Rheumatology Flashcards
when should joint aspiration not be done?
if skin infection is suspected
what should normal synovial fluid look like?
clear and colorless
An inflammatory process of 1 or 2 joints indicates … (2)
septic
crystals
An inflammatory process of multiple joints indicates … (1)
rheumatoid arthritis
A non-inflammatory process of 1 or 2 joints indicates … (2)
osteoarthritis
trauma
A non-inflammatory process of multiple joints indicates … (1)
osteoarthritis
A non articular process of 1 or 2 joints indicates … (2)
bursitis
tendonitis
A non-articular process of multiple joints indicates … (1)
fibromyalgia
which 2 tests should we start with when suspecting a rheumatologic problem?
erythrocyte sedimentation rate (ESR)
C-reactive protein (CRP)
what do elevated levels of ESR indicate?
inflammation
what does the ESR test measure?
how quickly RBCs fall to the bottom of tube in 1 hour
a plasma protein produced by the liver that is active in the complement pathway and cellular immune response
c-reactive protein
what does an elevated CRP indicate?
significant inflammatory process
what is the high-sensitivity CRP used for?
cardiovascular processes
what does rheumatoid factor look for?
antibodies against IgG
what is rheumatoid factor most commonly associated with?
rheumatoid arthritis
what do positive levels of rheumatoid factor indicate? (4)
autoimmune disorder
inflammatory disease
infection
cancer
what are RA patients with RF titers within the normal range called?
seronegative
which test finds autoantibodies against citrullinated proteins by binding to the amino acid citrulline?
anticitrullinated protein antibodies (ACPA)
which test, if positive, is a clinical feature of RA at 90-95% specificity?
ACPA (anticitrullinated protein antibodies)
Y-shaped proteins that recognize unique markers (antigens) on pathogens
immunoglobulins (antibodies)
immunoglobulin secreted into mucous, saliva, tears, and colostrum
IgA
immunoglobulin that is a B-cell receptor and stimulates release of IgM
IgD
immunoglobulin that binds to mast cells and basophils. Active during allergies and act as an antiparasitic
IgE
immunoglobulin that binds to phagocytes; is the main blood antibody for secondary responses and crosses the placenta
IgG
immunoglobulin that is the main antibody of primary responses. Acts as a B-cell receptor and is active in immune system memory
IgM
related to fluid accumulation around, not inside the joint space
non-articular
what are 3 misleading factors of an ESR?
pregnancy
menses
obesity
when should CRP be measured twice, 2 weeks apart and the values averaged?
when used in cardiovascular risk assessment
in what type of healthy patients could RF be falsely positive? (2)
older
smokers
which test is a predictor of RA in patients with undifferentiated arthritis?
ACPA
what is the management of a patient who tests positive in an anticitrullinated protein antibody?
aggressive treatment early + close follow-up to control systemic inflammation
5 rheumatic diseases that would give a positive RF
Sjogren syndrome
RA
Systemic Sclerosis
SLE
Mixed connective tissue disease
5 non-rhematic conditions that would give a positive RF
mononucleosis
hepatitis
malaria/TB
subacute bacterial endocarditis
chemo/radiation
heterogenous autoantibodies directed against cellular nucleic acids and nucleoproteins
antinuclear antibodies
when is ANA not suitable as a screening test?
if asymptomatic
a high ANA level is suspicious for what?
autoimmune disorder
type of ANA antibody that is specific for SLE; rises when disease flares, falls when it subsides, and is helpful in disease management
Double-stranded DNA (Anti-dsDNA)
type of ANA antibody that is specific for SLE and titers remain positive after disease has subsided and other antibodies have normalized, making it a useful diagnostic tool
Smith (Anti-Sm)
type of ANA antibody that targets the protein portion of nucleosomes in DNA and is present in all cases of drug-induced lupus
nucleosome (anti-histone)
type of ANA antibody that strongly supports the diagnosis of Sjogren if positive
Anti-Ro/SSA and Anti-La/SSB
autoantibodies directed against neutrophil cytoplasmic antigens
antineutrophil cytoplasmic antibodies (ANCAs)
a positive antineutrophil cytoplasmic antibody (ANCA) indicates what disease process?
vasculitic syndromes
test that measures the amount of complement proteins (C1-C9) in the blood and their activity to identify and fight off disease
complement (C3 & C4)
which is the most abundant complement protein?
C3
which compliment protein is more sensitive and specific to smaller changes?
C4
what levels of complement (C3 & C4) proteins reflect an inflammatory process like cancer, viral infection, non-alcoholic liver disease, obesity, diabetes, heart disease, and autoimmunity?
high levels
what levels of complement (C3 & C4) proteins reflect systemic lupus erythematosus, rheumatoid arthritis, or alcoholic liver disease?
low levels
why does complement depletion occur?
due to activation of the immune system
antigen on the surface of WBCs encoded by the B locus - helps to differentiate self from foreign material
human leukocyte antigen B27
what does a positive result in human leukocyte antigen B27 indicate? (3)
ankylosing spondylitis
reiter syndrome
anterior uveitis
what does it mean when an asymptomatic patient tests positive for human leukocyte antigen B27, but does NOT have any family history?
not clinically significant
