An antibody associated with rheumatoid arthritis and other autoimmune disease.
Rheumatoid factor, IgM type, is an antibody that targets part of the body's own immune proteins. It is measured in the blood to help assess inflammatory joint conditions.
Some healthy people have a low level of rheumatoid factor, and it becomes more common with age. So a positive result is not the same as having disease.
Rheumatoid factor is used mainly to help assess rheumatoid arthritis and some related conditions in people with joint symptoms. It is one input, not a diagnosis on its own.
A positive result can occur in healthy people and in other conditions such as chronic infections and other autoimmune diseases. Some people with rheumatoid arthritis test negative. The result must be read by a doctor alongside symptoms and other tests such as anti-CCP antibodies.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
Ranges are guidance only. Rheumatoid factor is an upper-cutoff marker.
| Group | Common upper guide (SI) |
|---|---|
| Adults | up to about 14 IU/mL |
The exact cutoff depends on the assay. Aligned to German laboratory practice (DGKL).
A positive rheumatoid factor occurs in healthy people, more often with age, and in chronic infections, liver disease, and other autoimmune conditions. A negative result does not rule out rheumatoid arthritis. Different assays are not interchangeable.
Often read alongside anti-CCP antibodies, CRP, and ESR when assessing inflammatory joint disease.
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