Organ distribution of prion proteins in XXXX .

@entity75 @entity1 @entity3669 @entity3605
In this article we give an overview of the transmissible spongiform @entity75 , with emphasis on the evidence for the distribution of abnormal prions in tissues. The normal @entity3669 is distributed ubiquitously throughout @entity1 body tissues. Endogenous expression of the normal @entity3669 , as well as auxiliary proteins, plays a part in accumulation of the abnormal @entity3669 . As exemplified by @entity3605 ( @entity3605 ) the abnormal @entity3669 can accumulate in the host lymphoid system, in particular the follicular dendritic cells. The route for the disease-related prion neuroinvasion is likely to involve the peripheral nervous system. An alternative route may involve blood constituents. Both animal studies and studies on @entity3605 @entity1 suggest a potential for abnormal prion distribution in several peripheral tissues other than the lymphoreticular system. In @entity1 beings the abnormal prion has been reported in the brain, tonsils, spleen, lymph node, retina, and proximal optic nerve. Infectivity, although present in peripheral tissues, is at lower levels than in the central nervous system (CNS). Animal models suggest that the growth of infectivity in the CNS is likely to be gradual with maximum values during the clinical phase of disease. That tissues may harbour the abnormal prion, at different levels of infectivity, during the incubation period of the disease raises concerns of iatrogenic transmission of the disease either after surgery, blood transfusion, or accidental organ transplantation from donors in the preclinical phase of the disease.
