Detection of prion infection in variant Creutzfeldt-Jakob disease

January 01, 0001

Detection of prion infection in variant Creutzfeldt-Jakob disease

The researchers from the UK aimed to establish the sensitivity and specificity of a blood-based assay for detection of vCJD prion infection. They developed a solid- state binding matrix to capture and concentrate disease- associated prion proteins and coupled this method to direct immunodetection of surface-bound material. Quantitative assay sensitivity was assessed with a serial dilution series of 10-7 to 10-10 of vCJD prion-infected brain homogenate into whole human blood, with a baseline control of normal human brain homogenate in whole blood (10-6). To establish the sensitivity and specificity of the assay for detection of endogenous vCJD, they analysed a masked panel of 190 whole blood samples from 21 patients with vCJD, 27 with sporadic CJD, 42 with other neurological diseases, and 100 normal controls. Samples were masked and numbered by individuals independent of the assay and analysis. Each sample was tested twice in independent assay runs; only samples that were reactive in both runs were scored as positive overall.

They were able to distinguish a 10-10 dilution of exogenous vCJD prion-infected brain from a 10-6 dilution of normal brain (mean chemiluminescent signal, 1.3×105 for vCJD vs 9.9×104 for normal brain)—an assay sensitivity that was orders of magnitude higher than any previously reported. 15 samples in the masked panel were scored as positive. All 15 samples were from patients with vCJD, showing an assay sensitivity for vCJD of 71.4% and a specificity of 100%.

The researchers concluded: "These initial studies provide a prototype blood test for diagnosis of vCJD in symptomatic individuals, which could allow development of large-scale screening tests for asymptomatic vCJD prion infection."

This would be a great bonus for blood transfusions and tissue grafts.

For the full abstract, click here.

The Lancet 377 (9764):487-493, 5 February 2011 © 2011 Elsevier Limited
The angiotensin-receptor blocker candesartan for treatment of acute stroke (SCAST): a randomised, placebo- controlled, double-blind trial. Else Charlotte Sandset, Philip MW Bath, Gudrun Boysen et al on behalf of the SCAST Study Group. Correspondence to Eivind Berge: [email protected]

Category: K. Circulatory. Keywords: candesartan, acute stroke, blood pressure, randomised, placebo-controlled, double-blind trial, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 25 February 2011

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