NR AWPZ
AU Vidal,E.; Marquez,M.; Serafin,A.; Domenech,A.; Pumarola,M.
TI Neuropathological characterisation of an atypical Spanish case of scrapie
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions PA-58
PT Konferenz-Poster
AB The brain of a cross breed sheep analysed within the TSE active surveillance program was referred to our lab (PRIOCAT, TSE regional reference lab in Catalonia) as an initial reactor to the first rapid test (TeSeE ELISA, Biorad). The ELISA test was repeated not only in medulla oblongata samples but also in the cerebellum. In parallel, a second rapid test, Prionics-Check Western Blott, was also performed. The cerebellum yielded a higher positive ELISA score than the medulla and both samples were negative to Western Blott. Immunohistochemistry on formalin fixed, paraffin embedded tissue samples confirmed the presence of prion protein deposits, which were more intense at the granular layer of the cerebellum, mild punctiform deposits where also observed at the medulla oblongata. The case was diagnosed as an atypical presentation of scrapie, similar to those described as Nor98 cases. A discriminatory test was also performed (western blotting with antibodies against the prion proteins' N-terminus/core: P4/6H4) and ruled out a possible case of BSE in sheep. The prnp was sequenced and the animal belonged to the AA136RH154QQ171 genotype, thus belonging to NSP Group 3 (animals with little resistance to scrapie), moreover it had a heterozygous phenylalanine substitution in codon 141. The whole brain of the animal was sampled and neuropathological characterisation was performed. Half of the brain was formalin fixed and paraffin embedded. Haematoxylin-eosin stained sections were used to evaluate the morphological changes: spongiform lesions where minimal but a non purulent inflammatory infiltrate constituted mainly by macrophages, lymphocytes and plasma cells was observed as perivascular cuffs located sub-ventricularly, at the leptomeninges and choroid plexuses. Remarkably, in the third ventricle, the formation of lymphoid germinal centres was observed. A morphological diagnosis of concomitant Visna encephalitis was made. Further slides where processed for PrPsc IHQ to map the whole brain distribution of the prion protein deposition. The lymphoid organs tested, including third eyelid, palatine tonsil, retropharyngeal lymph node and the inflammatory infiltrate itself were PrPsc negative. Other parameters evaluated were gliosis (GFAP), cellular death (C3A), extracellular matrix (WFA) and the calcium binding proteins parvalbumin and Calbindin D28K positive GABAergic neural population.
AD E. Vidal: Priocat Laboratory, CReSA, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Spain; M. Márquez, A. Serafín, A. Domènech: Animal tissue bank of Catalonia (BTAC), Animal Medicine and Surgery Department, Veterinary Faculty, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Spain; M. Pumarola: Priocat Laboratory, CReSA, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Spain, and Animal tissue bank of Catalonia (BTAC), Animal Medicine and Surgery Department, Veterinary Faculty, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Spain
SP englisch
PO Italien