Rumathoid arthiritis Flashcards
What are the key features of RA?
Polyarthirits-more than 1 joint 1 joint in mono arthiritis tend to be symetrical manifest with morning stiff-unlike OA may lead to joint damage and destruction if unckecked
exrta diseases can happen from it-rheumathoid nodules, rare-vasculatits, eposcleritis
test for rheumathoid factor-IgM againt IgG
Who gets RA? Is it genetic?
1% of population-more in women
Important genetic component-not mendelian-usually HLA bases
Smoking contributes to RA risk
What joints are commonly affected by RA?
Metacarpophalengeal joints proxmal interphalangeal Wrists Knees Ankles Metatarsalphalangeal joint
Hands and feet
What classic deforminties do you see?
Boutonniere-deforminity-hyper flexion of POP
Swan neck deformities-hyperflexion at PIP joint and distal IP
Xray-sorta like a dislocation-shift off from ulnar line
affects synovium lining: Extensor tenosynovitis-bumps on back of hand
Olecranon busritis
PIP join synovitis
What are rheumathoid nodules?
Usually happen just distal of elbow-like a bump
Fibrinoid necrosis with histiocytes and connective tissue on top
happen in bad disease (30%)
What is rheumathoid factor?
Its an IgM against an IgG
Form an immune complexes that activate complement and activate inflammation
present in 70% of patient–seropositive
10-15% become seropositive over 10 years
seronegative are better
appart from rheumathoid factor, what is another diagnostic test
Arginine can be made to citruline (not naturally occuring AA)
AB against citruline are common in RA-test for that
maybe because of smoking causing citrullination
What HLA modification causes rhumathoid arthiritis suceptibility?
Individuals that are susceptible tend to carry a conserve AA sequence (epitope)-HLA DRbeta chain-DR1,6,10 can containthat shared epitode
Its role is to present Ag to CD4 T cells
The sequence binds more readily to citruiline
What are the systemic consequences/extra articular features of RA? Why?
malais, weight loss, fever, night sweats (often thought as infection, cancer,)
More uncommon-vasculitis, occular inflammatopm
Neuropathies
Amyloidosis=high serum myeloid that deposits in organs and cause failure
Lung diseases-internal nodules
Felty;s syndrome-triad of spelomegaly, leukopenia and RA
What are the Xray findings that are found in RA?
Early on-nothing-want it to keep it there
Start with osteopenia-bone is lighter on Xray-thinner bone/less dense bone-caused by metalloproteases activity
Later-erosions of margins, blurry of the joins, loss of joint space, irregular
later-deformities and destruction-resorbtion
What can you find inside a synovial joijt?
Synovium around-1/3 cell deep with phagocytes and fibroblast cells producign hyaluronic acid, type 1 collagebn
Fluid-high hyluronic acid-viscous
And cartilage-typeII collagen and proteoglycan
How does the synovium change in RA?
Neovascularisation and lymphangiogenesis
Inflammatory cells use the new places to come to tissue
Deficite of regulation and constant upregulation –TNFalpha drives RA a lot (pro-inflam-cytokine, chemokine release, leukocyte accumulation, angiogenesise, osteoclast activation
=> TNF a is a great therapeutic target
What are the 3 main ideas for curing RA?
Blockign TNFa and
Biological therapy-use AB to block AB, or block IL6 or other factors. IL1 doesnt seem to work in RA
other is cytokine blockade-deplete B cells in RA by administering AB againt B cell surface AG
What is the management of RA?
Physio, OH, hydrotherapy,-remake muscle and keep joint healthy (for more avdances)
DOesnt matter the drug but treat EARLY and AGRESSIVLy
classically; first line;metotrexate and hyxroxycoroquine/sulfosarasine–immune modulators
classes are DMARDs-disease mododifying anti RA drugs
other is steroids-for rapid control, biological therapies
What are DMARDS in RA?
Disease modifying anti RA drugs-
Not currative-usually prevent damage tho
have to take it for a long time and will lead to remission if stopped
4 classic: Methotrexate-first line-but can upset liver Suplhasalazine- Hydroxycoloquine- 1st three are common Leflunomide-rarer Janus kinase inhbit-new
