The presence of C-reactive proteins in the bloodstream may be an indicator of rheumatoid arthritis, states Healthline. The existence of these proteins is not definitive proof of the disease, so complementary information and tests, such as checking the blood for certain antibodies, are required when diagnosing rheumatoid arthritis.
Normal C-reactive protein levels in the bloodstream are typically less than 10 milligrams per deciliter, Healthline explains. Produced by the liver, the amount of these proteins in the blood of a healthy individual is usually so minimal that it is undetectable using standard tests. Abnormally high levels are typically the result of infections and chronic inflammatory diseases such as lupus, rheumatoid arthritis and Crohn's disease.
The presence of these proteins in the bloodstream is not definitive evidence of rheumatoid arthritis, according to Healthline. Additional information, such as swelling and pain in the joints, duration of certain symptoms and positive tests showing the presence in the bloodstream of an antibody known as the rheumatoid factor, is required in order to definitively identify the disease.
Once treatment has started, physicians may intermittently order additional C-reactive protein tests to track how well a patient is responding to medical care, Healthline states. Ideally, the levels of these proteins in the bloodstream should decline during the course of treatment, but if they rise, doctors may resort to using alternative medications.