The presence of either rheumatoid factors or elevated anti-CCP factors in the blood are strong indications that the patient has rheumatoid arthritis, or RA, says WebMD. Rheumatoid factors are antibodies that are present in 70 to 90 percent of patients with RA, and if no rheumatoid factor is present, it indicates the course of the disease may be less severe. An elevated level of anti-CCP antibodies can indicate a patient is more likely to develop severe RA.
Two tests that determine the level of inflammation in the body are the erythrocyte sedimentation rate, or ESR, and the C-reactive protein level, or CRP, explains WebMD. The ESR is normally low in healthy people, but rises with inflammation and often correlates with disease activity. A high CRP indicates significant inflammation or injury in the body. The CRP provides a stronger indication of the degree of inflammation in the body than the ESR, but both tests are useful for monitoring disease activity and response to treatment.
Other tests that help diagnose autoimmune diseases or inflammatory disorders are the HLA-B27, the ANA profile, muscle enzymes, ANCA or complement levels, reports WebMD. These tests can help rule out or confirm particular autoimmune diseases, diagnose associated disorders, or track the course of a disease or treatment.