Rheumatoid Arthritis Flashcards
what is RA
symmetrical inflammatory arthritis affecting mainly the peripheral joints
if untreated what can RA lead to
joint damage, irreverisble deformities, loss of function, increased morbidity and mortality
who is more likely to get it men or women
women (x3)
what age group can be affected by RA
any
what part of spine can be affected
just C1 and C2
what gene mediates RA
HLA-DR4
what are the potential triggers for RA
smoking, infections, stress
what do the severity and course of RA depend on
genetic factors and presence of auto antibodies
what is the link to smoking
smoking cause proteins in the lungs to become citrullinated (irreversible) and antobodies are created against these which also target the joints
what is the main structure involved in RA and how is it affected
synovium- gets thickened and inflammed
what is the synovium
lines the inside of joint capsules and tendon sheaths
what joints are synovial
C1,C2, hand, wrists, elbows, shoulders, TMJs, knees, ankles, feet, hips
what is a pannus and how is it formed in RA
an abnormal layer of fibrovascular tissue or granulation tissue
Inflammation and exuberant proliferation of the synovium leads to formation of pannus and destruction of cartilage, bone, tendons, ligaments, and blood vessels. Pannus= the hypertrophied (enlarged) synovium
how is the inflammatory cascade perpetuated
inflamed synovium caused increased blood flow- more antibodies and inflammatory cells
how does bone erosion occur in RA
as osteoclasts activated by proinflammatory cytokines
cartilage cells are prevented from being regenerated
describe the immune pathogenesis of RA
antigen (unknown) presented to niave T cells which is activated and stimulates B cells to produce rheumatoid factor and IL-6 and macrophages to produces IL-1 and 6 and TNF alpha
net result is osteoclast stimulation, hypervascular pannus and destruction of cartilage and joint
what is the theraputic window for rheumatoid arthritis
when it is in early stages (first three months)
what defines early RA
less than two years since symptom onset
what is tendonsynovium
the synovium surrounding a tendon, can be affected by RA
the involvement of larger or smaller joints produces a higher ECR/EULAR score
smaller joints
what are the symptoms of RA
will be fit and well then joints will start to be sore
early morning stiffness lasting 30-hour or even until lunchtime
swelling of the joints that is symmetrical and tender
involvement of small joints of hands and feet
positive compression tests of metacarpophalangeal (MCP) and metatarsalangeal (MTP) joints
why do you get early morning stiffness
as synovial fluid gets thicker overnight due to lack of movement
what diagnostic tests can be done
mostly history and clinical exam
blood tests- anaemia of chronic disease, raised platelets
inflammatory markers (CRP, ESR, plasma viscosity)
autoantibodies (seen in 70% of cases)
imaging (x rays of hands, feet and chest as a baseline)
systemic exam- listen for involvement of the lungs, test reflexes and sensations
what does RA in the feet feel like
walking on pebbles