Objective: To evaluate the utility of the real-time quaking-induced conversion (RT-QuIC) assay in stomach biopsies as a biomarker for early Parkinson’s disease (PD) and to investigate its association with various clinical characteristics.
Background: Studies have shown that alpha-synuclein (AS) accumulation is more frequently detected in the stomach than in the colon or rectum of patients with PD, suggesting its potential utility as a biomarker. However, few studies have used RT-QuIC assays to detect pathological AS-seeding activity in the stomach.
Method: This prospective study included 22 patients with early PD (disease duration: 2.1±1.1 years) and 17 healthy controls. All participants underwent gastric endoscopic biopsy, along with a comprehensive assessment of motor and non-motor symptoms at the time of biopsy. The RT-QuIC assay was performed to detect pathological AS-seeding activity. Clinical characteristics and symptoms were compared between patients with positive RT-QuIC results and those with negative results.
Results: Pathological AS-seeding activity was detected in 45.5% of patients with PD and 0% of controls (p=0.001). There were no significant differences in demographics, PD subtypes (including motor symptom laterality or tremor-dominant vs. akinetic-rigid), or clinical characteristics such as Unified Parkinson’s Disease Rating Scale scores, Hoehn and Yahr stage, cognitive function, depression scores, non-motor symptom burden, hyposmia, orthostatic hypotension, or rapid eye movement sleep behavior disorder symptoms, between the patients with positive RT-QuIC results (n=10) and those with negative results (n=12).
Conclusion: The AS RT-QuIC assay using stomach biopsies demonstrated a moderate positivity rate in patients with early PD and was not associated with clinical characteristics.
To cite this abstract in AMA style:
C. Shin, JP. Im, JY. Han, B. Jin, KA. Woo, S. Lee, HY. Jeon, JY. Joo, HJ. Chang, JH. Shin, HJ. Kim, JM. Kim, YP. Choi, B. Jeon. Diagnostic accuracy and clinical correlates of real-time quaking-induced conversion assay on gastric biopsy in early Parkinson’s disease [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/diagnostic-accuracy-and-clinical-correlates-of-real-time-quaking-induced-conversion-assay-on-gastric-biopsy-in-early-parkinsons-disease/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/diagnostic-accuracy-and-clinical-correlates-of-real-time-quaking-induced-conversion-assay-on-gastric-biopsy-in-early-parkinsons-disease/