[This corrects the article DOI: 10.3389/fneur.2025.1578252.].

• Publication type
• Published Erratum MeSH

Although it has been more than 200 years since Parkinson's disease was described, we have not established biomarkers for its definitive diagnosis yet. Moreover, there is a similar case for the entire group of α-synucleinopathies, which are all characterized by the pathological accumulation of aggregated α-synuclein (α-Syn) in the brain and other tissues. In different biological materials (blood, cerebrospinal fluid, saliva, or skin), α-Syn exists in various conformations and various aggregated states depending on the surrounding environment. Lewy bodies have been considered a pathognomonic feature of Parkinson's disease for over 100 years, and α-Syn has been known to be a key component of Lewy bodies for over 25 years, making it possible to confirm the diagnosis by post-mortem examination of brain tissue. To overcome these limitations, novel analytical seed amplification assays (SAAs) were introduced, and they quickly became one of the most effective diagnostic tools for antemortem detection of α-synucleinopathies. As they require minimal sample amounts to provide consistent, rapid, and reliable results, SAAs are ideally suited for biomarker determination. This review examines SAA analytical and detection methods, their advantages and strengths, as well as their limitations and shortcomings that need to be addressed to establish a reliable and reproducible protocol. This could serve as a diagnostic methodology worldwide to determine the presence of pathological α-Syn protein at early stages and help develop effective disease-modifying treatment.

• Publication type
• Journal Article MeSH
• Review MeSH

Real-time quaking-induced conversion assay (RT-QuIC) exploits templating activity of pathogenic prion protein for ultrasensitive detection of prions. We have utilized second generation RT-QuIC assay to analyze matching post-mortem cerebrospinal fluid and skin samples of 38 prion disease patients and of 30 deceased neurological controls. The analysis of cerebrospinal fluid samples led to 100% sensitivity and 100% specificity, but some samples had to be diluted before the analysis to alleviate the effect of present RT-QuIC inhibitors. The analysis of the corresponding skin samples provided 89.5% sensitivity and 100% specificity. The median seeding dose present in the skin was one order of magnitude higher than in the cerebrospinal fluid, despite the overall fluorescent signal of the skin samples was comparatively lower. Our data support the use of post-mortem cerebrospinal fluid for confirmation of prion disease diagnosis and encourage further studies of the potential of skin biopsy samples for intra-vitam prion diseases ́ diagnostics.

• MeSH
• Biological Assay MeSH
• Creutzfeldt-Jakob Syndrome * diagnosis   cerebrospinal fluid   MeSH
• Skin metabolism   MeSH
• Humans MeSH
• Prion Proteins MeSH
• Prion Diseases * diagnosis   MeSH
• Prions * metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Diagnostika prionových onemocnění je obtížná vzhledem k jejich heterogenitě a překryvu klinických příznaků s jinými neurodegenerativními chorobami. Doposud dostupné diagnostické metody neměly dostatečnou citlivost a specificitu. V roce 2018 byla do diagnostických kritérií (WHO) zařazena metoda RT­‐QuIC (Real Time Quacking Induced Conformation assay), která využívá pro detekci prionů jejich schopnost agregovat nativní rekombinantní prionový protein. Agregace je sledována v reálném čase pomocí fluorescenční sondy. Metoda je extrémně citlivá a specifická. Naše výsledky potvrzují, že umožňuje detekci prionů v mozkomíšním moku pacientů za jejich života, krátce po objevení příznaků onemocnění.

Diagnostics of prion diseases is difficult due to their heterogeneity and overlap of clinical symptoms with other neurodegenerative disorders. Till now utilized diagnostics methods did not have sufficient sensitivity and specificity. In 2018 WHO diagnostic criteria were updated by the inclusion of RT-QuIC assay (Real Time Quacking Induced Conformation), which utilizes the ability of prions to aggregate native recombinant prion protein for their detection. The aggregation is monitored in real time using fluorescent probe. The assay is extremely sensitive and specific. Our results confirms that it allows detection of prions in cerebrospinal fluid of living patients shortly after the appearance of symptoms.

• MeSH
• Creutzfeldt-Jakob Syndrome diagnosis   MeSH
• Diagnosis, Differential MeSH
• Clinical Laboratory Techniques methods   MeSH
• Humans MeSH
• Prion Diseases * diagnosis   MeSH
• Prions analysis   cerebrospinal fluid   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

Prionové choroby jsou smrtelná neurodegenerativní onemocnění spojená s hromaděním agregovaného konformačně pozměněného prionového proteinu v mozku postižených jedinců. Onemocnění je přenosné, neexistuje účinná léčba a v současnosti lze jeho diagnózu potvrdit pouze neuropatologickým vyšetřením post mortem. Náš projekt je zaměřen na využití nové revoluční metody RT-QuIC (Real-Time Quaking Induced Conversion) pro potvrzení diagnózy onemocnění za života pacienta. Metoda RT-QuIC již prokázala vysokou specificitu a senzitivitu při analýze mozkomíšního moku, která tento rok vedla k jejímu zahrnutí do mezinárodních diagnostických kritérií Cretzfeldtovy-Jakobovy nemoci. Náš projekt specificky cílí na posouzení diagnostického potenciálu RT-QuIC u snadno dostupných vzorků moči a kůže. Důležitost rychlého potvrzení diagnózy pomocí minimálně invazivního postupu tkví nejen v prevenci rizika nozokomiálního přenosu prionů a včasné aplikaci specializované péče o pacienta, ale i ve vytvoření nezbytného prostoru pro vyvíjené terapeutické zásahy v budoucnosti.; Prion diseases are fatal neurodegenerative disorders connected with accumulation of aggregated misfolded prion protein in the brain of affected individuals. The diseases are transmissible, no therapy is available and at present the diagnosis is confirmed only after neuropathological assessment post mortem. Our project is aimed on utilization of a new revolutionary method, Real-Time Quaking Induced Conversion (RT-QuIC) assay, for intravital diagnostics of prion diseases. The method already showed superior sensitivity and specificity in analysis of cerebrospinal fluid which led to its recent inclusion into internationally recognized diagnostic criteria for Creutzfeldt-Jakob disease. Our project specifically aims to assess diagnostic potential of RT-QuIC in analysis of easily accessible samples of urine and skin. The importance of early diagnosis confirmation using minimally invasive procedure lays in mitigation of the risk of prion nosocomial transmission, in immediate implementation of special patient care and in securing a room for therapeutic intervention in the future.

• Keywords
• RT-QuIC,
• MeSH
• Creutzfeldt-Jakob Syndrome diagnosis   MeSH
• Clinical Chemistry Tests methods   MeSH
• Skin chemistry   MeSH
• Urine chemistry   MeSH
• Cerebrospinal Fluid chemistry   MeSH
• Prion Proteins chemistry   MeSH
• Prion Diseases diagnosis   MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• neurologie
• NML Publication type
• závěrečné zprávy o řešení grantu AZV MZ ČR

Rada neurodegeneratívnych ochorení je definovaná agregáciou a akumuláciou špecifického patologického proteínu v CNS, čo vedie k nezvratným a fatálnym zmenám tkaniva. Avšak kvôli vysokej klinickej a epidemiologickej heterogenite je definitívna ante-mortem diagnostika týchto ochorení obtiažna. Definitívne potvrdenie diagnózy poskytuje až neuropatologické vyšetrenie mozgového tkaniva. Nádej pre skorú a presnú laboratórnu diagnostiku týchto ochorení za života pacienta predstavujú metódy založené na detekcii konformáciu konvertujúcej aktivity patologických proteínov. Príkladom je nová, vysoko špecifická a senzitívna diagnostická metóda Real-Time Quaking-Induced Conversion (RT-QuIC). Pôvodne bola vyvinutá na diagnostiku priónových ochorení vykazujúc 92–97 % senzitivitu a 100 % špecificitu. V našom laboratóriu sme pomocou RT-QuIC detegovali prióny v 39 vzorkách mozgu, 24 korešpondujúcich vzorkách moku a v 38 vzorkách kože pacientov s Creutzfeldt-Jakobovou chorobou. Najnovšie bolo opísané využitie RT-QuIC metódy na detegovanie patologických proteínov a-synukleínu, ktorý sa hromadí pri Parkinsonovej chorobe alebo pri demencii s Lewyho telieskami a tau proteínu, charakteristického pre Alzheimerovu chorobu a kortikobazálnu degeneráciu. Predložený text sa zameriava na oboznámenie problematiky diagnostiky neurodegeneratívnych ochorení pomocou RT-QuIC metódy.

Many neurodegenerative diseases are defined by the aggregation and accumulation of the specific pathological protein in the CNS, leading to irreversible and fatal changes of the tissues. However, due to high clinical and epidemiological heterogeneity, a definitive ante-mortem diagnosis is very difficult to perform. The definitive diagnosis is confirmed by neuropathological evaluation made only at autopsy. Hope for early and accurate laboratory diagnostics of these diseases within a patient’s life represents methods based on the detection of seeding activity of pathological proteins. An example is a highly specific and ultrasensitive new method called Real-Time Quaking-Induced Conversion (RT-QuIC) assay. Originally, RT-QuIC was developed for the diagnosis of prions showing 92–97% sensitivity and 100% specificity. In our laboratory, we were able to detect prions in 39 brain samples, corresponding 24 cerebrospinal fluid samples, and in 38 skin samples of patients with Creutzfeldt-Jakob disease using RT-QuIC. Lately, the use of the RT-QuIC method for detection of pathological protein a-synuclein, which accumulates during Parkinson’s disease or dementia with Lewy bodies, and tau protein which is characteristic for Alzheimer’s disease or corticobasal degeneration, was described. This review aims to elucidate the diagnosis of neurodegenerative diseases and its recent approaches using RT-QuIC.

• Keywords
• RT-QuIC,
• MeSH
• Alzheimer Disease diagnosis   MeSH
• Humans MeSH
• Neurodegenerative Diseases * diagnosis   MeSH
• Parkinson Disease diagnosis   MeSH
• Prion Proteins analysis   MeSH
• Prion Diseases diagnosis   MeSH
• Prions analysis   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

The possibilities for diagnosing prion diseases have shifted significantly over the last 10 years. The RT-QuIC assay option has been added for neuropsychiatric symptoms, supporting biomarkers and final post-mortem confirmation. Samples of brain homogenates used for final diagnosis, archived for many years, provide the possibility for retrospective studies. We used a second-generation RT-QuIC assay to detect seeding activity in different types of sporadic and genetic prion diseases in archival brain homogenates and post-mortem CSF samples that were 2 to 15 years old. Together, we tested 92 archival brain homogenates: 39 with definite prion disease, 28 with definite other neurological disease, and 25 with no signs of neurological disorders. The sensitivity and specificity of the assay were 97.4% and 100%, respectively. Differences were observed in gCJD E200K, compared to the sporadic CJD group. In 52 post-mortem CSF samples-24 with definite prion disease and 28 controls-we detected the inhibition of seeding reaction due to high protein content. Diluting the samples eliminated such inhibition and led to 95.8% sensitivity and 100% specificity of the assay. In conclusion, we proved the reliability of archived brain homogenates and post-mortem CSF samples for retrospective analysis by RT-QuIC after long-term storage, without changed reactivity.

• Publication type
• Journal Article MeSH