IMMUNO- Lab 8 RA and RF

what is rheumatoid arthritis

autoimmune disease in which the immune system attacks the synovium that lines the joints

women are more likely to have RA than men

true

what is affected when you have RA

synovial joints; small joints of hand, feet and wrists

age of onset

20 and 40; increases with age up to 65

what is morning stiffness

slowness or difficulty moving the joints that lasts more than 30 minutes later to an hour

symptoms are symmetrical but don’t have to be

true

RA can lead to loss of joint function and deformity

true

what is Rhematoid factor?

an antibody found in patients with RA

whats the % of RF in patients with RA

80%

RF if associated with RA and is CAUSATIVE

false

what antibody is RF

anti-IgG

what does anti-igG bind to

Fc portion of igG to form immune complexes

what are the different classes of RF

igM, igG, IgA

whats RF class can be serologically detectable using latex?

igM

what is used for IgG and IgA classes?

nephelometry

whats value of titer suggests RA

≥ 80

what do the immune complexes activate?

classical complement pathway and increase the inflammatory response

whats another antibody that associated with RA

Anti-CCP (cyclic citrullinated peptide); higher specificity fo RA than RF

whats the soluable component

rheumatoid factor

whats the insoluble component

igG

whats the known?

igG (antigen)

whats the unknown

RF (antibody)

whats the first test for RF

rose-waaler test (hemagglutination test)

true positives

patient have RA

false positives

• leprosy

• syphilis

• SLE

• hepatitis

• TB

• Infectious mononucleosis

true negatives

patients do not have RA

false negatives

• igG or IgA form of RF present

• high titer of RF may cause prozone

• 20% of patients w RA don’t demonstrate RF

specifity of RF kits

>95%