TY  - JOUR
A1  - Kuzkina, Anastasia
A1  - Bargar, Connor
A1  - Schmitt, Daniela
A1  - Rößle, Jonas
A1  - Wang, Wen
A1  - Schubert, Anna-Lena
A1  - Tatsuoka, Curtis
A1  - Gunzler, Steven A.
A1  - Zou, Wen-Quan
A1  - Volkmann, Jens
A1  - Sommer, Claudia
A1  - Doppler, Kathrin
A1  - Chen, Shu G.
T1  - Diagnostic value of skin RT-QuIC in Parkinson's disease: a two-laboratory study
JF  - NPJ Parkinson's Disease
N2  - Skin alpha-synuclein deposition is considered a potential biomarker for Parkinson's disease (PD). Real-time quaking-induced conversion (RT-QuIC) is a novel, ultrasensitive, and efficient seeding assay that enables the detection of minute amounts of alpha-synuclein aggregates. We aimed to determine the diagnostic accuracy, reliability, and reproducibility of alpha-synuclein RT-QuIC assay of skin biopsy for diagnosing PD and to explore its correlation with clinical markers of PD in a two-center inter-laboratory comparison study. Patients with clinically diagnosed PD (n = 34), as well as control subjects (n = 30), underwent skin punch biopsy at multiple sites (neck, lower back, thigh, and lower leg). The skin biopsy samples (198 in total) were divided in half to be analyzed by RT-QuIC assay in two independent laboratories. The a-synuclein RT-QuIC assay of multiple skin biopsies supported the clinical diagnosis of PD with a diagnostic accuracy of 88.9% and showed a high degree of inter-rater agreement between the two laboratories (92.2%). Higher alpha-synuclein seeding activity in RT-QuIC was shown in patients with longer disease duration and more advanced disease stage and correlated with the presence of REM sleep behavior disorder, cognitive impairment, and constipation. The alpha-synuclein RT-QuIC assay of minimally invasive skin punch biopsy is a reliable and reproducible biomarker for Parkinson's disease. Moreover, alpha-synuclein RT-QuIC seeding activity in the skin may serve as a potential indicator of progression as it correlates with the disease stage and certain non-motor symptoms.
KW  - diagnostic markers
KW  - Parkinson's disease
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260451
VL  - 7
IS  - 1
ER  - 
TY  - JOUR
A1  - Brumberg, Joachim
A1  - Kuzkina, Anastasia
A1  - Lapa, Constantin
A1  - Mammadova, Sona
A1  - Buck, Andreas
A1  - Volkmann, Jens
A1  - Sommer, Claudia
A1  - Isaias, Ioannis U.
A1  - Doppler, Kathrin
T1  - Dermal and cardiac autonomic fiber involvement in Parkinson's disease and multiple system atrophy
JF  - Neurobiology of Disease
N2  - Pathological aggregates of alpha-synuclein in peripheral dermal nerve fibers can be detected in patients with idiopathic Parkinson's disease and multiple system atrophy. This study combines skin biopsy staining for p-alpha-synuclein depositions and radionuclide imaging of the heart with [\(^{123}\)I]-metaiodobenzylguanidine to explore peripheral denervation in both diseases. To this purpose, 42 patients with a clinical diagnosis of Parkinson's disease or multiple system atrophy were enrolled. All patients underwent a standardized clinical workup including neurological evaluation, neurography, and blood samples. Skin biopsies were obtained from the distal and proximal leg, back, and neck for immunofluorescence double labeling with anti-p-alpha-synuclein and anti-PGP9.5. All patients underwent myocardial [\(^{123}\)I]-metaiodobenzylguanidine scintigraphy. Dermal p-alpha-synuclein was observed in 47.6% of Parkinson's disease patients and was mainly found in autonomic structures. 81.0% of multiple system atrophy patients had deposits with most of cases in somatosensory fibers. The [\(^{123}\)I]-metaiodobenzylguanidine heart-to-mediastinum ratio was lower in Parkinson's disease than in multiple system atrophy patients (1.94 +/- 0.63 vs. 2.91 +/- 0.96; p < 0.0001). Irrespective of the diagnosis, uptake was lower in patients with than without p-alpha-synuclein in autonomic structures (1.42 +/- 0.51 vs. 2.74 +/- 0.83; p < 0.0001). Rare cases of Parkinson's disease with p-alpha-synuclein in somatosensory fibers and multiple system atrophy patients with deposits in autonomic structures or both fiber types presented with clinically overlapping features. In conclusion, this study suggests that alpha-synuclein contributes to peripheral neurodegeneration and mediates the impairment of cardiac sympathetic neurons in patients with synucleinopathies. Furthermore, it indicates that Parkinson's disease and multiple system atrophy share pathophysiologic mechanisms of peripheral nervous system dysfunction with a clinical overlap.
KW  - peripheral nervous system
KW  - Parkinson's disease
KW  - skin biopsy
KW  - MIBG scintigraphy
KW  - multiple system atrophy
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260061
VL  - 153
ER  -