Jump to content. A rheumatoid factor RF blood test measures the amount of the RF antibody present in the blood. Normally, antibodies are produced by the immune system to help destroy and eliminate invading bacteria and viruses that can cause disease.
RA is a chronic disease that leads to inflammation of your joints. In some cases, the inflammation may be so severe that it affects how your joints function. It can also cause joint deformities.
What do they measure? What do the numbers mean? This post is all about demystifying RA blood tests.
Rheumatoid arthritis RA is a chronic autoimmune disease that primarily affects the joints, but can affect other parts of the body. Diagnosing and managing RA involves clinical evaluation by a rheumatologist, as well as several different laboratory tests that require blood work. The results of these tests may be used in two ways:.
A rheumatoid factor test measures the amount of rheumatoid factor in your blood. Rheumatoid factors are proteins produced by your immune system that can attack healthy tissue in your body. High levels of rheumatoid factor in the blood are most often associated with autoimmune diseases, such as rheumatoid arthritis and Sjogren's syndrome.
Rheumatoid factor RF is a blood test that measures the amount of the RF antibody in the blood. Most of the time, blood is drawn from a vein located on the inside of the elbow or the back of the hand. You may feel slight pain or a sting when the needle is inserted.
Rheumatoid factors are antibodies directed against the Fc region of immunoglobulin G. First detected in patients with rheumatoid arthritis 70 years ago, they can also be found in patients with other autoimmune and nonautoimmune conditions, as well as in healthy subjects. Rheumatoid factors form part of the workup for the differential diagnosis of arthropathies.
Previously, seropositivity was defined in terms of an antibody called rheumatoid factor RF. Rheumatoid factor is an antibody directed to sites on other antibodies and can be detected by a variety of tests. While most patients with anti-CCP antibodies are also positive for rheumatoid factor, the RF antibody can occur in patients with many other conditions, including infection. For one, people with seropositive, or anti-CCP-positive, disease have a common sequence of amino acids called the shared epitope.
Rheumatoid arthritis RA classically presents as a symmetrical arthritis, although a single large joint synovitis may be the initial presenting symptom. Patients of any age or sex may be affected; however, the disease most often occurs in young, middle-aged women. A patient with swelling of at least 1 large or multiple small joints that cannot be associated with another defined clinical condition should be tested for RA.