LO: Discuss the basic epidemiology, pathophysiology, presentation, investigation, management, complications and prognosis of rheumatoid arthritis

Epidemiology

• Incidence 1.5 men and 3.6 women/10,000 people per year
• Female to male ratio $\approx$ 3:1
• Incidence peaks in 50s
• First degree relatives 2-3x increased risk

Presentation

• Stiffness
  • Morning, inactivity, prolonged (>1 hour) - inflammatory
  • Less than 1 hour, joint locking - non-inflammatory
• Effect of activity
  • Improved - inflammatory
  • Worse - non-inflammatory
• Erythema
  • Present during flare - inflammatory
  • Nah - non-inflammatory
• Swelling
  • Flare, boggy swelling - inflammatory
  • Bony swelling - non-inflammatory
• Constitutional disturbance
  • Weight loss, fatigue, night sweats - inflammatory
  • No - non-inflammatory
• Extra-articular features
  • Yes - inflammatory
  • No - non-inflammatory

Rheumatoid pattern

• Distal interphalangeal joint (DIPj) sparing
• Metacarpophalangeal joint (MCPj) swelling
• Symmetrical changes
• Loss of skin crease definition

Chronic deformity

Ulnar deviation

• Chronic synovitis - destroys synovial lining of MCPj
• Ligament and capsule damage
• Tendon slippage
• Wrist imbalance
• Voluntary pinch forces

Swan neck deformities

• Imbalance of muscle forces on the proximal interphalangeal (PIP) caused by weakening of any of the stabilising collateral ligaments
• Hyperextension of the PIP joint
• Flexion of the DIP joint

Boutonniere deformities

• Central slip of the extensor tendon stretched or tears
• Lateral bands of the extensor mechanism slip downward toward the palm
• Shifts forces, forcing the middle joint into permanent flexion - pulling the tip joint into hyperextension

Z thumb

• Carpometacarpal joint subluxation
• Metacarpophalangeal flexion
• Interphalangeal hyperextension

Investigations

• Full blood count - anaemia, thrombocytosis
• Raised inflammatory markers - CRP/ESR
• Baseline urea and electrolytes (U&E) and liver function tests (LFT) - low albumin/raised ALP
• Serology - rheumatoid factor (RhF), anti-CCP
• Virology/microbiology - infective trigger

Imaging

• X-ray hands and feet and other involved joints
  • Erosive disease
• Joint space narrowing
• Marginal erosions
• Accelerated osteoarthritis
• Juxta-articular osteopenia
• Ultrasound/MRI - looking for subclinical synovitis

Classification criteria

• EULAR/ACR 2010
• $\ge$ 6 = definite rheumatoid arthitis
• < 6
  • Does not have to be concomitant
  • Prospective - may still require follow-up and observation

Pulmonary complications

• Pneumonitis
• Pleuritis and effusion
• Fibrosis
• Nodules
• Pneumoconiosis
• Obstructive lung disease

Osteoporosis

• Rheumatoid arthritis a risk factor for osteoporosis
• Systemic inflammation - increased expression of growth factors
• Older age, disability/reduced weight bearing, low body mass

Haematological complications

• Felty's syndrome
  • Splenomegaly (enlarged spleen)
  • Anaemia (low haemoglobin)
  • Neutropenia (low white cell count)
  • Thrombocytopenia (low platlets)
  • Arthritis

Ocular complications

• Sicca - Schirmer's test positive if <5mm in 5 minutes
• Episcleritis - painless red eye without vision loss or frank discharge
• Scleromalacia perforans - granulomatous scleral resorption
• Corneal melt - prelude to the development of corneal perforation

Complications

• Vasculitis
• Neurological dysfunction
• Cardiovascular disease

Treat to target approach

• High disease activity is associated with more radiological damage and worse functional outcomes this is seen across multiple differnt composite indices of disease activity
• Improved outcomes even with remission over low disease activity

DAS-28

• ESR/CRP
• VAS (pain, score out of 100)
• Tender joint count
• Swollen joint count
• Remission - <2.6
• Low - 2.6-3.2
• Moderate - 3.2-5.1
• High - >5.1

Treatment pathway

1. cDMARD (conventional disease modifying anti-rheumatic drugs) monotherapy
2. Trial other cDMARD
3. bDMARDs

LO: Describe the role of the MDT and the concept of shared care in the management of RA

Multidisciplinary team (MDT)

Clinical nurse specialists

• Disease and drug education
• Empowering patients to take responsibility for their disease
• Encouraging self-management
• Signposting to any physical or financial support
• Annual review

Occupational therapy

• Alternative ways of doing tasks
• Home visits
• Corrective splinting

Physiotherapy

• Disease activity scores
• Exercise programmes
• Promote self-management
• Wax therapy, hydrotherapy, ultrasound, acupuncture

Podiatry/biomechanics

• Most had foot symptoms (82%)
• Foot deformities
• Common sites for ulceration
• Loss of fat pads result in callouses
• Referral to podiatry, gait analysis, special shoes, insoles

Surgery

• Joint replacement surgery
• Tendon repairs
• Fusion, replacements
• Synovectomy: common orthopaedic procedure in the past, rarely seen now

LO: Describe the commonly used drugs to treat rheumatoid arthritis

Methotrexate

• Anchor DMARD - first line of defence
• Oral or SC (epipen looking thingies) - ONCE WEEKLY
• Co-prescription - folic acid 5mb, 1-7x/week
• Contraindications - trimethoprim, eGFR<30
• Side effects - gastrointestinal disturbance, bone marrow suppression, cirrhosis (liver issues), pneumonitis (first 6-12 months), interstitial lung disease (unlikely)

Other DMARDs

Sulfasalazine

• 2nd line DMARD
• 1st in certain groups
• Safe in pregnancy/breast-feeding

Hydroxychloroquine

• Risk of retinal toxicity with cumulative use
• Safe in pregnancy/breast-feeding
• Contraindication - tamoxifen

Leflunomide

• Risk of hypertension
• Teratogenic (no pregnancy for 2 years post use or cholestyramine washout)

LO: Describe the efficacy, safety, suitability and mechanism of action of DMARDs and Biologics in the treatment of rheumatoid arthritis

Biologics

• Anti-TNF - RA, PsA, axial spondyloarthritis (axSpA)
  • Adalimumab, certolixumab, etanercept, infliximab
• B-cell depletion - RA, small vessel vasculitis (SVV)
  • Rituimab
• IL-6 inhibition - RA, Giant cell arteritis (GCA)
  • Tocilizumab
• Selective co-stimulation modulators - RA
  • Abatacept
• IL-1 inhibition - Gout, auto-inflammatory
  • Anakinra
• IL-17 inhibition - PsA, axSpA
  • Secukinumab, ixekizumab, bimekizumab
• IL-23 inhibition - PsA
  • Guselkumab, Ustekinumab (dual IL-12i)
• IL-5 inhibition - eosinophilic granulomatosis with polyangiitis (eGPA)
  • Mepolizumab
• Conventional synthetic csDMARDs - JAK inhibitors

Biosimilars

• Made from living sources
• Require a specialised process to produce
• Very similar, but not identical to original biologics
• Faster development process using public information from original biologic approval
• Less expensive than original biologics

Immunosuppression

• Hold during infections
• Avoid live vaccines
• Surgery - cDMARDs should not routinely be stopped in the perioperative period, bDMARDs are held
• No bloods, no prescription
• DMARDs initiated by secondary care but then most continued in primary care under a 'shared care agreement'