Autoimmune Markers Flashcards
ANA
anti-nuclear antibody
RF
rheumatoid factor
CRP
C-reactive protein
ESR
erythrocyte sedementary rate
CTD
connective tissue disorder
why would you order an ANA?
- to exclude disorders in pts with uncertain clinical findings
- establish diagnosis in pt suspected of having autoimmune or CTD
- subclassify pt with established diagnosis of autoimmune or CTD (not always)
- monitor disease activity
ANA titer results
1:40 is negative results (some say 1:80)
what is the mechanism of the ANA?
a group of protein antibodies that react against cellular nuclear material
which disorder is ANA primarily used to diagnose?
SLE and other CTD
ANA homogenous pattern
shown in SLE, MCTD
ANA speckled patter
shown in SLE, scheloderma RA MCTD Sjorgen
ANA nucleolar pattern
shown in scleroderma
polymyositis
ANA outline pattern
shown in SLE
negative RF value
<60 u/mL
when would you order RF?
pt suspected of having RA
positive in 70-80% of people with established RA
sensitivity is low early on in the disease (only 50%)
C-reactive protein
non-specific indicator of inlammation
acute-phase reactant protein
when is the CRP elevated?
inflammation
tissue necrosis
why is CRP a good test to order?
- more sensitive and faster response than ESR
- may want to identify acute v chronic
- monitor disease process (how are they responding to treatment?)
ESR
measures acute and chronic infection, inflammation, neoplasm, tissue necrosis
-measures the rate at which RBCs settle in saline solution
why would you use a ESR?
can be used to monitor disease therapy
slower test
ACA
anticardiolipin antibody
-used to identify SLE (40% of SLE pts have it)
What are the clinical features of SLE?
- venous and arterial thrombosis
- neuropsychiatric disorder
- recurrent spontaneous abortion
- CVA
- thrombocytopenia
the ACA positively identifies SLE in how many percent of people?
40%
the presence of ACA indicates a SLE patient may be at greater risk for developing
antiphospholipid syndrome
anticentromere antibody
a form of ANA
- used to diagnose CREST sydrome
- differntiates schleroderm and CREST
when is anticentromere antibody test used?
pt suspected of having CREST syndrome (variant of schleroderma)
**not a marker of disease prognosis
antichromatin antibody (anti-NCS)
100% sensitive
97% specific for SLE
anticyclic-citrullinated peptide antibody (CCP IgC, anti-CCP)
used to diagnose RA (especially if RF is negative)
highly specific to RA (especially early on)
***marker for disease progression
anti-DNA antibody (anti ds DNA)
subtype of ANA
why order anti-DNA antibody?
65-80% sensitive with active SLE
anti-extractable nuclear antigen (anti-ENA)
also contains
anti-Jo-1
anti-RNP
anti-Smith
anti-Smith tells you what?
present in 30% of pts with SLE, but not present with other RA disorders
anti-RNP tells you what?
100% of pt with MCTD have it
anti-Jo-1 tells you what?
autoimmune interstitial pulmonary fibrosis
specific
antimitochondrial antibodies (AMA)
94% with biliary cirrhosis
liver biopsy is then performed (has to have tissue confirmation)
antineutrophil cytoplasmis antibody (ANCA)
usually elevated with UC, Wegener’s glanulomatosis (WG), PSC (primary sclerosing colangitis)
why use ANCA?
follow therapy in UC
what are the two patterns of staining with the ANCA?
P-ANCA perinuclear (MPO-ANCA)
C-ANCA cytoplasmic (PR3-ANCA)
antiscleroderma antibody (Scl-70 antibody)
diagnoses scleroderma (PSS) (45% pt test positive) fairly specific for PSS, but also seen in SLE, Sjorgen, RA
antismooth muscle antibody (ASMA)
used to diagnose autoimmune chronic active hepatitis
when would you order ASMA?
70-80% of pts with CAH (chronic active hepatitis)
positive titer for ASMA is
> 1:160
Sjogren antibodies
ANA with subtypes
A (RO)
B (La)
C
