Rheumatoid arthritis Flashcards
female to male ratio
3:1
what is ra and stages
immune system attack the joint
proliferative synovitis leading to cartilage loss and bone erosions
- synovitis: inflamed and thickened- bony erosions start
- pannus
- pannus: granulation tissue and vascularisation
- produces fluid - fibrous ankylosis: fuse connective tissue due to pannus there= reduced mobility
- bony ankylosis
- bone erosions: osteoclasts & granulation tissue =gradual complete loss mobility
factors associated to a poorer prognosis for RA 6
female disability at presentation involvement of MTP joints x-ray damage at presentation smoking positive RF or ACPA
key pathophysiological features of RA
synovitis
cartilage loss
bone erosions
auto-immune
what is the major haplotype assoc. to RA
HLA-dr4
what causes RA
genetic predisposition+environment stimuli eg smoking (damages epithelial so make ab), trauma, stress infection, menopause, post-partum
pathophysiology of RA
- dendritic cells stimulate T cells (th17)
- t cell stimulate B cells to produce AB (rf and acpa)
- synovial macrophages activated by immune complexes
- synovial fibroblasts promotes swelling and damage
- osteoclast activation by RANKL and chondrocytes by cytokines drive cartialge/ bone degrade
- neoangiogenesis- inflamed synovium becomes vascularised
- increases cytokines
which cytokine causes the acute phase response and systemic effects in RA
il6 goes to liver causing the anaemia, fatigue and reduced cognitive function
what is the abnormal tissue that forms in RA replacing articular cartilage called
pannus
what causes the formation of pannus
formed by hypoxic tissue undergoing neoangiogenesis
-causes excess fluid production as releases MMP that degrade catilage and cause bone destruction
what makes up a RA nodule
central area= fibrinoid material
surrounded by proliferating mononuclear cells
function of TNF in RA
stimulate IL1 il8 and il10 activate macrophages increases IL6, PROSTAG Activate osteoclast via il1 promote MMP production
most common affected joints of RA
mcpj pipj wrist elbow shoulder knee back
presentation of RA
polyarthritis symmetrical morning stiffness swelling post-inactivity gelling systemic symptoms: fatigue chronic >6 weeks lung fibrosis
importance of detecting lung fibrosis in ra
can’t use methotrexate
criteria for diagnosis of RA 2010
score >6 -num joints affected and size 1 large=0 2-10 large=1 1-3 small=2 4-10 small=5 -serology rf/acpa=0 low=2 high=3 -duration symptoms <6=0 >6=1 -acute phase reactants esr and crp 0 or 1
