Rheumatoid Factor Test

Rheumatoid factor test is done in suspected cases of rheumatoid arthritis presenting with typical joint pain, early morning stiffness, redness and swelling. It may often be prescribed by the doctors to differentiate from other types of arthritis.

Rheumatoid factor test measures the presence or absence of RA factor in blood.

The blood sample is taken from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a  little sting when the needle goes in or out. This usually takes less than five minutes.

RA factor present or positive (high) usually indicates the diagnosis of rheumatoid arthritis. However, it may also be positive in certain other autoimmune disorders like Systemic lupus erythematosus (SLE), Sjogren's syndrome, mixed connective tissue disorders, inflammatory lung diseases, and certain cancers. The RA factor test may also be positive in certain healthy individuals especially the elderly population. CCP antibody is more specific for diagnosis of rheumatoid arthritis. 
RA factor absent or negative (low) makes diagnosis of rheumatoid disease unlikely. However, in few patients suffering from rheumatoid arthritis both CCP antibody and RA factor can be absent