Prion Infections

on 30.1.09 with 0 comments

  • CJD

    • Most common prion disease in humans; typically seen in older people

    • Starts with subtle behavior changes followed by rapid progressive dementia (most rapidly progressive of human prion diseases – uniformly fatal within a year of c/s onset)

    • Startle myoclonus is common in later stages

    • Transmitted by exposure to eye and neural tissue products, but there are familial and sporadic forms

  • vCJD (new vCJD)

    • Seen in younger patients

    • Associated with consumption of BSE beef

    • More protracted than is classic CJD

  • Kuru – cannibals in Papua/New Guinea

  • Scrapie

  • Mink encephalopathy

  • BSE

  • Gerstmann-Straussler-Schenker syndrome – presents with progressive ataxia

  • Familial fatal insomnia – characterized by sleep disturbances leading to dementia

  • Kuru plaques can be seen in all of the prion diseases (these are amyloid plaques)

  • Pathogenesis of prion diseases in general

    • Prion protein (PrP) is a normal protein that we all make

    • Some folks have a PrP that is prone to change from its alpha helix to a beta pleated sheet; when this happens, it encourages other PrP around it to change conformation as well (now called PrPSC)…lots of PrPSC cause spongiform changes – this explains how prion disease can be acquired and spontaneous

    • If you don’t make PrP you are immune from prion diseases

    • PrPSC is very resistant to proteases, heat, and steam (autoclaving)

Category: Pathology Notes



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