3rd year Rheumatology Lecture 3b Rheumatoid arthritis

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3rd year RheumatologyLecture 3(b)Rheumatoid
arthritis
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Introduction

• RA is a common chronic inflammatory joint
  condition
• multifactorial aetiology
• variable course with exacerbations and remissions
  of activity
• inflammation leads to joint damage (erosions)
• can result in severe disability

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History

• Rheumatoid first used in 1859 by Garrod
• Little evidence for RA prior to 16th Century
• Possibly earlier in New World
• In contrast to OA and Gout

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Epidemiology

• Incidence
• 1.4/10000 male, 3.6/10000 females
• Prevalence 0.5-2
• malefemale 13
• Worldwide distribution
• higher in native Americans
• absent in some parts of Africa
• Onset any age but maximum
• 40 - 70 years in women
• 60 - 70 years in men

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Genetic factors

• Small increased risk in siblings
• Monozygotic twins
• 15 concordance
• Dizygotic twins
• 4 concordance
• HLA DR4

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Clinical features

• Symmetrical deforming polyarthritis
• affects synovial lining of joints, bursae and
  tendons
• more then just joint disease
• Presentation
• Variable
• Gradual or acute/subacute
• Palindromic
• Monoarticular
• Symmetrical, diffuse small joint involvement

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Progression of joint involvement

• Spread occurs within months to years to other
  joints
• Almost any joint may be involved
• Spontaneous remission can occur (after acute
  onset)
• Poor prognosis factors exist
• Symptoms
• Of inflammation
• stiffness, pain, swelling, warmth, redness

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Pattern of joint involvement

• symmetrical
• small joints of hands - DIP spared
• characteristic features
• Boutonniere
• Swan neck
• Z thumb
• Volar subluxation
• Ulnar deviation

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Functional impairment

• related to underlying disease activity and
• joint damage due to previous activity

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Extra articular disease

• nodules
• eye
• lung
• kidney
• vasculitis
• nerves
• Feltys

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Investigations

• Haematology
• Hb, wcc, plts, ESR
• Biochemistry
• UE, LFT, CRP
• Immunology
• RhF, ANA
• Microbiology
• viral titres
• Radiology
• XR, bone scan, MRI

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Differential diagnosis

• Post viral (parvo, rubella)
• Reactive arthritis
• SLE
• Polyarticular Gout
• Polyarticular OA

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Diagnostic criteria

• ARA 1958
• 11 inclusion criteria
• 7 classical RA
• 5-6 definite RA
• 3-4 probable RA
• 20 exclusion criteria

• ACR 1987 (4/7 necessary)
• 1. Morning stiffness (gt 1 hour)
• 2. Arthritis of at least 3 areas (gt 6 weeks)
• 3. Arthritis of hand joints
• 4. Symmetrical arthritis
• 5. Rheumatoid nodules
• 6. Serum rheumatoid factor
• 7. Radiographic changes

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Management

• Education
• Physical therapies
• Drugs
• analgesics
• NSAIDs
• DMARDs
• Immunotherapies
• Steroids ia, po, im, iv
• Surgery

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Prognosis

• Life expectancy reduced by
• 7 years in men
• 3 years in women
• Severe morbidity
• sudden onset do better than gradual
• early knee involvement bad
• Bad RA has a worse prognosis than IHD or Hodgkins

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Pathology

• RA joint
• SM hyperaemic, congested
• synovial cell proliferation and villous
  hypertrophy
• SM infiltration by lymphocytes, macrophages
• Vascular pannus at cartilage-synovium junction
• increased volume and cellularity of SF
• atrophy of supporting muscles
• osteopaenia of surrounding bone

• Normal joint
• synovial membrane (macrophage and fibroblast-like
  cells)
• fibrous joint capsule
• synovial fluid
• cartilage covers articular surface

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Immunopathology

• Aggregates of T-cells, macrophages and plasma
  cells in SM
• Activated phenotype
• SF contains mainly neutrophils
• Pro (TNF?, IL1, IL6) and anti-inflammatory (IL10,
  TGF?) cytokines within joint
• Interplay between immune cells and cytokines
  generates inflammation and joint damage
• What initiates the process and why doesnt it
  resolve?