Rheumatoid Factor IgM Unit Converter

Rheumatoid Factor IgM (RF IgM) is an autoantibody, meaning it's an immune protein that mistakenly targets the body's own tissues. Specifically, it's an IgM-class antibody directed against the Fc portion of your own IgG antibodies.

When RF binds to IgG, it forms immune complexes that can deposit in joints and other tissues, triggering inflammation. About 70-90% of people with established rheumatoid arthritis test positive for RF IgM.

However, RF is not exclusive to rheumatoid arthritis. It can also appear in other autoimmune conditions, chronic infections, and even in a small percentage of healthy people.

RF IgM is produced by B lymphocytes, primarily within the synovial tissue of inflamed joints, where B cells form ectopic germinal center-like structures. It is also produced in smaller amounts by B cells in bone marrow, peripheral blood, and lymph nodes.