224 - Rheumatoid Arthritis Flashcards
define rheumatoid arthritis?
chronic systemic inflammatory disorder that is autoimmune in nature, attacks synovial joints with pannus formation and extra articular manifestations (lungs/pleura, pericardium, sclera, subcut tissue)
what are the 7 features of the ACR scoring system and how many are required for an RA diagnosis?
4 of morning stiffness, swelling in 3 or more joints, swelling of hand joints, symmetrical joint swelling, erosions on hand in xray, rheumatoid nodules, abnormal serum rheumatoid factor
who does RA tend to affect and what causes it?
35-45 y/o F:M 3:1 genetic factors (HLA-DR4 and PTPN 22), non genetic factors (infections) and smoking
what causes inflammation in RA?
abnormal proliferation and activity of T cells, fibroblasts, osteoclasts, neutrophils and Bcells proliferate and produce Rheumatoid Factors (autoantibodies). This leads to abnormal production of cytokines and inflammatory mediators (TNF-alpha, IL-6, IL-8) causing acute phase response and liver produces CRP (acute phase reactants)
what is a pannus formation?
membrane of granulation tissue composed of synovium and bone marrow derived cells. Stimulates cytokine production and immune cell infiltration (macrophages, T and B lymphocytes) leading to cartilage, bone and ligament damage. Synovium also fills with neutrophils.
How does RA usually present (not systemic features)?
gradually starting small peripheral joints.
- articular features - pain, stiffness, synovitis, joint effusion, restriction of movement, deformity (swan neck and ulnar deviation)
- tendon rupture and contractures (tendons pull joints out)
- constitutional symptoms (fever, fatigue, weight loss)
- rheumatoid nodules in RF+ve - on pressure areas overlying bone. Subcut, firm non tender. Due to small cell vasculitis - shell of fibrous tissue surrounding fibroid centre)
how can RA present systemically?
- Rheumatoid vasculitis - occlusion and ischaemia
- Pulmonary effusions, nodules, fibrosis, cryptogenic organising pneumonia
- pericarditis and pericaridal effusions, valvular disease
- *keratoconjunctivitis sicca, (epi)scleritis, scelromalaecia
- entrapment neuropathies, mononeuritis multiplex
- anaemia, felty’s syndrome (RA +splenomegaly+leukopaenia)
- amyloidosis (incr. serum amyloid A protein levels) in organs
what investigations should be carried out to investigate for RA?
- inflammatory markers ESR and CRP
- Anti-CCP (cyclic citrillunated peptide) - predicts onset
- Rheumatoid Factor (80%)
- x-ray for erosions
- USS/MRI for synovitis
- CXR for pulmonary symptoms
what drugs can be prescribed in RF?
- analgesia
- NSAIDs
- steroids
- DMARDS (disease modifying anti-rheumatic drugs) best in combination
- methotrexate (Tcell inhibitor and purine metabolism inhibitor)
- sulfasalazine (5-ASA compound supresses TNF and IL-1 and inhibits immune cells
- Leflunomide (inhibits pyrrimidine synthesis and th. lymphocyte proliferation
- Biologic agents - anti TNF agents
- monoclonal antibodies (infliximab, adalimumab)
- soluble receptor proteins (etanercept)
what is vasculitis?
inflammation and necrosis of a blood vessel with impairment of circulation and damage to vessel integrity
what causes vasculitis?
immune cell infiltration into vessel wall esp. neutrophils. Causes fibrinoid necrosis of tissue and leukocytoclasis (WBC destruction). This causes endothelial damage, thrombosis, occlusion of vessel and vessel perforation and haemorrhage
how might vasculitis present?
- palpable purpura
- livedo reticularis (mottled purple discolouration of legs)
- ulcers or digital infarction
- urticaria
what investigations should be carried out for suspected vasculitis?
- tissue biopsy is gold standard
- angiogram
- inflammatory markers CRP and ESR
- FBC for anaemia, ↑WCC, eosinophilia
what is the most common vasculitis and who does it affect?
Giant Cell Arteritis (Temporal artertis). Affects >55s and more women by 3:1
what are the signs/symptoms of giant cell arteritis and how would you treat?
*jaw claudication
*localised headache
*constitutional symptoms (fever, fatigue, anorexia)
*temporal artery enlargement and tenderness
*may lead to blindness
treat with high does prednisolone