Immunology - Autoimmune Disorders Flashcards
(229 cards)
what type of HS is SLE?
type III
Why is C3/C4 low in SLE?
Ab-Ag complexes activate complement
supply < demand => hypocomplementemia
what antibodies cause lupus?
anti-nuclear antibodies (ANA’s)
anti-double stranded DNA (anti-dsDNA)
anti-smith (anti-Sm)
ANA is present in the serum of _____ patients and in __% of normal patients
lupus
5
Is ANA sensitive or specific?
sensitive, meaning a negative result indicates the disease is very unlikely
why isn’t ANA specific for lupus?
because it is found in many other autoimmune disorders
what is considered a normal ANA?
< 1:160
what 2 antibodies are specific for SLE?
anti-dsDNA anti-Sm
what Ab can be used to monitor disease activity in SLE?
anti-dsDNA will increase during flares
what Ab is associated with renal involvement in SLE?
anti-dsDNA = glomerulonephritis
what is anti-Sm directed against?
small nuclear ribonucleoproteins (snRNPs)
what are snRNPs?
small nuclear ribonucleoproteins made up of RNA and protein combine with RNA transcripts –> form a spliceosome –> removes a portion of the RNA transcript
what are RNA transcripts?
pieces of RNA that have been synthesized from DNA
what are snRNPs used for?
modify RNA before it is translated into a protein
antibodies against snRNPs are seen in what?
SLE
anti-Sm antibodies are directed against what?
snRNPs
what is an ENA panel?
extractable nuclear antigens panel of blood tests against nuclear antigens
when would you order an ENA panel?
if you suspect an autoimmune disease
what antibodies are tested for on an ENA panel?
Anti-RNP Anti-Sm Anti-SS-A (Ro) Anti-SS-B (La) Scl-70 Anti-Jo-1
anti-RNP
MCTD SLE scleroderma
anti-Sm
specific for lupus
anti-SS-A (Ro)
Sjogren’s syndrome SLE scleroderma
anti-SS-B (La)
Sjogren’s syndrome SLE scleroderma
scl-70
specific for scleroderma