Immunoquantitative PCR for Prion Protein Detection in Sporadic Creutzfeldt–Jakob Disease

Background: The most common human prion disorder is Creutzfeldt–Jakob disease (CJD); it includes sporadic, familial, iatrogenic, and variant subtypes. Diagnostic tests aim at detection with the highest specificity of very small deposits of abnormal prion protein (PrP). Methods:We used immunoquantitative PCR (iqPCR) to detect proteinase K–resistant PrP (PrPRes) in tissue from the middle frontal gyrus of 7 patients with sporadic CJD and 7 non-CJD cases. We compared iqPCR with routine optimized ELISA, Western blotting, and immunohisto-chemical analyses. Results: The 4 methods showed similar 100 % sensitivity and specificity for the diagnosis of CJD. Along with high specificity, however, iqPCR had a threshold for PrPRes detection at least 10-fold lower than that of th