ARS | Publication request: PRP SC IS NOT DETECTED IN PERIPHERAL BLOOD LEUKOCYTES OF SCRAPIE INFECTED SHEEP: DETERMINING THE LIMIT OF SENSITIVITY BY IMMUNOHISTOCHEMISTRY

Submitted to: Clinical and Diagnostic Laboratory Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 18, 2001
Publication Date: N/A

Interpretive Summary: Scrapie is part of a group of neurodegenerative diseases called transmissible spongiform encephopathies (TSE's). Natural sheep scrapie continues to be spread in flocks in the United States, and peripheral blood cells remain one possible source of transmission. Peripheral blood cells from scrapie-infected sheep were evaluated for the presence of PrPSc using dissociated lymph node cells and immunohistochemistry (IHC). PrPSc positive cells were detected in 2% of dissociated lymph node cells, but were not detected in 3,000,000 peripheral blood cells. Mixing dissociated lymph node cells with blood cells showed IHC detects a minimum of 60 PrPSc positive cells in 3,000,000 blood cells.

Technical Abstract: Peripheral blood leukocytes (PBL) from scrapie-infected sheep were evaluated for the presence of PrPSc using dissociated retropharyngeal lymph node cells (DRLN) and immunohistochemistry (IHC). PrPSc positive cells were detected in 2.05% with a variance of .28% of 3,000,000 DRLN cells but were not detected in 3,000,000 PBL from scrapie-infected sheep. Titration of DRLN cells mixed with PBL showed IHC detects a minimu of 0.00205% or 60 PrP Sc positive cells in 3,000,000 PBL.