Rheumatoid Arthritis Flashcards
What joints are mainly affected by RA
Peripheral joints
e.g. MCP, PIP, wrists
NOT the DIP though as too small and not enough synovium
Has to be joints with sufficient synovium as this is what gets inflamed
Larger joints like elbow and shoulder can also be affected
RA is usually symmetrical - true or false
True
e.g. both hands would be affected
Also typically polyarticular - multiple joints
What is the main structure involved in RA
The synovium
Lies inside of a synovial joint capsule
Which joints in the body are synovium lined
Hand, wrists, shoulders, C1, C2, TMJ, hip, knees, feet (MTPs) and ankles
What is the main antibodies involved in RA
Rheumatoid factor
Anti-CCP (more specific)
Describe the inflammatory process in RA
The synovium gets inflamed and becomes a spongy mass with increased blood flow
This brings even more inflammatory cells to the area
If not treated it can stimulate osteoclasts which erode the bone leading to deformity
What is a pannus
Thickened synovium due to granulation tissue
Brought on by inflammation
How is early RA defined
Less than 2 years since symptoms started
What is the significance of the first 3 months of RA presentation
This is therapeutic window of opportunity
If you catch the disease and start treating it you can alter progression and make it less aggressive - prevent bone damage/erosions
How can you diagnose RA
History and examination are key Routine blood tests Inflammatory markers Autoantibody test - RF and anti-CCP Imaging
What results may you see in a FBC on someone with RA
Anaemia - due to chronic inflammation, bone marrow is under stress
Will be normochromic and normocytic
High platelets - non-specific marker of inflammtion
What are some common systemic symptoms of RA
SOB
Chest pain
What are the clinical signs of RA
Prolonged morning stiffness - longer than 1hr - which eases with movement
Involvement of small joints of hands and feet.
Symmetric distribution.
Positive compression tests of MCP and MTP joints.
Trigger finger
Systemic symptoms
What are some common joint signs of RA
Swelling - feels spongy
Tenderness
Symmetrical involvement
Not able to make fists (due to tendon involvement)
What is tenosynovitis
Inflammation of a tendon
Common in the extensor tendon
Can become swollen and sore
If not treated the tendons fray and tear
Describe anti-ccp antibodies
Very specific for RA - 98%
Can be present before symptoms appear
Patients will remain positive for the antibody even after treatment
Related to disease activity and more likely to be associated with erosion - worse prognosis
Describe how X-rays are used in RA
Done in all patients
May see soft tissue swelling, periarticular osteopenia (early disease) and/or erosions (late)
Disadvantage is absence of findings in early disease
Describe how US is used in RA
More sensitive than X ray
More likely to spot synovitis in early disease - shows increased blood flow associated with inflammation
Can differentiate between synovial effusions secondary to OA and
synovitis secondary to RA
Detects more MCP erosions
Describe how MRI scans are used in RA
Most sensitive investigation - gold standard
However very expensive so used sparingly
Can monitor disease activity, detect erosions early, asses tendon integrity and distinguish synovitis
What is the DAS28 score
A score that assesses disease activity in RA
Investigates 28 joints in the body
Also includes how patient feels on a scale and an inflammatory marker (CRP or ESR)
What are the thresholds for the DAS28 score
> 5.1 Active disease.
3.2- 5.1 Moderate disease.
2.6-3.2-Low disease activity.
Less than 2.6 Remission.
Give an overview of RA management
Recognise early refer to rheumatology Start on DMARDs - early and aggressive in therapeutic window Treat symptoms with NSAIDs and steroids Multidisciplinary approach
Describe the steps of RA treatment
Step 1 - NSAID for symptoms
Step 2 - add steroid
Step 3 - add first DMARD
Step 4 - add another DMARD etc
How are steroids used in RA
Improve symptoms and reduce radiological damage
Used in combination with DMARDs - bridge as DMARD takes effect
Given orally, IM or IA
Not used long term due to side effects
Name 4 common DMARDs
Methotrexate
Sulfasalazine
Hydroxychloroquine
Leflunomide
What DMARD is first line
Methotrexate
In what order are DMARDs given
1st = Methotrexate 2nd = Sulfasalazine (used second line or alongside MTX) 3rd = Hydroxychloroquine (never used alone as weak)
Patients on DMARDs need regular monitoring - true or false
True
Drugs have many side effects
MTX - LFT and FBC
What are some side effects of Methotrexate
Nausea, vomiting and diarrhoea Rash Mouth ulcers Alopecia Increased infection risk
Liver function derangement - check LFT regularly
Bone marrow suppression Can cause pneumonitis - allergic inflammatory reaction
What are biologic agents
Specialised drugs that inhibit parts of the immune pathway such as cytokines and cells
Can be used in RA
What is the major risk with biologic agents
Increased infection risk as immune system is inhibited
Can reactivate latent TB etc
How are people recommended for biologic treatment
Expensive treatment so must meet certain criteria
Failure to respond to 2 DMARDs and a DAS28 greater than 5.1 on 2 occasions
What are the main complications of untreated RA
Severe joint damage and deformity
e.g. swan necking
What signs of RA may be seen on imaging
Soft tissue swelling Periarticular osteopaenia Bone demineralisation - darker on x-ray Inflammatory pannus - can destroy bone Joint deformity and erosions Ankylosis - joint fusion
What causes the soft tissues to swell in RA
Synovial proliferation and reactive joint effusion
What causes bone demineralisation in RA
Hyperaemia
Results in periarticular osteoporosis (around joint)
Which joints commonly fuse in RA
Sacro-iliac
Spine
Why isn’t it good if you see RA features on X-ray
Mostly show bone and joint damage that’s already happened
Hard to pick up early changes
By this stage its often too late to modify or prevent the disease
What are the seronegative arthritis’
Psoriatic arthritis - affects small joint of hands and feet
Ankylosing spondylitis
Reiter’s syndrome - affects lower limb joints
What early arthritic signs can be seen on US
Thickening of synovium Increased blood flow
What early arthritic signs can be seen on MRI
Bone marrow oedema
Early inflammation and bone erosion
Why do patients with RA get early morning stiffness
Increased viscosity of synovial fluid secondary to
inflammation
Eases with movement
Which age groups can be affected by RA
RA can affect any
age group and even children
RA is more common in men - true or false
False
More common in women - 3:1
Smokers
are more likely to be more resistant to treatment in RA - true or false
True
Also more likely to have anti-CCP antibodies
Rheumatoid factor may be positive in which other conditions
Sjogren`s syndrome, vasculitis, infections and
malignancy
Which joints are typically the first to erode in RA
The 5th MTP joint in the foot and the ulnar styloid in the wrist
Hand and feet X-ray are typically used as the baseline as a result
Which other tablet must be taken alongside methotrexate
Folic acid
MTX prevents it from entering cells
MTX given as a weekly dose followed by folic acid at least 24 hours later on the other 6 days
Methotrexate is contraindicated in which patients
Severe lung disease - due to pneumonitis risk
Women of childbearing age not on contraception - highly teratogenic
Alcoholics - hepatotoxic so they are higher risk
Sulfasalazine is contraindicated in which patients
Those with with allergy to septrin
G6PD deficiency
Best avoided in autoimmune diseases like SLE as can cause drug induced lupus
List side effects of sulfasalazine
Diarrhoea Rash Mouth ulcers Headache It can cause cytopaenias and liver abnormalities
Hydroxychloroquine is used alone in RA
False - used as triple therapy with MTX and sulfa
However
in autoimmune diseases like SLE and Sjogren`s, it has been shown
to reduce fatigue, improve arthralgia and reduce progression of the
disease and is used in isolation.
List side effects of hydroxychloroquine
GI side effects and rash
Very rarely maculopathy - patient must get annual eye tests
Why must people be screened for TB before starting biologics
Risk of reactivation due to drug effect on immune system
Comprimises the granuloma containing the TB as held together by TNF - therefore anti-TNF high risk
What is the major contraindication to starting biologic therapy
Any active infection
How long do DMARDs typically take to work
12 weeks
Steroids are given as a bridge
When are RA patients given long term steroids
If they have severe organ involvement such as lung or kidney involvement
List some side effects of steroids
cataracts, diabetes, weight gain, osteoporosis (consider bone protection) etc
Why must older patients with RA have DEXA screening
Risk of osteoporosis due to osteoclastic activation by
inflammatory cytokines seen in RA
