RA Flashcards
RA is a _________ ________ disease characterized by what type of arthritis and synovitis?
systemic autoimmune disease;
chronic inflammatory arthritis and erosive symmetric synovitis
extraarticular manifestations are __________ and may involve what?
common; may involve almost any organ system
how many joints affected by RA?
common to have polyarticular involvement
affects __% of the population. what is the male to female ratio?
1%; female to male 3:1
what decades of life is RA most common? but can start as early as?
3rd-5th; infancy
__-__% concordance among identical twins
30-50%
RF includes what three antibodies?
IgM, IgG, IgA (IgA is rare tho)
how do RF antibodies cause RA symptoms?
the antibodies form immune complexes due to their ability to bind to the Fc region of IgG; complexes then stimulate complement activation and inflammation (including in the synovial fluid) causing RA symptoms
what three places are RA antibodies found?
blood, synovial fluid and synovial membrane
what is the sensitivity and specificity for RF?
65% sensitive
87% specificity
Can RA occur without positive RF?
yes, in about 30% of cases
probability that a patient has RA _______ in proportion to the titer of RF
increases
what test is more specific for RA than RF?
anti-cyclic citrulline antibodies(anti-CCP)- 90-95%
what are the two Anti-CCP antibodies? how do they relate to RA?
IgM and IgG: they bind to a protein called filaggrin that is produced in inflamed joints, these proteins attract the antibodies (primarily in RA patients)
what is one cytokine that contributes to immune response/inflammation that RA drugs can target?
tumor necrosis factor alpha
what is the hallmark of RA in affected joints?
proliferative synovial pannus
what is a pannus?
destructive inflammatory vascular granulation tissue that extends from synovium to bone not covered by cartilage
pannus progressively destroys what?
bone and cartilage (creates erosions)
what test can distinguish between pannus and cartilage?
MRI
when does pannus show up in someone with RA?
early, even before many symptoms
signs and symptoms of RA? (6)
synovitis, warmth, soft tissue swelling, effusion, tenderness, decreased ROM
what four things might you also see in an RA joint?
subchondral cyst formation (cyst coming off bone in the joint- more common in OA)
juxta-articular osteopenia, joint space narrowing, ankylosis (stiffening or fusion of a joint- occasional)
how do you diagnose RA?
depends on constellation of signs/symptoms that are supported by labs and radiology (no 100% specific lab tests)
what is often the key to RA diagnosis?
involvement of the small joints of hand and feet
ARA diagnostic criteria (7)
must meet 4 of the 7, present for at least 6 weeks
1) . morning stiffness lasting at least 1 hour
2) . at least 3 joint areas simultaneously swelling
3) . swelling in wrist, MCP, or PIP
4) . symmetric involvement of same joint areas
5) . subcutaneous nodules observed by physician
6) . demonstration of positive RF
7) . radiographic changes typical of RA (erosions, bony decalcification)
what’s the usefulness of US in RA disease?
can be used to see pannus and seeing tenosynovitis can be an early predictor of RA development
typical RA distribution?
shoulders, wrists, knuckles and middle joints of fingers, ankles, middle joints of toes, balls of feet
what does a bone scan tell us?
shows us where there is high metabolic activity
what happens at the hand joints when you have RA
fusiform swelling and tenderness at MCP and PIP
- ulnar deviation at these joints too
what is fusiform swelling?
smooth elliptical shape
what two deformities of the fingers can form in RA? describe them both
boutonniere: PIP flexion and DIP extension
swan neck: PIP hyperextension and DIP flexion
what is enthesitis?
inflammation on the joint where tendons/ligaments insert
where can RA nodules occur?
can be outside or inside the body, even in the eye
what can happen to the bones of the wrist?
they can erode, usually ulnar styloid is first to be affected
-radial deviation of wrist
what happens to extensor tendons at the wrist?
synovial proliferation with rupture of extensor tendons (hard to extend fingers actively)
what can happen in the hip with RA?
hip is affected later than most joints but can be axial migration of femoral head with acetabular protrusion
what can you see on the ankles and feet for RA?
Hallux valgus (toe points laterally like a bunion **angulation due to loss of joint integrity collapse of arches, MTP joint synovitis, pain in balls of feet,
what are some extra articular manifestations? (6)
fever, anorexia, weight loss, fatigue, muscular weakness, increased CVD risk
what skin disease also increases your risk for CVD?
psoriasis
what did a study find out about ACS (acute coronary syndrome) risk factors?
clinical markers of inflammatory activity, disease activity and net days of sick leave/disability pension during the first year after RA onset are ACS risk factors
what are rheumatoid nodules?
granulomatous lesions (rubbery) that develop around small blood vessels **most common extra articular manifestation of RA
where do nodules usually occur?
subcutaneous areas exposed to pressure (elbows, knuckles of hand)
treatment of nodules?
no specific therapy to treat but usually surgery
when is there usually organ involvement in RA? (3)
when there’s severe RA, high titers of RF and Anti-CCP, and nodule formation
what two things can RA do to lungs?
pleurisy with effusions and nodules in the parenchyma
what three things can RA do to heart?
nodule formation, myocarditis, valvular fibrosis
** rarely symptomatic
what two things can RA do to the blood/blood vessels?
anemia and vasculitis
what is the hallmark of early RA?
vasculitis
what are some GI complications due to RA?
pretty rare for RA to affect GI except when using NSAIDS
what is best seen on XRAY?
bony erosions: cyst-like radiolucencies best seen at joint margins
(not helpful in early RA though*)
what can be seen on MRI for RA?
distinguishes synovial pannus from cartilage and picks up many other detailed features of joints
what two things can US help with for RA?
can pick up early soft tissue changes and predict disease severity
what anemia is RA associated with?
normocytic
what four lab tests are normally elevated in RA?
ESR, CRP, WBC (leukocytosis), and ANA (antinuclear antibody- not always high)
can RF results change over time?
yes, usually absent in 1st year but eventually positive in 80%
what two things are important about anti-ccp?
1) may be elevated before symptoms in patient who will develop RA later on
2) . CCP-positivity predicts worse disease
what antibodies are found on labs for RA?
anti ss-DNA antibodies
what does synovial fluid analysis show?
WBC range from 2,000-50,000 (mostly neutrophils- 50 to 80%), glucose is usually normal (unless chronic and severely inflamed)
what does a WBC count over 50,000 in synovial fluid suggest?
infection- think more septic arthritis
what are the four progressions of RA?
1) . spontaneous remission (10-20% of patients)
2) . remitting: recurrent flares but patient returns to normal during flares
3) . remitting progressive: no complete return to normal between flares
4) . progression- on-going synovitis and progressive pain, swelling and joint damage (MOST COMMON)
what are three non pharmacologic therapies of RA?
1). joint progression
2). exercise
3). nutrition- vitamin D helps prevent and may improve symptoms
(also notes that no climate or diet alters the course of RA)*
what type of drugs are usually used as first treatment?
NSAIDS (symptomatic relief)
what drugs are used for RA flares? what’s another use for them?
steroids for flares AND bridge to DMARDs
what are mainstream RA drugs? how do we use these?
DMARDs
1 or more should be used early in dz course: methotrexate FIRST, most patients require 2nd add on (TNF a inhibitor)
** maybe plaquenil or sulfasalazine as non biologic add on
how does methotrexate treat RA? what do we supplement this with?
inhibits cell division; folate
3 main TNF a inhibitors we use for RA
Adalimumab (Humira), Infliximab, Etanercept
methotrexate combined with what TNF inhibitor resulted in 49% remission of early and aggressive RA after 2 yrs of treatment?
adalimumab
how does leflunomide help RA?
decrease production of pyrimidines, inhibiting T and B cell function
how does rituximab help RA?
depletes B cells
who do you not want to start on methotrexate?
someone who has cancer or an active infection
what are some surgical benefits for RA?
control pain, repair ligaments/tendons, remove inflamed synovial tissue, restore function
