Diagnosing Rheumatoid Arthritis
This chronic inflammatory disease has been known to be very hard to diagnose in its earlier stages. The early signs and symptoms of rheumatoid arthritis have the tendency to mimic those of a number of other diseases. During the standard physical, a doctor can check the joints for any tenderness, swelling, or redness. Most physicians will also be sure to test the reflexes and the muscle strength. When it comes to diagnosing rheumatoid arthritis, there is no one test or physical manifestation which can confirm that it is indeed RA.
Image Testing for RA
Imaging Tests used to help diagnose rheumatoid arthritis:
• Magnetic Resonance Imaging (MRI)
• Color Doppler and power Doppler ultrasounds
Many people will have an x-ray of their hands and feet to check for rheumatoid arthritis or polyarthritis. Unfortunately, there may be no distinguishing changes during the earlier stages of rheumatoid arthritis. An x-ray may be able to spot some soft tissue swelling or a loss of joint space, which will help doctors to make an early diagnosis of the condition. X-rays that are taken of rheumatoid arthritis in a more advanced stage may find some bony erosion or even some partial dislocation of the joint. A patient should have an x-ray taken of any joint that has been experiencing any pain or swelling.
MRI (magnetic resonance imaging) and ultrasounds have also been used to help successfully diagnose a case of rheumatoid arthritis. In fact, with some of the recent technological advances in ultrasonography, modern pictures can depict 20% more of the joint erosion than the standard radiography. This development was the result of high- frequency transducers, which have improved the spatial resolution of ultrasound images. Doppler ultrasound has also been used to help diagnose synovial inflammation. Active synovitis causes various vascular signals depending on the level of inflammation, and the Doppler ultrasounds can show it. Doctors have been using these images to diagnose earlier stages of rheumatoid arthritis, where it is primarily the synovial membrane of the joint which is affected.
Blood Tests for RA
Many patients will undergo certain blood tests to see if they have rheumatoid arthritis. In fact, most doctors will state that if it seems like a patient may have rheumatoid arthritis, then immunological tests are needed. Even though it is a non-specific antibody, patients will generally be tested for the presence of the rheumatoid factor. Unfortunately, doctors still cannot rule out the possibility of RA, even if a patient does not have the rheumatoid factor. In about 15% of cases, the people with RA do not have the rheumatoid factor. When this is the case, the rheumatoid arthritis is what is known as seronegative. Actually, the rheumatoid factor has a higher chance of being negative during the first year with some patients becoming positive over time. Testing positive for the rheumatoid factor is by no means a conclusive result meaning that a patient has RA. The rheumatoid factor is present in a number of other illnesses, and about 10% of the healthy population would test positive for RF.
New blood tests have been developed which in conjunction with the RF test can help doctors make an accurate diagnosis. Doctors will now test for the presence of anti-citrulinated protein antibodies or ACPAs. Similar to the rheumatoid factor tests, these ACPAs tests come back positive for about 67% of all cases. The major difference is that if there is no rheumatoid arthritis, then the test rarely comes back positive (95% specificity). There are two tests that doctors usually run to determine the presence of ACPAs in patients, the anti-CCP test and the anti-MCV assay.
Rheumatoid Arthritis Early Diagnosis Criteria
In 1987, the American College of Rheumatology (ACR) developed a list of criteria that could be used in the early detection and diagnosis of rheumatoid arthritis. Then in 2010, a revised version of these criteria was developed due to concerns that the 1987 version lacked sensitivity. Many patients did not meet the 1987 criteria until their condition had progressed to a more advanced stage.
The criteria set up in the 2010 revised version by the ACR and EULAR:
• Point value system from 1 to 10
• Any patient with a value of 6 and up could be diagnosed with RA
• Synovitis in at least one joint required for early RA diagnosis
The new criteria established in the 2010 ACR/ EULAR Rheumatoid Arthritis Classification effectively accommodate for the growing understanding of RA, as well as the new improvements that have been made in diagnosing this condition. With the availability of autoimmune diagnostics and the new tests for ACPA, rheumatoid arthritis is being effectively diagnosed at an earlier stage before there is major destruction to the joints. Not surprisingly, these have been given major weight in the revised criteria for early diagnosis. Many of the old RA tests have been edged out by these new tests, which have now shown them to be irrelevant.