PBL 2 Flashcards
what are the signs and symptoms of rheumatoid arthritis?
insidious onset throbbing/aching pain in joints symmetrical early morning stiffness >30 mins normally >5 joints affected warmth, redness, swelling in joints fever malaise muscle weakness low appetite nodules, particularly around pressure points anaemia progressive SOB ulnar deviation boutonniere deformity swab bec deformity baker cyst
what joints are typically affected in rheumatoid arthritis?
smaller joints- metacaprle phalangeal, metatarsophalangial, proximal interphalangeal
wrists
can affect shoulders, elbows, knees and ankles
which arthritis responds bet to NSAIDs
rheumatoid
what is ulnar deviation?
when your metacarpophalangeal joints, become swollen and cause your fingers to bend abnormally toward your little finger
what is boutonniere deformity?
injury to the tendons that straightens the middle joint of your finger so the middle joint of the injured finger will not straighten, while the fingertip bends back.
what is swan neck deformity?
a flexion of the base of the finger, an extension of the middle joint, and a flexion of the outermost joint.
what is a baker cyst?
fluid-filled swelling that develops at the back of the knee
aka popliteal fossa
whats the cause of rheumatoid arthritis?
a combination of genetic predisposition and environmental factors causing modification of our own antigens/type2 collagen/vimentin through citrullination. the body recognises the mutated proteins as foreign = dysregulated inflammation = damage to bones and cartilage
what are 2 examples of genes that predispse us to rheumatoid arthritis?
HLA-DRB1 and HLA-DR4
what are some environmental factors that predispose us to rheumatoid arthritis?
cigarette smoke, infections
what cytokine is released by T helper cells to cause helper cell proliferation?
IL-2
what happens when T helper cells activate B cells in rheumatoid arthritis?
they produce antibodies which attack cyclic citrullinated peptides and those that attack our own IgG antibodies known as rheumatoid factor
what are rheumatoid factors?
IgM antiboides that attack our own, modified IgG antibodies
what are anti-CCP?
a type of autoantiodies that can attack cyclic citrullinated peptides
how do anti-CCP and rheumatoid factor cause joint injury?
antibodies enter the joint space and form immune complexes which activate the complement system and cause joint inflammation and injury
what inflammatory cytokines are released by phagocytes in rheumatoid arthritis?
TNF-alpha, IL-1, IL-6
what cytokine do T helper cells release in rheumatoid arthritis?
IL-17
why do we get pannus formation in rheumatoid arthritis?
white blood cells attack the synovium, releasing proteins that cause angiogenesis. This increased blood flow encourages tissue growth at an accelerated rate.
cytokines also stimulate fibroblast-like synoviocytes which cause synovial membrane proliferation
what is a pannus?
abnormal layer of fibrovascular tissue or granulation tissue over the joint surface
why is the risk of osteoporosis higher in RA patients?
as the inflammation causes increased expression of RANKL which activates more osteoclasts
why do we get cartilage breakdown in rheumatoid arthritis?
fibroblast-like synoviocytes secrete proteases which break down proteins in articular cartilage, leaving exposed unprotected bone which can rub together
why do we experience fever in rheumatoid arthritis?
IL-1 can escape into the bloodtsream and act as a pyrogen in the brain