rheumatoid arthritis Flashcards
what is it
autoimmune condition that causes chronic inflammation of the synovial lining of the joints, tendon sheaths and bursa
it is symmetrical and affects multiple joints
‘symmetrical poly arthritis’
who does it affect
3x more likely in women
develops in middle age but can present at any age
family history is relevant and increases the risk
infections and smoking triggers RA
what are the genetic associations for RA
HLA DR4 - rheumatoid factor positive patients
HLA DR1
what is rheumatoid factor and what does it target
it is an autoantibody present in most cases of RA patients
it targets the Fc portion of IgG antibody
what is the function of Fc portion on antibodies
it is used to bind to cells of the immune system - rheumatoid factor targets this portion causing activation of the immunes system against the patients own IgG causing systemic inflammation
what can anti CCP antibodies indicate
they can predate the development of rheumatoid arthritis
these are distributed through circulation and form immune complexes with CCP produced in the inflamed synovium
how does it present
symmetrical distal polyarthropathy
pain
swelling
stiffness
fatigue
weight loss
flu like illness
muscle aches and weakness
*inflammatory arthritis is worse after rest but improves with activity
joints commonly affected
proximal interphalangeal joints > distal ones are almost never affected
metacarps
wrist and ankle
metatarso
cervical spine
large joints ie knee hips and shoulders
what does RA look like in the hands
Z shaped deformity
Swan neck deformity
Boutonnieres deformity
ulnar deviation of the fingers at the knuckles
extra articular manifestations
pulmonary fibrosis
bronchiolitis obliterates
Felty’s
secondary Sjogrens syndrome
Investigations
-check rheumatoid factor
>if RF negative, check the anti-CCP antibodies
-CRP
-ESR
-x-ray of the hands and feet
-ultrasound scan of the joints can be useful to evaluate and confirm synovitis
what are some of the x-ray changes
joint destruction and deformity
soft tissue swelling
periarticular osteopenia
boney erosions
when to refer
NICE = any adult with persistent synovitis
even if they have negative rheumatoid factor, anti-CCP antibodies and inflammatory markers
diagnosis
diagnostic criteria = ACR or ELAR
score based of off:
1.the joints that are involved (more and smaller joints score higher)
2.serology (RF and anti-CCP)
3. inflammatory markers (ESR and CRP)
4. duration of symptoms (more or less than 6 weeks)
Disease Activity Score / DAS28 score
based on the assessment 28 joints and points are given for:
Swollen joints
tender joints
ESR/CRP result
