Immunological Testing Flashcards
what is immunology self reactivity?
breakdown of self-tolerance
What are the factors influencing autoimmunity?
genetic factors, age, exogenous factors
How is autoimmunity produced?
Organ specific or non-organ specific
Describe the pathophys for organic specific autoimmunity
antibodies are directed at a single target organ. Form immune complexes that deposit in tissues and activate complement system which leads to inflammation. Causes tissue damage, lesion deposits in target organ, and tendency toward cancer development in target organ.
Describe the pathophys for non organic specific autoimmunity
produce antibodies to nuclear or cytoplasmic antigen. form immune-complexes that deposit in tissues and form lesions. They activate complement system which leads to inflammation.
what is sle?
chronic systemic inflammatory autoimmune disease that beings in young adulthood and is more common in women (10:1). It affects AA and hispanics more than whites.
What are the symptoms of SLE?
arthritis, maialse, fever, weight loss, maculopapular rash, glomerluonephritis, nephritis, renal failure, alopeciea, anemia, purapura
What is the screen for SLE?
ANA= antinuclear antibody screen. There are two methods present. IFA Hep-2 (fluorescent) and EIA (no flurosence)
is ANA specific?
no, there is low diagnostic specificity because many of the antibodies associated with other autoimmune diseases. (2% of healthy persons test positive and 75% of elderly test positive)
What does a positive ANA indicate?
a nuclear antibody is present. it is not specific because many diseases are associated with positive ANA. around 75% of elderly people will test positive.
What is considered a “normal” titer for ANA
<1:40.
Follow up testing for ANA…if original ANA was positive, and the titer was negative then what does that mean?
either no disease, in treatment, or in remission
If the ANA titer is positive, then what additional follow up testing should you do?
Anti-dsDNA
Anti-histone
Anti-Sm
Anti-dsDNA
if this is positive, there is a high indication that this is SLE
Anti-histone is most often positive with…
drug induced lupus
If Anti-sm if involved, then they are more likely to have what?
renal involvement.
What is drug induced lupus?
a syndrome where SLE-like symptoms and antinuclear antibodies appear in patients taking certain drugs like procainamide, phenytoin, hydrazine, isoniazid. Patients will show rapid improvement once the drug is removed.
What is RA?
chronic inflammatory autoimmune disease. It primarily affects joints leading to cartilage destruction and periarticular erosions into bone. Associated with multiple organ involvement in some patients: soft tissue, heart valves, myocardium, lungs and spleen.
What is the pathophys for RA?
Immune complex deposits, leading to inflammatory activity in joints, loss of function, destruction, disability, deformity. Disease progression varies, with spontaneous remissions. mainly affects women
What are the symptoms of RA?
malaise, fever, weight loss, joint pain, stiffness develops after periods of inactivity
What is rheumatoid factor?
Autoantibody (most often IgM) that binds to Fc region of IgG.
How will you screen for RA?
RF tests. Do a quantitate RF if test is negative.
Does a positive RF confirm RA? Does a negative test r/o RA?
no to both
How is disease progression monitored?
with ESR and CRP
