Chroni
Biomedical
Page 3 of 10
The Goettingen Living Test
For BSE-Susceptibility
Name and Intended Use
The Goettingen Living Test (GLT) for
bovine
spongiform
encephalopathy
(BSE) susceptibility is a genetic test for
the in vitro detection of circulating
nucleic acids (CNA). This test is
intended for use in professional
laboratory settings as a living test for
assessing cattle's risk of developing
bovine spongiform encephalopathy.
Cattle showing repeat reactivity in this
test should be considered at risk for
developing BSE. Further testing will be
required to determine the level of risk an
animal may have for developing BSE.
Summary and Explanation of the
Test
BSE is a progressive neurodegenerative
disease in cattle. The presence of BSE
cattle in the food supply presents a
public health concern to humans.
Current tests for BSE are performed only
at necropsy (post mortem) and therefore
limit efforts to eliminate BSE animals
from living herds. The Goettingen
Living Test for BSE-susceptibility is a
living test (ante mortem) for the
detection of abnormal CNA profiles in
cattle. CNA profiles are an indication of
a host's response to toxic exposures. In-
house clinical data support the concern
that cattle with abnormal CNA patterns
may be at a significantly increased risk
for developing BSE. Because BSE
pathogenesis remains mysterious and
there is a medically acknowledged risk
of transmission to humans, GLT reactive
samples should be handled as potentially
infectious until further testing can
confirm its handling status.
Principles of the Test
Epidemiologic efforts for controlling
disease require robust test procedures
that identify and monitor at-risk
individuals. To date, a group of chronic
illnesses referred to as the transmissible
spongiform encephalopathies (TSEs) has
shown the presence of a misfolded
natural protein, the prion protein. In its
naturally-occurring
properly-folded
configuration, the prion protein is not
associated with disease; its misfolded
form, known as PrP
res
, is associated with
TSEs. The confirmation test for animals
with TSE is the post mortem direct
detection of PrP
res
in the brain. Because
natural antibodies to PrP
res
are rare,
immunoassay tests for the detection of
PrP
res
antibodies in living animals (ante
mortem) are not feasible. Another ante
mortem epidemiologic approach is the
detection of circulating nucleic acids
(CNA). CNA are an effective laboratory
means for monitoring events in diseases
associated with viral gene sequences.
Chronix Biomedical has developed and
validated a CNA test for the detection of
BSE-risk in living herds. The GLT for
BSE-susceptibility is based on many of
the same principles as the tests used to
monitor viral diseases. The GLT detects
nucleic acids in the liquid portion of
blood known as serum or plasma. The
nucleic acid sequences detected in the
