Rheumatoid Arthritis Flashcards
what is RA
autoimmune condition that causes chronic inflammation in the synovial lining of the joints, tendon sheaths and bursa
what does RA tend to affect
multiple small joint symetrically across both sides of the body - symmetrical polyarthritis
what are risk factors of RA
F>M
smoking
obesity
FHx
what is the most common gene associated with RA
HLA-DR4
What antibodies are associated with RA
- Fc portion of IgG (RF)
- anti citrullinated cyclic peptide (anti-CCP)
What is the pathophysiology of RA
- citrullination of self antigens which are then recognised by T&B cells that produce antibodies (RF and anti-CCP)
- stimulated macrophages and fibroblasts release TNFa
- inflamm cascade —> proliferation of synoviocytes which results in the typical ‘boggy’ joint swelling
- these grow over the cartilage and lead to restriction of nutrients and cartilage is damaged
- activated macrophages stimulate osteoclast differentiation contributing to bone damage
What are features of a typical history of RA
- hx > 6 weeks
- morning stiffness > 30 mins
- commonly c/o fatigue or malaise
What may be present O/E in RA
- soft tissue swelling and tenderness first
- ulnar deviation/palmar subluxation of MCPs
- swan-neck & Boutonnière deformity
- rheumatoid nodules on elbow
- check median nerve - carpal tunnel association
Give 5 relevant investigations into RA and state their findings
- RF & anti-CCP antibodies
- FBC - normocytic anemia
- WCC if concerned re septic arthritis
- inflamm markers
- X-ray changes apparent in established but need USS/MRI for early disease
What are 5 treatment options for RA
- initially DMARD monotherapy e.g. methotrexate but consider combo DMARDs
- steroids acutely - PO/IM or intra-articular
- symptom control w NSAIDs + PPI cover if no contraindications
- if diseases persists, consider biologics e.g. anti-TNF
- non drug: OT/PT, podiatry, psychological
What type of patients do extra-articular manifestations of RA normally present in
RF + patients with severe articular disease
What are extra-articular manifestations of RA
- 3Cs – Carpal tunnel syndrome, elevated Cardiac risk (CVD), Cord compression (due to atlanto- axial subluxation)
- 3As – Anaemia (normochromic & normocytic), Amyloidosis (very rare now due to improved treatment, can cause nephrotic syndrome and CKD), Arteritis (rare now due to improved treatment, can cause nail fold infarcts, cutaneous vasculitis & mononeuritis multiplex)
- 3Ps – Pericarditis (uncommon), Pleural disease (common), Pulmonary disease (common) e.g. bronchiectasis, bronchiolitis obliterans, fibrosis
- 3Ss – Sjögren’s (common), Scleritis/episcleritis (uncommon), Splenic enlargement (together with neutropaenia = Felty’s syndrome, rare)
What is HLA-B27 and what is it associated with
Class 1 surface antigen found in around 10% of white people
- associated with ankylosing spondylitis, iritis and juvenile arthritis
What might polarised light microscopy reveal in gout and pseudo-gout
- gout: negatively birefringent needle shaped crystals
- pseudo-gout: positively birefringement rhomboid shaped crystals
What are the adverse effects of methotrexate
- nausea most common
- oral ulcers, hair thinning
- hepatitis, cirrhosis
- pneumonitis
- bone marrow suppression
