The use of second generation RT‐QuIC assay for the diagnosis of Creutzfeldt Jakob disease patients in Brazil

Abstract

AbstractBackgroundThe recent development of IQ‐CSF, the second generation of Real Time Quaking‐Induced Conversion (RT‐QuIC) using cerebrospinal fluid (CSF), for the diagnosis of Creutzfeldt Jakob Disease (CJD) represents a major diagnostic advance in the field. High accuracy results have been reported with encouraging reproducibility among different centers. The aim of this research is to report the pilot use of IQ‐CSF in a small cohort of Brazilian patients with possible or probable CJD, implementing a reference center in the country.MethodWe stored CSF samples from patients with possible, probable or genetic CJD (one case) during the timeframe of December 2016 through June 2018. All CSF samples were processed according to standardized protocols without access to the clinical data. Eight patients presented to our team with a rapidly progressive dementia and typical neurological signs of CJD. We used CSF samples from 8 patients with other neurological conditions as controls.Result7 out of 9 suspected cases had positive tests; among controls, there was 1 false‐positive (a CSF sample from a 4‐year‐old child with leukemia under treatment). The occurrence of a false positive in one of the negative control samples raises the possibility of the presence of interfering components in the CSF sample from patients with non‐neurodegenerative pathologies.ConclusionOur pilot results illustrate the feasibility of having CJD CSF samples tested in Brazilian centers and highlight the importance of inter‐institutional collaboration to pursue a higher diagnostic accuracy in CJD in Brazil and Latin American.