Variation in concentration of prion protein in the peripheral blood of patients with variant and sporadic Creutzfeldt-Jakob disease detected by dissociation enhanced lanthanide fluoroimmunoassay and flow cytometry.
BACKGROUND
A highly sensitive dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) and flow cytometry techniques have previously been developed and employed to characterize soluble cellular prion protein (PrP(c)) expression in whole blood and separated components from healthy adult blood donors. No previous studies with these techniques have evaluated the concentration and expression of PrP in the blood of patients with variant Creutzfeldt-Jakob disease (vCJD).


METHODS
For blood from vCJD patients, sporadic CJD (sCJD) patients, non-CJD neurological controls, and healthy adults, PrP(c) was measured by DELFIA and cell-associated PrP was measured by flow cytometry.


RESULTS
DELFIA analysis identified a significant reduction in the concentration of PrP(c) in the whole blood of vCJD (p = 0.012) and non-CJD neurological patients (p = 0.0004) compared with healthy adults. A significant elevation was found in plasma PrP(c) in sCJD patients compared with healthy adult (p = 0.022) and neurological controls (p = 0.050). Flow cytometry found no significant differences between groups in expression of PrP on platelets and lymphocytes, nor in sensitivity of cellular PrP to proteinase K. Neurological controls show significantly less PrP on red cells than healthy adults.


CONCLUSIONS
There are differences in free and cell-associated PrP found in blood of CJD patients and control groups, some of which might be useful with other tests in disease profiling as an aid to diagnoses.
Fagge
Tim
T
National Creutzfeldt-Jakob Disease Surveillance Unit, Division of Pathology, School of Molecular and Clinical Medicine, University of Edinburgh, Western General Hospital, Edinburgh, UK. tim.Fagge@ed.ac.uk
Barclay
G Robin
GR
Macgregor
Ian
I
Head
Mark
M
Ironside
James
J
Turner
Marc
M
D000328:Adult; D000367:Age Factors; D007562:Creutzfeldt-Jakob Syndrome / Q000097:blood* / Q000175:diagnosis*; D005434:Flow Cytometry; D015200:Fluoroimmunoassay / Q000379:methods*; D006801:Humans; D028581:Lanthanoid Series Elements; D018621:PrPC Proteins / Q000097:blood*; D012680:Sensitivity and Specificity
D028581:Lanthanoid Series Elements; D018621:PrPC Proteins