Rheumatoid Arthritis Flashcards
What is Rheumatoid Arthritis?
Chronic, symmetric, erosive synovitis of peripheral joints (wrists, MCPs, MTPs). Characterised by a number of extra articular features.
What is the pathophysiology of RA?
- Hypertrophy of synovial membrane
- Activated rheumatoid synovium (pannus) grows into andover the articular surface.
- Inflammatory mediators trigger release of MMPs and colalgenases
- Destruction of articular cartilage and subchondral bone
What are the theories explaining the relapsing remitting pattern of RA?
- Sequestered Ag
- Molecular mimicry
What is the sequestered antigen theory of relapsing remitting pattern of RA?
-During inflammation, immune complexes are deposited at avascular cartilage-bone junction; ICs are released as further cartilage breaks down –> inflammatory cascade.
What is the molecular mimicry theory of RA relapsing remitting?
Cartilage damage -> altered cartilage resembles undefined offending agent – > triggers inflammatory cascade.
Epidemiology of RA?
- 1% adults
- 3F:1M
- Onset 20-40
What are the genetic predispositions to RA?
-HLA-DR4/DR1 association
Joint involvement in RA?
Symmetric
Signs and symptoms of RA?
- Morning stiffness
- Joint swelling, tenderness
- Loss of motion, instability, deformity, crepitus
- Constitutional symptoms
- extra-articular features
- Complications of chronic synovitis
What are the complications of chronic synovitis?
- Signs of mechanical joint damage: dec ROM, instability, deformity, crepitus
- Joint deformities
- Atlanto-axial and subaxial subluxation
- Ruptured Baker’s cyst
What are the syndromes of RA?
- Sjogrens: keratoconjunctivitis sicca, xerostomia (dry eyes and mouth)
- Caplan’s: multiple pulmonary nodules and pneumoconiosis
- Felty’s: arthritis, splenomegaly, neutropenia
Poor prognostic factors in RA?
- Young age of onset
- High RF titre
- Elevated ESR
- Activity >20 joints
- Presence of EAF
Ix in RA work up?
- RF
- anti-CCP (cyclic citrullinated peptide)
- FBE
- ESR
- CRP
- Imaging: Xray / US for hands
Goals of RA therapy?
Remission or lowest possible disease activity:
- relieve pain and stiffness
- maintain function and lifestyle
- prevent or control joint damage
What is the RA window of opportunity?
Early treatment with DMARDs within first 3mo of disease may allow better control / remission
Behavioural / lifestyle treatments of RA?
- Exercise: isometrics, gentle ROM exercises during flares)
- Job modification if required
When should DMARDs be started?
As soon as possible
First line DMARD in RA?
Methotrexate; start asap unless CIx
Onset of action for methotrexate?
8-10weeks
What DMARDs can be added on to methotrexate therapy?
- Hydoxychloroquine
- Sulfasalazine
- Leflunomide
What are the biologic agents DMARDs?
- TNF Inhibitors: etanercept, adalimumab, inflixamab
- B cell inhibitor: rituximab
- Cell adhesion inhibitor: abatacept
- IL6 inhibitor: tocilixumab
Systemic corticosteroid use in RA?
-Low dose 5-10mg/d for short term improvement in symptoms if NSAIDs ineffective to bridge gap until DMARD effect
Considerations in initiating prolonged corticosteroid therapy?
- baseline DEXA scan
- consider bone supportive pharmacologic therapy if using >3mo at >7.5mg/day
What are the typical features of inflammatory joint pain?
- Acute or subacute pain
- May worsen quickly
- Better after movement
- Worse after rest
- Swelling often prominent
- Stiffness may last hours
- Usually worse in morning
