RH LATEX AGGLUTINATION TEST Flashcards
*MATERIALS for rheumatoid factor latex agglutination test
- Rf latex suspension
- Positive and Negative Controls
- Black test cards
- Disposable stirrers
- Mechanical rotator
Principle of the test
*The RF reagent is a suspension of polystyrene latex particles sensitized
with specially prepared human IgG.
The reagent is based on an immunological reaction between human IgG
bound to biologically inert latex particles and rheumatoid factors in the
test specimen. When serum containing rheumatoid factors is mixed
with the latex reagent, visible agglutination occurs.
The RF latex reagent sensitivity has been adjusted to detect a minimum
of ___ of rheumatoid factors
8 IU/mL
RF Latex Reagent
A suspension of uniform polystyrene
particles coated with IgG (human) in glycine buffer, pH 8.2
buffer and the pH used in the rheumatoid factor latex reagent
Glycine-Saline Buffer - pH 8.2 ± 0.1M glycine and 0.15M
NaCl
should we MIX WELL BEFORE USING?
yes
RF Positive Control Serum
A stabilized, prediluted human
serum containing at least 8 IU/mL of RF
RF Negative Control Serum:
A stabilized, prediluted human
serum containing less than 8 IU/mL of RF
*RA is another example of a systemic autoimmune disorder. It affects about
___ of the adult population,
0.5% to 1.0%
do prevalence varies with ethnicity
and geographic location?
yes
which gender is 3 times more likely to be affected by RA?
women
the prevalence of the disease is highest in women who are
more than ___ years of age.
65
RA can be characterized as a
___, ___, and ___ arthritis of
the peripheral joints
chronic, symmetric, and erosive
RA can as well affect multiple organs such as
heart and the lungs
Associations of RA with more than ___ genetic regions have
been discovered.
30
The strongest associations have been between a subset of patients with RA and specific ___alleles/gene
HLA-DRB1 alleles or PTPN22 gene
polymorphisms
The strongest
environmental risk factor for RA is believed to be ____, which
doubles the risk of developing the disease
cigarette smoking
The pathology of RA is caused by an inflammatory process that results in the destruction of ___ and ___.
bone and cartilage
The lesions in rheumatoid joints show an increase in
cells lining the synovial membrane and formation of a ___
pannus
a sheet of inflammatory granulation tissue that
grows into the joint space and invades the cartilage
pannus
*Infiltration of the inflamed synovium with ___s
within the joint
T and B lymphocytes, plasma cells, dendritic cells, mast cells, and granulocytes
*It is not known what role autoantibodies play in the initiation of the
inflammatory response.
Two key antibodies found in the disease are ___ and ___
RF and anti-CCP.
*RF is an antibody that is most often of the ____ class and is directed against
the FC portion of ___
IgM; IgG
It has been postulated that RFs may play a role in the pathogenesis of RA by increasing ___ activity and enhancing
antigen presentation to T cells by ___.
macrophage; APCs
*The complement protein __ binds to the immune complexes, activating the
classical complement cascade
C1
The complement protein C1 binds to the immune complexes, activating the
classical complement cascade.
During this process,___and __ are
generated, which act as chemotactic factors for neutrophils and
macrophages.
C3a and C5a
Diagnosis of RA is based on a combination of ___
clinical manifestations, radiographic findings, and laboratory testing.
*___ is the antibody that is most often tested to aid in making
the initial diagnosis.
RF
Approximately__ of patients with RA test positive
for RF.
70% to 90%
a negative result does not rule out the
presence of RA.
true
true
Conversely, a positive test result is not
specific for RA because RF is also present in about ___ of
healthy individuals
5%
Conversely, a positive test result is not
specific for RA because RF is also present in about 5% of
healthy individuals and in ___ of those over the age
of 65
10% to 25%
RF can be found in patients with other
connective tissue diseases such as
SLE, Sjögren’s
syndrome, scleroderma, and mixed connective tissue disease, as well as in people with some chronic infections
*Manual agglutination tests using __ have been used for many years
to detect RF
charcoal or latex particles coated with IgG
manual agglutination test using charcoal or latex particles, These tests, however, only detect the __ isotype
IgM
manual agglutination test, this kind of test found the IgM isotype in about _% of patients
75%
Manual agglutination tests have been largely replaced
by ___ which are automated, have
greater precision and sensitivity, and can also detect other RF isotypes
ELISA, chemiluminescence immunoassay, and
nephelometric methods
*Once a diagnosis of RA is made, the most helpful tests
for following the progress of the disease are ___
general indicators of inflammation
general indicators of inflammation such as measurement of ___
ESR, CRP, and complement components.
Typically, __ and ___ are elevated and the levels of
serum complement components are NORMAL or increased because of increased acute-phase reactivity
CRP and ESR
___ levels correlate well with disease activity because levels reflect the intensity of the inflammatory
response
CRP
Results should be read within minutes after the mixing
or the reagent on the slide
two (2)
Existence of prozone at high titers has not been
encountered.
true or false
true
Increased levels of RF may be found in some diseases other than rheumatoid arthritis such as ____
infectious mononucleosis, sarcodosis, lupus erythematosus, Sjogren’s syndrome.
Certain patients with rheumatoid arthritis will not have
the RF present in their serum
true or false?
true
The diagnosis of rheumatoid arthritis is based largely on __
clinical examination
The diagnosis of rheumatoid arthritis is based largely on
clinical examination, but ___ are useful to support the clinical diagnosis and to evaluate the severity and course or the disease in the individual patient.
laboratory tests
One of the most useful clinical markers for rheumatoid arthritis is ___r in serum.
rheumatoid factor
___ is a term used to describe a variety of
antibodies or immune complexes or both, that occur with
rheumatoid arthritis as well as in a variety of other diseases.
Rheumatoid factor
Different studies have shown positive serological reactions
for rheumatoid factor in as high as ___ of patients with
rheumatoid arthritis compared with less than 5% in control groups
90%
Reagents are stable until stated expiration date on
bottle label when stored refrigerated ___.
(2 - 8°C)
can we freeze the reagent while storing?
nope, DO NOT FREEZE
The RF latex reagent, once shaken must be ___
uniform without visible clumping
When stored refrigerated, a
slight ___ may occur and should be
considered normal
sedimentation
