OBJECTIVE QUANTIFICATION OF PRION PROTEIN IN SPINAL-CORDS OF CASES OFCREUTZFELDT-JAKOB-DISEASE

A recent investigation into prion protein (PrP) deposition in cases of Creutzfeldt-Jakob disease (CJD) has suggested that the spinal cord is affected in some cases of this disease. in an attempt to measure this phenomenon we have used quantitative image analysis techniques to ass ess the amount of PrP deposited in the spinal cords of three different cases of CJD. By using an automatic method of image intensity thresho ld setting we have measured the tissue area occupied by PrP in a non-s ubjective manner. The ranking of these different cases has confirmed t hat suggested by visual inspection. This analysis shows a substantial variation in the quantity of PrP positivity observed when a panel of d ifferent PrP antibodies was compared, confirming early findings. The d istribution of PrP across the spinal cord has also been mapped using t he image analysis system.