title: Lack of PrP(sc) immunostaining in intracranial ectopic lymphoid follicles in a sheep with concomitant non-suppurative encephalitis and Nor98-like atypical scrapie: a case report.
abstract: During active surveillance for transmissible spongiform encephalopathies (TSEs) in sheep, an initial reactor was detected using a rapid test on a brain sample. Immunohistochemistry confirmed an atypical TSE presentation that closely resembled the previously described Nor98 cases. Sequencing of the prnp gene confirmed the ARQ/AHQ genotype with the L141F mutation at codon 141 associated with this phenotype. The head, including the brain and cranial lymphoid tissues, was sampled and examined thoroughly. Non-purulent encephalitis, with ectopic lymphoid follicle formation within the brain, was diagnosed concomitant to the TSE. When scrapie-associated prion protein (PrP(sc)) deposition was studied by immunohistochemistry there was a noticeable lack of lymphotropism. The distribution of PrP(sc) in the brain differed considerably from that of classical scrapie cases. Astrogliosis and microgliosis were demonstrated by histochemical procedures.
authors.affiliation: Priocat Laboratory, CReSA, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
authors.forename: E
authors.initials: E
authors.lastname: Vidal
authors.forename: R
authors.initials: R
authors.lastname: Tortosa
authors.forename: C
authors.initials: C
authors.lastname: Costa
authors.forename: J
authors.initials: J
authors.lastname: Benavides
authors.forename: O
authors.initials: O
authors.lastname: Francino
authors.forename: E
authors.initials: E
authors.lastname: Sánchez-Robert
authors.forename: V
authors.initials: V
authors.lastname: Pérez
authors.forename: M
authors.initials: M
authors.lastname: Pumarola
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004660:Encephalitis / Q000150:complications / Q000662:veterinary* / Q000821:virology; D007150:Immunohistochemistry; D018620:PrPSc Proteins / Q000302:isolation & purification*; D012608:Scrapie / Q000150:complications*; D012756:Sheep; D013194:Staining and Labeling
chemical_list: D018620:PrPSc Proteins