Lecture 14: Labs In Rheumatogolic Disease Flashcards
What is ESR? What is its purpose? What conditions have elevated ESR?
ESR = erythrocyte sedimentation rate (d/t rouleaux formation)
Tests for inflammation; non-specific
Pregnancy, infection, rheumatic fever, MI, nephrons is, acute hepatitis, TB, hypo- and hyperthyroidism
{decreased RBCs in anemia = +ESR//increased RBCs in polycythemia and hyperviscosity syndrome = -ESR}
What is CRP?
Compare to ESR is it nonspecific or specific?
What is its purpose?
What is a normal CRP level?
CRP is a direct measure of _______ ______ _______ .
-CRP is C-reactive protein; an annular protein synthesized by the liver that binds to lysophosphatidylcholine which is expressed on the surface of dead/dying cells to activate complement system via C1
-CSR is more specific than ESR, (bc it is not affected by hormones, RBC mass, anemia/polycythemia) it also rises earlier
-CSR is used to detect infection, assess severity of inflammatory disease, detect MI, and screen for disease
-Normal CRP is <8 mg/L
-CRP is a direct measure of acute phase response. (ESR is the indirect way).
What is ANCA?
What conditions is ANCA high in?
What ways can ANCA be tested?
What is c-ANCA vs p-ANCA?
Anti-neutrophil cytoplasmic antibodies
ANCA is seen in vasculitities, which are characterized by granulomatous formation and inflammation of vessels then rupture then hemorrhage or occlusion
ANCA can be tested using indirect immunofluorescence assay or ELISA
c-ANCA is IgG against proteinase 3 in cytoplasm
p-ANCA is IgG against myeloperoxidase around the nucleus
What is ANA?
What is the purpose of ANA?
What is the first step in testing autoimmune disease?
What is the antibody(ies) in SLE?
Antibody in Sleroderma?
Antibody in Sjogren’s?
Anti-nuclear antibodies that bind to cellular components in the nucleus
ANA is used to diagnose SLE, SS, and myositis
First step for testing autoimmune dz is screening which is what ANA does
—SLE —> anti-dsDNA and anti-Sm
————ANA has high sensitivity for SLE!
—Scleroderma —> anti-Scl-70 (topoisomerases I)
—Sjogren’s —> anti-Ro and anti-La
What is RF?
Relationship to Rheumatoid Arthritis?
What is normal RF levels?
Causes of elevated RF?
Rheumatoid factor
(not specific to RA tho)
Normal RF levels are 0-20. A higher RF means poorer prognosis
-DM, CA, Bacterial Endocarditis, Aging, Vaccines
What is ACPA?
Compare to RF?
Is ACPA used to monitor disease?
ACPA = anti-cyclic citrullinated peptide
Antibodies against citrullinated arginine residues
more specific (97%) than RF for diagnosing RA. Like if ACPA is positive, I’m thinking RA!!
No, bc once confirmed, RF and ACPA do not need to be tested again to monitor disease
What is complement?
What is its relation to autoimmune disease?
What happens if there is a deficiency in one of the components of complement?
Part of the innate immune defense against microorganisms
3 pathways that all result in C5 cleavage —> MAC
classic: triggered by Ab:Ag complex
alternative: triggered by C3 hydrolysis
lectin: triggered by MBL:Mannose complex
Autoimmune disease often involves uninhibited complement activation
Infections with N.Meningitidis and N.gonorrhoeae are associated with deficiencies in the MAC component of compliment!
What is p-ANCA associated with?
What is c-ANCA associated with?
P-ANCA = MPO —> a/w eGPA, MPA, UC and PSC
C-ANCA = PR3 —> a/w GPA
Which complement pathway is preferentially involved in Lupus and which is in RA?
Lupus = classical complement
RA = Alternative complement
!!
What are some examples of consequence of complement deficiency?
Most pyogenic infections
Like
Meningitis, Cystitis, and Impetigo
