Validation and Application of Skin RT-QuIC to Patients in China with Probable CJD.

Kang Xiao,Qi Shi,Xuehua Yang,Wei Zhou,Xiaoping Dong,Cao Chen

doi:10.3390/pathogens10121642

Abstract

The definite diagnosis of human sporadic Creutzfeldt–Jakob disease (sCJD) largely depends on postmortem neuropathology and PrPSc detection in the brain. The development of real-time quaking-induced conversion (RT-QuIC) of cerebrospinal fluid (CSF) samples makes it possible for premortem diagnosis for sCJD. To test the diagnostic potential of RT-QuIC of skin specimens for probable sCJD, we collected the paired skin and CSF samples from 51 recruited living patients referred to the Chinese CJD surveillance center, including 34 probable sCJD, 14 non-CJD, and 3 genetic prion disease (gPrD). The samples were subjected to RT-QuIC assays using recombinant hamster PrP protein rHaPrP90-231 as the substrate. Using skin RT-QuIC assay, 91.2% (31/34) probable sCJD patients, and 1 T188K genetic CJD (gCJD) cases showed positive prion-seeding activity, while 85.7% (12/14) non-CJD patients were negative. CSF RT-QuIC positive seeding activity was only observed in 14 probable sCJD patients. Analysis of the reactivity of 38 positive skin RT-QuIC tests revealed that the positive rates in the preparations of 10−2, 10−3 and 10−4 diluted skin samples were 88.6% (39/44), 63.6% (28/44), and 25.0% (11/44), respectively. Eleven probable sCJD patients donated two skin specimens collected at different sites simultaneously. Although 95.5% (21/22) skin RT-QuIC elicited positive reaction, the reactivity varied. Our preliminary data indicate high sensitivity and specificity of skin RT-QuIC in prion detection for Chinese probable sCJD and highlight that skin prion-seeding activity is a reliable biomarker for premortem diagnosis of human prion disease.

Highlights

Introduction published maps and institutional affilHuman prion disease (PrD) is a group of transmissible neurodegenerative diseases, consisting of sporadic form, e.g., sporadic Creutzfeldt–Jakob disease, genetic or familial form, e.g., genetic CJD, fatal familial insomnia (FFI), Gerstmann–Sträussler–Scheinker disease (GSS), and acquired form, e.g., iatrogenic CJD and variant CJD [1,2,3]. sCJD is the most common form of human PrD with the incidence of one to two patients per million per year
The skin samples of the coded 10 definite sCJD patients and 5 non-CJD controls from National Prion Disease Pathology Surveillance Center (NPDPSC) with a dilution from 10−2 to 10−4 were examined blindly by our real-time quaking-induced conversion (RT-QuIC) assay
cerebrospinal fluid (CSF) RT-QuIC assay is becoming an ideal method for the premortem diagnosis of sCJD and prion research based on its reliable specificity and high sensitivity [5,8]

Summary

Introduction

Introduction published maps and institutional affilHuman prion disease (PrD) is a group of transmissible neurodegenerative diseases, consisting of sporadic form, e.g., sporadic Creutzfeldt–Jakob disease (sCJD), genetic or familial form, e.g., genetic CJD (gCJD), fatal familial insomnia (FFI), Gerstmann–Sträussler–Scheinker disease (GSS), and acquired form, e.g., iatrogenic CJD (iCJD) and variant CJD (vCJD) [1,2,3]. sCJD is the most common form of human PrD with the incidence of one to two patients per million per year. Human prion disease (PrD) is a group of transmissible neurodegenerative diseases, consisting of sporadic form, e.g., sporadic Creutzfeldt–Jakob disease (sCJD), genetic or familial form, e.g., genetic CJD (gCJD), fatal familial insomnia (FFI), Gerstmann–Sträussler–. Scheinker disease (GSS), and acquired form, e.g., iatrogenic CJD (iCJD) and variant CJD (vCJD) [1,2,3]. SCJD is the most common form of human PrD with the incidence of one to two patients per million per year. The definite diagnosis of human PrD, for sCJD, is still largely dependent on postmortem brain tissues showing special neuropathological changes, i.e., spongiform degeneration, and/or PrPSc deposit [2], some biomarkers in cerebrospinal fluid (CSF) have revealed significances in diagnosis of sCJD, such as 14-3-3 and tau [4].

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Conclusion