Diagnosis of prion diseases by RT-QuIC results in improved surveillance

Objective:  We present the National Prion Disease Pathology Surveillance Center’s (NPDPSC) experience using cerebrospinal fluid (CSF) real time quaking induced conversion (RT-QuIC) as a diagnostic test, examine factors associated with false negative RT-QuIC results, and investigate RT-QuIC’s impact on prion disease surveillance. 

 

Methods:  Between May 2015-April 2018, the NPDPSC received 10,498 CSF specimens that were included in the study.   Sensitivity and specificity analyses were performed using 567 autopsy verified cases.  Prion disease type, demographic characteristics, specimen color, and time variables were examined for association with RT-QuIC results.  The effect of including positive RT-QuIC cases in prion disease surveillance was examined.

 

Results: The diagnostic sensitivity and specificity of RT-QuIC across all prion diseases was 90.3% and 98.5%, respectively.  Diagnostic sensitivity was lower for fatal familial insomnia, Gerstmann-Sträussler-Scheinker disea...