Journal of Medical Virology,
Journal Year:
2023,
Volume and Issue:
95(8)
Published: Aug. 1, 2023
The
circulating
nucleocapsid
(NCP)
antigen
of
severe
acute
respiratory
syndrome
coronavirus
2
(SARS-CoV-2)
is
detectable
in
disease-2019
(COVID-19)
patients.
To
better
understand
the
biology
disease
severity,
we
investigated
NCP
clearance
kinetics
hospitalized
COVID-19
Serum
was
quantified
using
a
commercial
NCP-specific
enzyme-linked
immunoassay
patients
(n
=
63)
during
their
hospital
stay.
Results
were
correlated
to
inflammation
parameters,
antibody
response,
and
results
SARS-CoV-2
PCR
from
nasopharyngeal
swabs.
We
demonstrate
that
levels
serum
remained
elevated
21/45
(46.7%)
samples
intensive
care
units
(ICU)
after
>8
days
postdiagnosis.
proportion
ICU
with
antigenemia
declined
only
gradually
84.6%
25.0%
over
several
weeks.
This
contrast
complete
all
non-ICU
8
days,
also
mucosal
virus
as
measured
by
PCR.
Antigen
associated
higher
IgG
against
S1
but
not
NCP.
Clearance
delayed
>40%
severely
ill
Thus,
detected
post
diagnosis
characteristic
requiring
care.
Prospective
trials
should
further
investigate
mechanistic
biomarker.
npj Viruses,
Journal Year:
2024,
Volume and Issue:
2(1)
Published: Sept. 2, 2024
Abstract
Nucleocapsid
protein
(N),
or
nucleoprotein
(NP)
coats
the
genome
of
most
RNA
viruses,
protecting
and
shielding
from
cytosolic
RNAases
innate
immune
sensors,
plays
a
key
role
in
virion
biogenesis
viral
transcription.
Often
one
highly
expressed
gene
products,
N
induces
strong
antibody
(Ab)
T
cell
responses.
different
viruses
is
present
on
infected
surface
copy
numbers
ranging
tens
thousands
to
millions
per
cell,
it
can
be
released
bind
uninfected
cells.
Surface
targeted
by
Abs,
which
contribute
clearance
via
Fc-mediated
cellular
cytotoxicity.
modulate
host
immunity
sequestering
chemokines
(CHKs),
extending
prior
findings
that
interferes
with
adaptive
immunity.
In
this
review,
we
consider
aspects
biology
immunology
describe
its
potential
as
target
for
anti-viral
intervention.
Clinical Chemistry and Laboratory Medicine (CCLM),
Journal Year:
2022,
Volume and Issue:
61(2), P. 316 - 322
Published: Oct. 31, 2022
This
proof
of
concept
study
was
aimed
to
validate
the
hypothesis
that
time
positivization
SARS-CoV-2
self-performed
rapid
diagnostic
tests
(RDTs)
may
reflect
actual
viral
load
in
specimen.A
positive
sample
with
high
diluted
and
concomitantly
assayed
molecular
assay
(Xpert
Xpress
SARS-CoV-2)
RDT
(COVID-VIRO
ALL
IN
RDT).
The
(mean
cycle
threshold;
Ct)
values
times
these
dilutions
were
plotted
interpolated
by
calculating
best
fit.
parameters
this
equation
then
used
for
converting
into
RDT-estimated
Ct
routine
patient
samples.The
fit
between
measured
could
be
achieved
a
2-degree
polynomial
curve.
exhibited
correlation
(r=0.996)
excellent
Deming
(y=1.01
×
x
-
0.18)
values.
In
30
consecutive
patients
test,
value
r=0.522
(p=0.003).
slightly
improved
0.577
(Deming
fit:
y=0.44
+
11.08),
displaying
negligible
bias
(1.0;
95%
CI,
-0.2
2.2;
p=0.105).
Concordance
at
<20
cut-off
80%,
0.84
sensitivity
0.73
specificity.This
demonstrates
potential
feasibility
using
RDTs
garnering
information
on
acute
infection.
Open Forum Infectious Diseases,
Journal Year:
2023,
Volume and Issue:
10(8)
Published: July 10, 2023
Abstract
Data
on
the
performance
of
blood-based
nucleocapsid
antigen
tests
for
diagnosing
severe
acute
respiratory
syndrome
coronavirus
2
(SARS-CoV-2)
infection
and
infectious
viral
shedding
are
limited.
To
address
this
knowledge
gap,
we
conducted
a
systematic
review
to
assess
(N)
in
SARS-CoV-2
identifying
infectiousness.
This
was
registered
PROSPERO
(registration
no.
CRD42022339635).
We
comprehensively
searched
PubMed,
Embase,
Web
Science,
Coronavirus
Research
Database
relevant
studies
published
through
27
February
2023.
Each
study's
risk
bias
evaluated
using
Quality
Assessment
Diagnostic
Accuracy
Studies
(QUADAS-2)
tool.
Our
findings
indicate
that
N-antigen
test
is
influenced
by
factors
such
as
assay
type,
sampling
timing,
illness
severity.
Sensitive
assays
provide
suitable
methods
viable
screening
laboratory
diagnostic
different
clinical
research
settings
during
early
phase
illness.
Journal of Medical Virology,
Journal Year:
2023,
Volume and Issue:
95(8)
Published: Aug. 1, 2023
The
circulating
nucleocapsid
(NCP)
antigen
of
severe
acute
respiratory
syndrome
coronavirus
2
(SARS-CoV-2)
is
detectable
in
disease-2019
(COVID-19)
patients.
To
better
understand
the
biology
disease
severity,
we
investigated
NCP
clearance
kinetics
hospitalized
COVID-19
Serum
was
quantified
using
a
commercial
NCP-specific
enzyme-linked
immunoassay
patients
(n
=
63)
during
their
hospital
stay.
Results
were
correlated
to
inflammation
parameters,
antibody
response,
and
results
SARS-CoV-2
PCR
from
nasopharyngeal
swabs.
We
demonstrate
that
levels
serum
remained
elevated
21/45
(46.7%)
samples
intensive
care
units
(ICU)
after
>8
days
postdiagnosis.
proportion
ICU
with
antigenemia
declined
only
gradually
84.6%
25.0%
over
several
weeks.
This
contrast
complete
all
non-ICU
8
days,
also
mucosal
virus
as
measured
by
PCR.
Antigen
associated
higher
IgG
against
S1
but
not
NCP.
Clearance
delayed
>40%
severely
ill
Thus,
detected
post
diagnosis
characteristic
requiring
care.
Prospective
trials
should
further
investigate
mechanistic
biomarker.
