Rheumatoid Arthritis Flashcards
What is the definition of RA?
Symmetrical inflammatory arthritis affecting mainly the peripheral joints which if untreated can lead to joint damage and irrevesible deformities leading to loss of function and increased morbidity and mortality
What areas of the spine can RA affect?
C1 and C2 as these are the only areas with synovial fluid
What gene mediates RA?
HLA-DR4
What are environmental triggers of RA?
Infections
Stress
Cigarette smoking
What is the main structure involved in RA?
Synovium (lining of inside of syovial joint capsules and tendon sheaths)
What joints are commonly affects by RA?
C1/C2 Hand joints: PIP, MCP, CPC Elbows Shoulders TMJs Knees Hips Ankles Feet
What is a pannus?
Inflammation and proliferation of the synovium leads to formation of pannus and destruction of cartilage, bone, tendons, ligaments, and blood vessels. Basically, the hypertrophied synovium is called pannus.
What is the immunopathogenesis of RA?
Antigen present to T cell and will activate this. This will cause the activation of macrophages to release pro-inflammatory cytokines
It will also cause B cells to be activated leading to the producion of Rheumatoid factor
What pro-inflammatory cytokines will macrophages produce?
TFN-alpha
IL-1
IL-6
What will inflammation in the joint and release of pro-inflammatory cytokines and RF result in?
Osteoclast stimulation
Formation of pannus
Joint destruction
What is early RA?
Less than 2 years than symptoms onset
What effect can drugs in the first 3 months of symptoms have?
Disease modifying window
How is RA diagnosed?
History and clinical examination Routine blood testing - anaemia or raised platelets Inflammatory markers (CRP, ESR/PV) Autoantibodies Imaging
What systemic involvement can be present with RA?
SOB
Coughing
Chest pain
Lung and kidney involvement is common
What classification critera is used for RA?
ACR/Eular
>6 points is definite RA
What are the clinical features of RA?
Prolonged morning stiffness
Involvement of small joints of hands and feet
Symmetric distribution
Positive compression tests of MCP and MTP joints
What are the clinical presentations of RA?
PIP, MCP, wrist and MTP synovitis Monoarthritis Tenosynovitis Trigger finger Carpal tunnel syndrome Polymyalgia rheumatica Palindromic rheumatism Systemic symptoms Poor grip strength
What autoantibodies are associated with RA?
Rheumatoid factor
Anti-CCP antibodies
What imaging modalities are utilised for RA?
Plain x-ray
Ultrasound scanning
MRI
What can plain x-rays show?
Soft tissue sweeling
Osteoclast activation will cause erosion
What can ultrasounds detect?
Detect up to 7x more MCP erosions than plain x-rays in early RA
Will detect increased blood flow to inflammed synovium
What can MRIs detect?
Bone marrow oedema on MRI is associated with inflammatory joint disease and a forerunner of erosion
Integrity of tendons
Can distinguish synovitis from effusions
What is DAS28?
Assessment of disease activity score
What are the different scores in DAS28?
> 5.1 is active disease
3.2-5.1 is moderate disease
2.6-3.2 is low disease activity
Less than 2.6 is remission
What is the use of steroids in RA?
Important in management in RA, serve as a bridge between diagnosis and immunosuppresant therpay as these take about 6-8 weeks to take effect
What can be used for pain in RA?
NSAIDs; diclofenac, ibuprofen, aspirin, naproxone, indomethacin
What is the RA treatment pyramid?
Asprin/ NSAIDs Steroids DMARD #1 DMARS #2 DMARS #3
What are DMARDs used in RA?
Methotrexate
Sulfalazine
Hydroxychloroquine
Steroids - short term
When will biological agents be deployed?
If on 3 DMARDs but DAS28 is still above 5.1
What is the dosage of methotrexate?
15mg with rapid escalation to 25mg a week
Folic acid 24hrs after MTX dose
What blood tests need to be performed whilst on DMARDs?
LFTs
FBC
What lung problem can MTX cause?
Pneumonitis
What is a swan neck deformity?
DIP flexion with PIP hyperextension
What is boutonnieres deformity?
PIP flexion with DIP hyperextension
What pregnancy councelling needs to be given for patients with RA?
Methotrexate is teratogenic, so if wanting to start a family, methotrexate needs to be stopped by males and females 3 months before conception, during pregnancy and during breast feeding
Switch to alternative such as suflalazine which is safe in pregnancy
