immunology Flashcards
immune system recognizes what
“self” from “non-self”
what organisms are seen as “non-self” by immune system
- viruses
- bacteria
- parasites
- foreign substances, including allergens
they are attacked by immune system
name autoimmune diseases- major ones
- autoimmune thyroiditis, hashimoto’s
- SLE
- RA
what happens in autoimmune diseases
immune system sees “self” as “nonself”
what is the immune response to non-self, what kind of symptoms occur
fever, hypotension, body aches, generalized not feeling well, fatigue
anaphylaxis can occur (IgE and mast cell mediated)
what happens to genes with immunodeficiencies
can be single gene defect or multiple gene defect
what is anti-nuclear antibody, ANA
antibodies against nuclear components that act as antigens
produced by immune system when it fails to adequately distinguish ‘self’ and ‘non-se;f’
target substances found in nucleus of cell, causes organ and tissue damage
when is ANA used
as initial test to evaluate for autoimmune diseases
if positive more testing is needed
for what s/s is ANA ordered
vague s/s that are associated with systemic autoimmune disorder
Low-grade fever
Persistent fatigue, weakness
Arthritis-like pain in one or morejoints
Red rash (ex: a butterfly rash in lupus)
Skin sensitivity to light
Hair loss
Muscle pain
Numbness or tingling in the hands or feet
Inflammation and damage to organs and tissues
what suggests autoimmune disorder
positive ANA and s/s of autoimmune disease
however, further eval is required
can you see increase in ANA before s/s present
yes
how is ANA reported
as a titer and pattern
relationship of ANA in SLE
95% of ppl with SLE test have positive ANA results
negative ANA makes SLE unlikely
conditions with positive ANA, along with percentages
- SLE, 95%
- Sjogren’s, 40-70%
- scleroderma (systemic sclerosis), 60-90%
- raynauds syndrome
- arthritis
- dermatomyositis or polymyositis
- mixed connective tissue disease
- drug induced lupus (antihistone antibody)
what are the different ANA patterns
- homogenous (diffuse)
- speckled
- nucleolar
- centromere pattern (peripheral)
not always one definitive pattern
ANA homogenous (diffuse) pattern is seen with what diseases
SLE, mixed connective tissue disease, drug induced lupus
what causes drug induced lupus
anticonvulsants, hydralazine, procainamide, isoniazid
what diseases are seen with ANA pattern- speckled
SLE, Sjogren’s, scleroderma, polymyositis, RA, mixed connective tissue disease
what diseases are seen with ANA pattern nucleolar
associated with scleroderma and polymyositis
what diseases are seen with ANA pattern, centromere (peripheral)
scleroderma and CREST
is there a need for serial ANAs
no, ANA is not used to rack or monitor clinical course of disease
ANA false positives occur when
in about 3-5% of healthy adults
may reach as high as 10-37% in adults over 65 y/o bc ANA frequency increases with age
more common in women than men
Which of the following is true of the ANA test?
a. It is a test for the titer and pattern of nuclear antigens in the patients blood.
b. The technique uses fluorescence to detect antibodies to nuclear components.
c. When positive it is diagnostic of SLE and further testing is unnecessary.
d. It is a good general screening test used for routine comprehensive examination of outpatients.
: b. ANA is a test for antibodies to nuclear components, not nuclear antigen.
It is ordered for patients with symptoms and when positive, further testing is in order. It is not a good general screening test for asymptomatic people.
When positive it is not diagnostic of SLE but can tell us there is an autoimmune disease is likely present
what is C reactive protein, CRP
general marker for infection and inflammation
is CRP specific
no, not enough to diagnose a particular disease
must be used in combo or cluster of dx testing
CRP used for what
to detect or monitor significant inflammation in various conditions
infection, autoimmune disease, response to treatment, CVD death risk predictor
what organ is CRP manufactured in
liver
how does CRP participate in activation of immune system
by coating antigens for targeting by complement system
so when immune system is activated and is overactive you see elevated CRP
other things that cause CRP to elevate
Plaques, psoriasis, plaques in brain, plaques in blood vessels, anything that will cause systemic inflammation will cause CRP to elevate
later stages in pregnancy
use of PO contraceptives or hormone replacement therapy (estrogen)
obesity
high sensitivity CRP ranges
Low risk: less than 1.0 mg/L
Average risk: 1.0 to 3.0 mg/L
High risk: above 3.0 mg/L
Which is true of CRP?
a. It is a specific test for atheromatous cardiovascular disease.
b. It is a protein manufactured in the bone marrow.
c. CRP participates in the activation of the immune system.
d. Is elevated when the WBC count is elevated.
Correct answer : c.
CRP is manufactured in the liver. It participates in the activation of the immune system by coating antigens for work by the complement system. Levels correlate with cardiovascular events, and it is thought that atheromas activate the immune system, but CRP is not a specific test for atheromatous disease. Can only be used as a predictor