for identifying pathological biomarkers using AS accumulation in the GI tract. Our study suggests PD-related AS accumulation in the GI tract follows temporally increasing but spatially static progression pattern.