Rheumatoid arthritis Flashcards
What is inflammation and what does it involve?
a reaction of microcirculation
movement of fluid and WBCs into extravascular tissues
proinflammatory cytokines
How does crystal disease present?
rapid onset of symptoms
very red and hot joints
What features of the clinical history may point the pt history in the direction towards gout?
use of diuretics
obesity
hypertension
alcohol
How does infection of the joints present?
rapid onset of symptoms
very read and hot joints
What are the features of inflammatory joint disease?
pain eases with use
stiffness mostly in early morning and in the evening and in the middle of the night
welling in synovial and can be bony
hot and red
may be a younger pt, may have psoriasis and FH
joint distribution - e.g. RA in the hands and feet
responds to NSAIDs
what are the features of degenerative joint problems?
pain increases with use
may hear clinks and clunks
stiffness that is not prolonged and lasts less than 30 mins
swelling that is bony not synovial
not clinically inflamed i.e. not red or hot
older pts or pts who have done a lot of sport - wear and tear,
weight bearing joints
less response to NSAIDs
in a synovial joint, what are the two articulating bone surfaces covered in?
hyaline/articular cartilage
what is the fibrous capsule of a synovial joint lined by?
synovium
what is the joint space of a synovial joint filled with?
synovial fluid
What type of joint does RA affect?
synovial joints
What are the three main types of joint?
synovial
fibrous
cartilagenous
What are the two subcategories of cartilaginous joints?
synchondrosis
symphysis
What are synchondrosis made from and give an example of this type of joint in the body
hyaline
costal cartilage
what are symphysis joints made from and give examples from the body
fibrocartilage
symphysis pubis
intervertebral discs
what are the changes that happen in RA joints?
destruction of the hyaline cartilage in the synovial joint
the synovial membrane that lines the fibrous capsule is inflamed
the joint capsule itself is inflamed
pannus formation - = hypertrophied synovium. Inflammation and exuberant proliferation of the synovium leads to formation of pannus and destruction of cartilage, bone, tendons, ligaments, and blood vessels. It is a type of granulation tissue that releases IL-1 and this causes cartilage destruction and bone erosion
what are the two pathological characteristics of the synovium in RA?
inflammation and proliferation
what are the features of the inflammation of the synovium in RA?
chronic inflammation
infiltration of lymphocytes, macrophages and plasma cells
what are the characteristics of the proliferation of the synovium in RA?
pannus - grows over the articular cartilage
what are the features of bone loss in RA?
focal EROSION
periarticular osteoporosis
generalised osteoporosis in the skeleton
there is both bone loss and cartilage loss in RA, T or F?
true
how is cartilage lost in RA?
- pro-inflammatory cytokines are released from T cells, macrophages, fibroblasts and macrophages
- these cause the release of matrix metalloproteases from chondrocytes
- the MMPs cause cartilage destruction
give examples of pro-inflammatory cytokines released by macrophages, T cells and fibroblasts in RA that cause MMP release
TNF alpha
IL-1
rheumatoid arthritis is more common in women T or F?
true
How can arthritis be described?
symmetrical, deforming polyarthropathy
which part of the body is most commonly affected by RA?
hands and feet
Is RA autoimmune?
yes
where can extra-articular involvement occur in RA?
lungs heart GIT skin eyes kidneys
What are the symptoms of RA?
joint pain that is worse in the morning joint pain may improve with activity morning stiffness that lasts for several hours (remember degenerative stiffness lasts for a shorter amount of time) loss of function general fatigue and malaise extra-articular involvement
What are the different possible aetiologies of RA?
auto-antibodies present eg Rheumatoid factor and anti-cyclic citrullinated peptide
immune complexes
Immunoglobulins and cytokines present in synovial fluid
defective cell mediated immunity
association with other autoimmune conditions
infection - antigen driven
what features are seen with extra-articular RA in the soft tissues?
nodules
bursitis
tenosynovitis - the inflammation of the fluid-filled sheath (called the synovium) that surrounds a tendon
muscle wasting
describe the histology of rheumatoid nodules
palisading ring macrophages and fibroblasts surrounding and area of central fibrinoid necrosis
surrounding both the above is a cuff of connective tissue containing clusters of lymphocytes and plasma cells
where are rheumatoid nodules found?
on pressure points eg the olecranon but also hands and feet and lungs
what are the extra-articular features of RA in the eyes?
sicca - dry eyes secondary Sjörgen's syndrome episcleritis scleritis (corneal ulceration) necrotising scleritis
what are the neurological extra-articular features of RA?
mild sensory peripheral neuropathy in the legs more than in the arms
entrapment neuropathies
cervical instability
What is an entrapment neuropathy?
soft tissue swelling due to inflammation at site where rigid structures contain nerves
Give examples of entrapment neuropathies and the nerves they affect
carpal tunnel - median nerve
elbow- ulnar nerve
popliteal space and fibular head - common peroneal nerve
tarsal tunnel - posterior tibial nerve
Is atlanto-axial subluxation an erosive process?
yes
What can atlanto-axial subluxation cause?
nerve root compression
spinal cord compression
What are the symptoms of nerve root compression?
severe neck, occipital pain
what are the symptoms of spinal cord compression?
sensory loss
weakness
disturbed bladder function
what are the haematological extra-articular features of RA?
palpable lymph nodes
enlarged spleen
anaemia
What are the causes of anaemia in RA?
anaemia of chronic disease - ie normochromic normocytic
iron deficiency - due to NSAIDs (GI bleeds), prednisolone and peptic ulcers
haemolytic - antibody mediated or drugs
part of pancytopenia - eg due to drugs and Felty’s
What drug in RA can cause pancytopenia?
methotrexate - as it is also a chemo agent
What is Felty’s syndrome?
a triad of seropositive RA, splenomegaly and neutropenia
What are the extra-articular features of RA in the lungs?
pleural effusion diffuse fibrosing alveolitis rheumatoid nodules Caplan's syndrome small airways disease
What are the extra-articular features of RA seen in the heart?
pericardial rub
pericarditis
pericardial effusion
What are the extra-articular features of RA in the kidneys?
amyloidosis
analgesic nephropathy
What causes amyloidosis in RA?
activated macrophages and adipocytes release pro-inflammatory cytokines eg IL -1, IL-6 and TNF alpha
these cause the liver to produce serum amyloid A
What are the extra-articular features of RA in the skin?
vasculitis
small digital infarcts across the nail beds
abrupt onset ischaemic mononeuropathy
What investigations are done for RA and what are the results?
FBC - anaemia High ESR/CRP positive RF - in 80% Anti-cyclic citrullinated peptide Ab (anti CCP) - positive in 80% anti-nuclear antibody - ANA in <50% about 20% are negative for all
What is rheumatoid factor?
an Ab against the Fc portion of IgG ( tail region of an antibody that interacts with cell surface receptors)
What does the Fc portion of an antibody do in its normal job?
modulates immunity
Does positive RF mean RA is the diagnosis and why?
no as just because it is called rheumatoid factor it is not specific to rheumatoid arthritis and can increase in Hep C, SLE, Sjogren’s, systemic sclerosis, primary billiary cholangitis, sarcoidosis
Is anti-CCP specific for RA?
yes
What is citrullination?
conversion of the amino acid arginine into citrulline
this can occur in inflammation
What is the significance of citrullination in RA?
citrullination changes the shape of proteins in the body and the body may recognise these proteins as antigens and display an immune response to them
