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.
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.
Vidal
E
E
Priocat Laboratory, CReSA, Autonomous University of Barcelona, Bellaterra (Cerdanyola del Vallès), Spain.
Tortosa
R
R
Costa
C
C
Benavides
J
J
Francino
O
O
Sánchez-Robert
E
E
Pérez
V
V
Pumarola
M
M
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
D018620:PrPSc Proteins