Rheumatoid Factor Unit Converter

Rheumatoid factor (RF) is an autoantibody produced by the immune system. Unlike normal antibodies that target harmful invaders like bacteria and viruses, RF mistakenly targets the body's own immunoglobulin G (IgG) antibodies.

RF is predominantly composed of IgM antibodies, though it can also exist as IgA or IgG isotypes. When RF binds to IgG, it forms immune complexes that can trigger inflammation, particularly in the joints.

Many healthy people have small amounts of RF in their blood without any health problems. However, elevated levels are often associated with autoimmune conditions, especially rheumatoid arthritis, where RF is found in approximately 75-80% of patients.

Rheumatoid factor is produced by B cells, a type of white blood cell responsible for making antibodies. In healthy individuals, low-affinity RF may be transiently produced in response to infections or other immune stimuli. In autoimmune conditions like rheumatoid arthritis, B cells undergo changes that lead to the production of high-affinity, persistent RF antibodies.