散发性Creutzfeldt-Jakob病(sCJD)的明确诊断依赖于对脑组织的病理性朊病毒蛋白(PrPSc)的检查。我们先前的研究表明,通过超灵敏的PrPSc种子扩增试验(PrPSc-SAA),可以在sCJD患者的皮肤中检测到PrPSc播种活性(PrPSc-SA),该试验被称为实时震颤诱导转化(RT-QuIC)。在尸检时,从2个队列(1和2个)中收集了875个皮肤样本,这些样本来自339例经神经病理证实的朊病毒病和非sCJD对照的2-3个身体区域。通过RT-QuIC测定法分析皮肤样品的PrPSc-SA。将结果与人口统计信息进行比较,临床表现,脑脊液(CSF)PrPSc-SA,其他实验室检查,由PrP残基129处的蛋氨酸(M)或缬氨酸(V)多态性定义的朊病毒疾病的亚型,PrPSc类型(#1或#2),以及死亡患者的基因突变.由两个独立实验室对队列#1进行的RT-QuIC分析给出了87.3%或91.3%的灵敏度和94.7%或100%的特异性,分别。队列#2显示89.4%的灵敏度和95.5%的特异性。从212例病例中获得的CSFRT-QuIC的敏感性为89.7%,特异性为94.1%。皮肤RT-QuIC的敏感性呈亚型依赖性,在sCJDVV1-2亚型中最高,其次是VV2、MV1-2、MV1、MV2、MM1、MM1-2、MM2和VV1。耳朵旁边的皮肤区域敏感度最高,其次是下背部和头部的顶点。尽管在假阴性和真阳性皮肤RT-QuIC结果的病例之间没有检测到大脑PrPSc-SA的差异,病程明显延长,假阴性[12.0±13.3(月,SD)与6.5±6.4,p<0.001]。我们的研究验证了皮肤PrPSc-SA作为检测朊病毒疾病的生物标志物,受PrPSc类型的影响,PRNP129多态性,皮刀取样,和疾病持续时间。
Definitive diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) relies on the examination of brain tissues for the pathological
prion protein (PrPSc). Our previous study revealed that PrPSc-seeding activity (PrPSc-SA) is detectable in skin of sCJD patients by an ultrasensitive PrPSc seed amplification assay (PrPSc-SAA) known as real-time quaking-induced conversion (RT-QuIC). A total of 875 skin samples were collected from 2 cohorts (1 and 2) at autopsy from 2-3 body areas of 339 cases with neuropathologically confirmed
prion diseases and non-sCJD controls. The skin samples were analyzed for PrPSc-SA by RT-QuIC assay. The results were compared with demographic information, clinical manifestations, cerebrospinal fluid (CSF) PrPSc-SA, other laboratory tests, subtypes of
prion diseases defined by the methionine (M) or valine (V) polymorphism at residue 129 of PrP, PrPSc types (#1 or #2), and gene mutations in deceased patients. RT-QuIC assays of the cohort #1 by two independent laboratories gave 87.3% or 91.3% sensitivity and 94.7% or 100% specificity, respectively. The cohort #2 showed sensitivity of 89.4% and specificity of 95.5%. RT-QuIC of CSF available from 212 cases gave 89.7% sensitivity and 94.1% specificity. The sensitivity of skin RT-QuIC was subtype dependent, being highest in sCJDVV1-2 subtype, followed by VV2, MV1-2, MV1, MV2, MM1, MM1-2, MM2, and VV1. The skin area next to the ear gave highest sensitivity, followed by lower back and apex of the head. Although no difference in brain PrPSc-SA was detected between the cases with false negative and true positive skin RT-QuIC results, the disease duration was significantly longer with the false negatives [12.0 ± 13.3 (months, SD) vs. 6.5 ± 6.4, p < 0.001]. Our study validates skin PrPSc-SA as a biomarker for the detection of
prion diseases, which is influenced by the PrPSc types, PRNP 129 polymorphisms, dermatome sampled, and disease duration.