RF-test... Rhomatoid Factor
storage: for 72 hrs in 2-8 c
reagent:latex caoted with IgG
sensitivity: 8 IU/ml
dilution: 1:.2 , 1:4 , 1:8 ......etc
appearance of coaggulation mean positive
titer is the last positive for example: 1:4 is the last positive so the titer 32
What is being tested?
This test detects and measures rheumatoid factor (RF) in the blood.
RF is an autoantibody, an IgM (immunoglobulin M) protein
that is produced by the body’s immune system.
Autoantibodies usually attack the patient’s own tissues, mistakenly identifying them as “foreign.”
While the role of RF is not well understood,
it is not thought to directly cause joint damage but to promote the body's inflammation reaction,
which in turn contributes to autoimmune tissue destruction.
When is it ordered?
The test for RF may be ordered when a patient has signs of RA. Symptoms may include
and morning stiffness in the joints, nodules under the skin
, and, if the disease has progressed, evidence on X-rays of swollen joint capsules and loss of cartilage and bone.
An RF test may be repeated when the first test is negative and symptoms persist.
The RF test also may be ordered when a patient has symptoms suggesting
Symptoms may include an extremely
and joint and muscle pain.
Symptoms may also be mixed as patients may have more than one autoimmune disorder. Patients with RA and/or Sjogren’s syndrome may also have other connective tissue disorders such as Raynaud’s syndrome, scleroderma, autoimmune thyroid disorders, and systemic lupus erythematosis.
The RF test is sensitive but nonspecific.
It is most closely associated with rheumatoid arthritis (RA) but may also be present in a variety of other autoimmune disorders, such as Sjِgren’s syndrome, in some persistent bacterial and viral infections, and it can be found in a small percentage of healthy people