Specificity of lymphoreticular accumulation of prion protein for variant Creutzfeldt-Jakob disease

Background: Immunocytochemical accumulation of prion protein (PrP) in lymphoid tissues is a feature of variant Creutzfeldt-Jakob disease (vCJD) that has been used both to aid in the diagnosis of patients and as a basis of large scale screening studies to assess the prevalence of preclinical disease in the UK. However, the specificity of this approach is unknown. Aim: To assess the specificity of lymphoreticular accumulation of PrP for vCJD by examining a range of human diseases. Methods: Paraffin wax embedded lymphoreticular tissues from patients with several reactive conditions (58 cases), tumours (27 cases), vCJD (54 cases), and other human prion diseases ( 56 cases) were assessed. PrP accumulation was assessed by immunocytochemistry using two different monoclonal anti-PrP antibodies and a sensitive detection system. Results: All cases of vCJD showed widespread lymphoreticular accumulation of PrP; however, this was not seen in the other conditions examined. Conclusion: Lymphoreticular accumulation of PrP, as assessed by immunocytochemistry, appears to be a highly specific feature of vCJD.