Rheumatoid arthritis Flashcards
What is rheumatoid arthritis?
an autoimmune condition that causes chronic inflammation in the synovial lining of joints, tendon sheaths and bursa
Describe the typical distribution of RA across the body
typically affects multiple small joins symmetrically across both sides of the body (symmetrical polyarthritis)
Give 4 risk factors for RA:
1) female sex
2) smoking
3) obesity
4) family history
What is the most common gene associated with RA?
HLA DR4
Name two autoantibodies associated with RA:
1) Rheumatoid factor (RF)
2) Anti-cyclic citrullinated peptide antibodies (anti-CCP)
Describe the pathophysiology of rheumatoid factor in RA:
Rheumatoid factor targets the Fc portion of IgG causing an immune system response that results in systemic inflammation
Which are more sensitive and specific to RA testing, rheumatoid factor or anti-CCP autoantibodies?
anti-CCP autoantibodies
What are the 3 key presentations of RA?
1) pain
2) stiffness
3) swelling
Name the 4 most commonly affected joints in RA:
1) metacarpophalangeal joints
2) proximal interphalangeal joints
3) wrist
4) metatarsophalangeal joints
Give two findings found on palpation of a joint affected by RA:
1) tenderness
2) boggy synovial thickening
True or false: RA rarely affects the DIP joints
true (a good differentiating factor from OA)
What is palindromic rheumatism?
where patients have spontaneous episodes of joint pain, stiffness and swelling affecting only a few joints for a few days before completely resolving without treatment
Give 4 hand signs seen in advanced RA:
1) Z-shaped deformity of the thumb
2) Swan neck deformity
3) Boutonniere deformity
4) ulnar deviation of the fingers at the MCP joint
Describe a swan neck deformity:
hyperextension of the PIP joint and flexion at the DIP
Describe a boutonniere deformity:
hyperextension of DIP and flexion of PIP
What life threatening manifestation of RA affects the spine?
atlantoaxial subluxation
Describe how atlantoaxial subluxation can lead to a medical emergency: (2)
1) RA causes synovitis and damage to the ligaments around the odontoid peg of C2, allowing it to shift within C1
2) subluxation of this joint can compress the spinal cord
Give 4 extra-articular manifestations of RA:
1) Sjogren’s syndrome
2) Rheumatoid nodules
3) Anaemia of chronic disease
4) Felty’s syndrome
What are the two presentations seen in Sjogren’s syndrome?
dry eyes and dry mouth
What are rheumatoid nodules?
firm, painless lumps found on the hands and elbows
Name the three conditions seen in Felty’s syndrome:
1) RA
2) neutropenia
3) splenomegaly
Name 5 investigations that may be performed by a rheumatologists following RA referral:
1) rheumatoid factor blood test
2) anti-CCP blood test
3) inflammatory markers bloods (CRP, ERP)
4) X-rays for bone changes
5) CT/MRI (if findings are unclear)
Give 4 X-ray findings associated with RA:
1) periarticular osteopenia (weakened bone at the joint surfaces)
2) boney erosion
3) soft tissue swelling
4) joint destruction and deformity
What scoring system assesses 28 joints to monitor RA and treatment response?
The Disease Activity Score 28 Joints (DAS28)
What treatment can initially be used to relieve symptoms in RA whilst waiting to see a rheumatologist?
1) short term steroids
2) NSAIDs
What DMARD is given for mild RA/ palindromic rheumatism?
hydroxychloroquine
Give the 3 long-term DMARD treatment plans for RA:
1) monotherapy (methotrexate, lefunomide, sulfasazine)
2) combination therapy with multiple cDMARDs
3) biologic therapies with methotrexate
Name 4 cDMARDs:
1) azathioprine
2) ciclosporin
3) cyclophosphamide
4) mycophenolate
What does cDMARD stand for?
conventional disease modifying anti-rheumatc drugs
Give two biologics that inhibit TNF:
1) infliximab
2) adalimumab
What is the mechanism of rituximab?
monoclonal antibody against CD20 on B cells
Name 2 biologics that act to inhibit IL-6:
1) tocilizumab
2) sarilumab
Name 2 biologics that act to inhibit JAK:
1) Tofacitinib
2) upadactinib
Name a biologic that inhibits T cell continuation:
abatacept
Give 3 general side effects of biologic use:
1) immunosuppression
2) increased risk of certain cancers (e.g. shin)
3) reactivation of latent TB
Describe the mechanism of methotrexate:
inhibits folate production
True or false: methotrexate cannot be taken during pregnancy
true (folate interference)
Give 3 side effects of methotrexate:
1) bone marrow suppression
2) leukopenia
3) highly teratogenic
Give two side effects of leflunomide:
1) hypertension
2) peripheral neuropathy
Describe the mechanism of leflunomide:
interferes with the production of pyrimidine and so acts as an immunosuppressant
Give 2 side effects of sulfasalazine:
1) orange urine
2) reversible male infertility (low sperm count)
Describe the mechanism of hydroxychoroquine:
interferes with toll-like receptors, disrupting antigen presentation
Give 3 side effects of hydroxychloroquine:
1) retinal toxicity
2) hair bleaching
3) blue-grey skin pigmentation
