Rheumatoid Arthritis Flashcards
Rheumatoid arthritis: presentation
swollen, painful joints in hands and feet
stiffness worse in the morning
gradually gets worse with larger joints becoming involved
presentation usually insidiously develops over a few months
positive ‘squeeze test’ - discomfort on squeezing across the metacarpal or metatarsal joints
deformities in late features of rheumatoid arthritis
Swan neck and boutonnière deformities
unlikely to be present in a recently diagnosed patient.
Unusual presentation of RA?
acute onset with marked systemic disturbance
relapsing/remitting monoarthritis of different large joints (palindromic rheumatism)
NICE have stated that clinical diagnosis is more important than criteria such as those defined by the American College of Rheumatology.
true
2010 American College of Rheumatology criteria
Target population. Patients who
1) have at least 1 joint with definite clinical synovitis
2) with the synovitis not better explained by another disease
Classification criteria for rheumatoid arthritis (add score of categories A-D;
a score of 6/10 is needed definite rheumatoid arthritis)
2010 American College of Rheumatology criteria what factors does it look at?
Joint involvement: 1 large joint 0 2 - 10 large joints 1 1 - 3 small joints (with or without involvement of large joints) 2 4 - 10 small joints (with or without involvement of large joints) 3 10 joints (at least 1 small joint) 5
Serology:
Negative RF and negative ACPA 0
Low-positive RF or low-positive ACPA 2
High-positive RF or high-positive ACPA 3
Acute phase reactants:
Normal CRP and normal ESR 0
Abnormal CRP or abnormal ESR 1
Duration of symptoms:
< 6 weeks 0
> 6 weeks 1
What is RF?
Rheumatoid factor (RF) is a circulating antibody (usually IgM) which reacts with the Fc portion of the patients own IgG.
RF can be detected by either
Rose-Waaler test: sheep red cell agglutination
Latex agglutination test (less specific)
RF is positive in ?% of patients
RF is positive in 70-80% of patients
high titre levels of RF are associated with severe progressive disease
true
high titre levels of RF are a marker of disease activity
false
Other conditions associated with a positive RF include:
Felty's syndrome (around 100%) Sjogren's syndrome (around 50%) infective endocarditis (around 50%) SLE (= 20-30%) systemic sclerosis (= 30%)
What % of general population have +ve RF
general population (= 5%)
RF is commonly +ve in TB, HBV, EBV, leprosy
False
rarely +ve
Anti-cyclic citrullinated peptide antibody may be detectable up to 10 years before the development of rheumatoid arthritis
true
Anti-CCP is more specific for RA than RF
true
much higher specificity of 90-95%.
Anti-CCP is more sensitive for RA than RF
false
sensitivity similar to rheumatoid factor (around 70%)
NICE recommends that patients with suspected rheumatoid arthritis who are rheumatoid factor negative should be test for anti-CCP antibodies.
true
Rheumatoid arthritis: x-ray changes - early
loss of joint space
juxta-articular osteoporosis
soft-tissue swelling
Rheumatoid arthritis: x-ray changes - late
periarticular erosions
subluxation
A number of features have been shown to predict a poor prognosis in patients with rheumatoid arthritis:
rheumatoid factor positive anti-CCP antibodies poor functional status at presentation HLA DR4 extra articular features e.g. nodules insidious onset
What X ray features have poor prognosis?
X-ray: early erosions (e.g. after < 2 years)
