ANA Flashcards
Is ANA a good screening test for patients with vague symptoms?
No: can be positive in sick individuals with non immune disorders and in some healthy individuals
procedure of ANA
Patient serum diluted and dropped onto HEp-2 slides
incubated, washed, 2* Ab added w/ fluorescent tag
slide read using a FA scope
titers less than what should be considered negative in an ANA test
less than 1:40
homogenous pattern ANA testing
anti-nDNA, anti-histones
seen in SLE
peripheral or rim pattern ANA testing
anti-dsDNA
SLE, Sjogren’s, MCTD
speckled pattern ANA testing
anti-ENA, anti-RNP
Raynaud’s, RA, Sjogrens, systemic sclerosis (Scleroderma)
nucleolar pattern ANA testing
anti-nRNA
Scleroderma, Sjogrens, SLE
Centromeric pattern ANA testing
CREST variant of systemic sclerosis (Scleroderma)
anti-centromere
in what disease should you continue a work up even if the ANA is negative?
Sjogren’s syndrome
besides a rising anti-dsDNA titer what other lab test can help predict an upcoming SLE flare?
falling C3 and C4 levels
SLE incorporate C’ components lowering free C’ in serum
what is the single greatest risk factor for SLE?
Female gender
what 2 antibodies are the most specific for SLE
Anti-dsDNA and anti-Smith
why do SLE patients test falsely positive on RPR and VDRL tests?
syphilis tests use particles coated w/ phospholipids
SLE patients who make anti-phospholipid Ab will make the test look like it’s postive
what specific autoantibody is characteristic of drud induced lupus?
anit-histone (H2A-H2B dimer)
a lupus like syndrome occurs when patients are on certain medications including cardiac drug procainamide
what is the major autoantibody in CREST syndrome of scleroderma?
anti- centromere
