autoimmunity Flashcards
A cold agglutinin titer end point is 1:16 after incubating overnight in the refrigerator and remains 1:16 after warming. The best course of action is to
report the titer as negative
test for antibody specificity
A false-negative cold agglutinin test may result if:
the specimen is refrigerated prior to serum separation
How should blood collected for a cold agglutinin determination BEST be treated before serum is separated for testing?
allow to clot at 37C
An example of a Type IV hypersensitivity reaction is:
a. allergic rhinitis
b. autoimmune hemolytic anemia
c. systemic lupus erythematosis
d. contact dermatitis
d. contact dermatitis
In the radial
immunodiffusion
(RID) procedure, which of the following pairs describe the locations of the reactants? a. antigen in the well, antibody in the agar
b. antibody in the well, antigen in the agar
c. antigen and antibody in individual wells
d. antigen in he well, antibody in the trough
a. antigen in the well, antibody in the agar
Antibodies to nDNA in the diagnosis of systemic lupus may be detected utilizing the protozoan Crithidia luciliae. The portion of the organism which will fluorescein a positive test is the
Kinetoplast
Nucleus
A peripheral patter in an antinuclear antibody (ANA) test is MOST characteristic of which disease listed?
a. Active systemic lupus erythematosus
b. Sjogren syndrome
c. Progressive systemic sclerosis
d. Scleroderma
a. Active systemic lupus erythematosus
Which
immunoglobulin
is associated with allergic reactions?
IgE
A patient has the following test results:
ANA = Positive 1:320
RA = Positive
Complement = Increased
ASO = 50 Todd Units
The above results would be seen in patients with:
Rheumatoid arthritis
A child has severe hay fever. A total IgE measurement was performed by the Ouchterlony
immunodiffusion method. No lines ofprecipitation appeared on the
immunodiffusion
plate. The most likely explanation is:
IgE is too low in concentration to be detected by this method
In systemic lupus
erythematosus
, high levels of which of the following antibodies are seen?
anti-DNA
Immediate Hypersensitivity
Type I Hypersensitivity
Allergy
Type I Hypersensitivity
Rheumatic Fever
Type III Hypersensitivity
Delayed Hypersensitivity
Type IV Hypersensitivity
Poison Ivy
Type IV Hypersensitivity
Innocent Bystander Destruction of Tissue
Type III Hypersensitivity
Host Rejection of Transplant Organs
Type IV Hypersensitivity
Rheumatoid Arthritis
Type III Hypersensitivity
Glomerulonephritis
Type III Hypersensitivity
Antigen-Antibody Complexes
Type III Hypersensitivity
Hemolytic Disease of the Newborn
Type II Hypersensitivity
Thrombocytopenia purpura
Type II Hypersensitivity
Which of the
immunoglobulins
is present in the highest concentration in normal human serum?
IgG
Which of the following best described the slide agglutination test for rheumatoid factor?
it detects IgM autoantibodies made against the patient’s own IgG
Cold agglutinins often occur in which disease state(s) and have what specificity?
primary atypical pneumonia, Anti-I
infectious mononucleosis, Anti-i
In the direct fluorescent antinuclear antibody test, a speckled pattern, especially with symptoms of SLE, may indicate the presence of antibody to:
RNP
The result of an antinuclear antibody test was a titer of 1:320 with a peripheral pattern. Which of the following sets of results bestcorrelates with these results?
a. anti-dsDNA titer 1:160, and a high titer of antibodies to Sm
b. anti-mitochondrial antibody titer 1:160, and antibodies to Sm
c. anti-r-6s RNP, and antibodies to single stranded DNA
d. high titers of anti-ssDNA and anti-centromere
a. anti-dsDNA titer 1:160, and a high titer of antibodies to Sm
What type of antibodies are represented by the peripheral or rim pattern of
immunofluorescence
in tests for antinuclear antibody?
Anti-dsDNA antibodies
What type of antibodies are represented by the solid or
homogeneous
pattern in the
immunofluorescence
test for antinuclear antibody?
Anti-histone antibodies
In chronic active hepatitis, high titers of which of the following antibodies are seen?
Anti-smooth muscle
What antibodies are represented by the nucleolar pattern in the
immunofluorescence
test for antinuclear antibody?
Anti-RNA antibodies
Detection of which of the following substances is most useful in monitoring the course of a patient with testicular cancer?
Alpha feto-protein
factors influencing autoimmunity
genetic: familial propensity
women>men
increased in HLA types
Increased w/ age
classification of autoimmunity: organ specific examples
endocrine disorders (Hashimotos, Graves)
pernicious anemia
myasthenia gravis
classification of autoimmuntiy: non organ specific examples
lupus
scleroderma
rheumatoid arthritis
idiopathic
genetic predisposition
1-2% incidence worldwide
30-50 yo
female>male
all ages/races
immunologic manifestation of rheumatoid arthritis
inciting event
rheumatoid factor formed: IgM against patients own IgG (Fe fragment)
heterogeneous grp of immune cmplxs formed in serum and joint fluid
testing for rheumatoid arthritis
rheumatoid factor: latex agglutination (latex bead coated w/ IgG
RF present= agglutination
Antinuclear Antibodies (ANA): fluorescent technique
systemic lupus erythematosus
idiopathic
autoantibodies against basement membranes in vascular system
hormonal influence (females btwn puberty and menopause)
african americans and native americans higher incidence
drug induced systemic lupus erythematosus
birth control pills, procainamide
symptoms of systemic lupus erythmatosus
inflamm
photosensitivity and facial rash
diffuse arthritis
renal, cardiac, respiratory, CNS involvement
poly arthritis and skin rash most common
testing for systemic lupus erythmatosus
LE prep (LE cell)
ANA (only nucleus reacts w/ auto Ab
scleroderma
rare autoimmune disease affecting blood vessels and connective tissues
fibrous degeneration of conn. tiss. of skin and internal organs
“progressive scleroderma”
CREST variant
Sjorgren’s
autoimmune disorder assoc. w/ deficient moisture prod. of mouth, eyes, mucous membranes
cold agglutinin testing
cold auto Ab
anti-i specificity (all adult O cells have anti-I on RBC anti-i only as newborn)
produced in adults during 1* atypical pneumonia (like Mycoplasma pneumonia)
test lacks sentivity
procedure of cold agglutinin test
draw serum
keep warm (37*C) until serum separated from cells (to prevent false -)
make serial dilutions
add grp O washed cells
incubate overnight
look for aggluntination and read titer
precipitation reactions: radial immunodiffusion
gel contains Ab
sample diffuses away from sample well
protein Ag or immunoglobulin ppt at zone of equivalence
ppt rxns: Mancini RID endpoint method
take Z of E to exact endpoint
readings stable at this point
plot the diameter squared on regular graph paper
ppt rxns: Fahey RKID timed diffusion method
read at pre-determined time (18 hrs)
reading unstable unless endpoint is reached
use semi-log paper and plot the ring diameter against [ ]
ppt rxns: Ouchterlony immunodiffusion
Ab loaded in center well
Ag being tested loaded in outer wells
arcs of ppt. are formed: complete identify- boomerang pattern
partial identify pattern
non identify pattern
ppt. rxns: Rocket electrophoresis
similar to RID
standards and patients in wells along on end of gel
electrical current applied across gel forming a rocket pattern at zone of equivalence
ppt. rxns: immunoelectrophoresis
patient serum added to wells and fractions separated similar to electrophoresis
after separation antiserum added to each trough and allowed to diffuse overnight
ppt arcs are formed to [ ] of antisera added
