Rheumatoid Arthritis Flashcards
what is rheumatoid arthritis?
symmetrical inflammatory arthritis affecting mainly the peripheral joints
what can happen if rheumatoid arthritis isn’t treated?
can lead to joint damage and irreversible deformities leading to loss of function and increased morbidity and mortality
what does rheumatoid arthritis affect?
articular and extra-articular structures
who gets rheumatoid arthritis?
can affect men and women but more common in women
any age
1% of population
what causes rheumatoid arthritis (RA)?
can be triggered by infection, stress, smoking
what mediates RA?
HLA-DR4
is RA always the same?
no
severity and course can vary
possible depend on genetic factors and presence of autoantibodies (worse prognosis)
what is the main structure involved in RA?
synovium C1 and C2 hand wrists elbows shoulders TMJ knees hips ankels feet
what is synovium?
lines inside of of synovial joint capsules and tendon sheaths (tenosynovium)
makes direct contact with synovial fluid which acts as a joint lubricant?
what happens to the synovium?
synovium becomes inflamed > spongy mass of inflammation > increased blood flow > more inflammatory cells
inflammatory cascade activates osteoclasts which erode the bone (early osteoarthritis)
what is the end result?
pannus
highly vascular swollen inflamed synovium
describe the psthogenesis of RA?
unknown antigen presented to T cell > T cell activated > stimulates B cells and macrophages > macrophages release cytokines (TNF alpha, IL6 and IL1), B cell produce antibodies (rheumatoid factor) > icreased osteoclast proliferation, inflammation and joint destruction etc
definition of early RA?
< 2 years from symptoms onset
when is the windown of opportunity where disease can be modified?
first 3 months
features of RA?
short history early morning stiffness (>30 mins/1hr) swelling pain in synovial joints >6 weeks duration
how is RA diagnosed?
history/clinical examination (mainly) Blood test inflammatory markers (CRP,ESR) Autoantibodies (rheumatoid factor - only in 70%) Imaging (hand, feet, chest)
what causes early morning stiffness?
thick protein synovial fluid build up during sleep
clinical examination of RA?
swelling in joint symmetrical tenderness in joint loss of function (cant make a fist) positive compression test of MCP and MTP joints
what blood tests are done for RA?
FBC (anaemia, raised platelets)
describe synovium in RA?
hypervascular
inflamed
attracting lots of inflammatory cells
RA X ray?
normal in early stages
changes only seen late on
what is the compression test?
if a gentle squeeze on the joint causes pain
give some possible clinical presentations of RA
PIP, MCP, MTP , wrist synovitis mono/teno synovitis trigger finger (bent and straightens with a click) carpal tunnel polymyalgia rheumatica palindromic rheumatism systemic symptoms poor grip strength
is gout continuous? what are the implications of this?
no
comes and goes so can be confused with palindromic rheumatism
however doesn’t occur in women before menopause
what does extensor tenosynovitis vs synovitis look like?
tenosynovitis = swelling not over the joint, but over the tendons (e.g back of hand) synovitis = over the joints
what can tenosynovitis cause?
fraying and destruction of the tendon
what are the 2 types of auto-antibodies produced in RA?
rheumatoid factor (Rheumatoid IgM) - only 70% specific Anti CCP antibody - 90-99% specific so more used
what are anti CCP antibodies?
against cyclic citrullinated peptide
present for many years before symptoms
associated with smoking history and erosive damage
stays positive even after treatment
how is imaging used in RA?
plain X rays of hands, feet and chest US MRI can show soft tissue swelling, erosions and periarticular osteopaenia? normal in early stages
which imaging is more sensitive for RA?
US and MRI
more sensitive in early stages
can show synovitis and erosions earlier
what is DAS 28?
scoring of joint disease severity lower DAS (<2.6) = less damage to joint
when are biological treatments used for joint disease?
DAS28 > 5.1 after 2 DMARDs
how is RA managed?
early disease modifying anti-rheumatic drugs (DMARDs) for all RA patients
NSAIDs and steroids as adjuncts
patient education
immunosuppresants
definition of remission?
DAS28<2.6
treatment pathway for RA?
aspirin/NSAIDs + steroids + DMARD 1
- add DMARD 2
- add DMARD 3
- gradually withdraw treatment
name some DMARDs
methotrexate sulfasalazine hydroxyxhloroquine combination of first 3 leflunomide gold injection, penicillamine, azathioprine
methotrexate?
first line
escalated from 15-25mg/week
how are DMARDs used?
methotrexate first line
combination of 3 often used
what are biological agents?
inhibit parts of immune pathway anti TNF (infliximab) certolizumab, golimumab T cell receptor blocker (abatacept) B cell depletory (rituximab) IL6 blocker (tocilizumab) JAK 2 inhibitor - tacitinib
complications of untreated RA?
deformation of the joint
how are steroids used?
only to bridge between therapy
for flares only
