science of RA Flashcards
what is rheumatoid arthritis ?
chronic symmetric, polyarticular inflammatory joint disease, which primarily affects the small joints of the hands and feet
what is rheumatoid synovitis characterised by ?
inflammatory cell infiltration
synoviocyte proliferation
neoangiogenesis
what to antibodies in RA recognise ?
joint antigens
type 2 collagen
systemic antigens - glucose phosphate isomerase
what is the diagnostic antibody in RA ?
Anti-CCP assays - recognise citrullinated self-proteins
what proteins does anti-CCP recognise ?
a-enolase keratin fibrinogen fibronectin collagen vimetin
what other antibodies are seen in seropositive RA ?
rheumatoid factor - self IgG Fc
anti-citrullinated protein antibody ACPA
what genes are associated with RA ?
HLA-DRB1 locus
PTPN22
CTLA4
c-REL
what are environmental factors contributing to development of RA ?
smoking and bronchial stress (silica exposure)
infection - EBV,CMV, Ecoli, mycoplasma, peridontal
what is the pathogenesis of synovitis in RA ?
villous hyperplasia infiltration of lymphocytes, macrophages, plasma cells intimal cell proliferation production of cytokines and proteases increased vascularity self-amplifying
how is bone destroyed in RA ?
proteases are produced by FLS which can attach and invade cartilage
osteoclasts destroy bones, activated under the influence of RANKL produced by RA synovium
what systemic conditions can RA lead to ?
vasculitis nodules scleritis amyloidosis secondary Sjorgren's syndrome - dry eyes + mouth
what CV disease can RA cause ?
altered lipid metabolism
elevated acute-phase reactants
increased endothelial activation
what mental effects can RA cause ?
fatigue
reduced cognitive function
reduced HPA axis
secondary fibromyalgia
what liver diseases can RA cause ?
elevated acute-phase response
anaemia of chronic disease - increased hepcidin production
what lung diseases can RA cause ?
interstitial lung disease
fibrosis
