초록
Objective: In the present study, real-time quaking-induced conversion (RT-QuIC) assay was used to evaluate
pathologic alpha-synuclein (AS) seeding activity in formalin-fixed paraffin-embedded (FFPE) tissue from the
gastrointestinal (GI) tract of Parkinson’s disease (PD) patients.
Methods: This study was conducted in two parts: Part I. a preliminary autopsy study that included four autopsy-
confirmed patients with synucleinopathy (2 PD, 1 dementia with Lewy bodies [DLB], and 1 multiple system
atrophy [MSA]) and two normal autopsy controls. Frozen and FFPE tissues of the brain were obtained. Part II. a
clinical case-control study that included 20 clinically diagnosed PD patients and matched controls. Surgically
resected FFPE tissues from the upper and lower GI tracts were used. The RT-QuIC assay was performed to
evaluate pathologic seed amplification using frozen or FFPE tissues. The presence or absence of AS aggregation
was confirmed by conventional phosphorylated AS (pAS) immunohistochemistry (IHC).
Results: In Part I, RT-QuIC assay showed pathologic AS amplification in frozen and FFPE brain tissues of PD and
DLB patients, and FFPE stomach tissue of PD patients but not in the MSA patient and controls. In Part II,
pathologic seeding activity was found in 10% (2/20) of the stomach tissues of clinical PD patients but in none of
the matched controls. IHC showed pAS-positive staining in 55% of patients (11/20) and 15% of controls (3/20).
Conclusion: The present study results showed that the RT-QuIC assay using FFPE tissue of the GI tract was
inadequate as a biomarker in PD
pathologic alpha-synuclein (AS) seeding activity in formalin-fixed paraffin-embedded (FFPE) tissue from the
gastrointestinal (GI) tract of Parkinson’s disease (PD) patients.
Methods: This study was conducted in two parts: Part I. a preliminary autopsy study that included four autopsy-
confirmed patients with synucleinopathy (2 PD, 1 dementia with Lewy bodies [DLB], and 1 multiple system
atrophy [MSA]) and two normal autopsy controls. Frozen and FFPE tissues of the brain were obtained. Part II. a
clinical case-control study that included 20 clinically diagnosed PD patients and matched controls. Surgically
resected FFPE tissues from the upper and lower GI tracts were used. The RT-QuIC assay was performed to
evaluate pathologic seed amplification using frozen or FFPE tissues. The presence or absence of AS aggregation
was confirmed by conventional phosphorylated AS (pAS) immunohistochemistry (IHC).
Results: In Part I, RT-QuIC assay showed pathologic AS amplification in frozen and FFPE brain tissues of PD and
DLB patients, and FFPE stomach tissue of PD patients but not in the MSA patient and controls. In Part II,
pathologic seeding activity was found in 10% (2/20) of the stomach tissues of clinical PD patients but in none of
the matched controls. IHC showed pAS-positive staining in 55% of patients (11/20) and 15% of controls (3/20).
Conclusion: The present study results showed that the RT-QuIC assay using FFPE tissue of the GI tract was
inadequate as a biomarker in PD
