Rheumatoid Arthritis - Diagnosis
The history given by patients is usually sufficient to arrive to a probable diagnosis of RA. However, certain tests may be required to confirm the diagnosis:
- Complete blood count: This usually reveals mild anaemia along with an increased white blood cell count.
- Erythrocyte sedimentation rate (ESR): This is usually elevated in most cases of RA.
- Rheumatoid Factor: This test is positive in almost 70 to 90% patients with RA symptoms, but may not be necessarily present in all the cases. The titer of Rheumatoid factor is important to judge the clinical course of the disease. Patients with a high titre usually exhibit more severe joint disease and greater functional disability. Those with a low titre have a mild course of the disease. There may also be cases in which the Rheumatoid factor is positive but the patient may not have the signs and symptoms of RA.
- Serum albumin: This may be lower than normal.
- Anti-nuclear antibody: This test is also frequently positive.
- C-reactive protein test: This can be used to monitor the response to therapy.
- X-rays of joints: In the early stages, there may be only soft tissue swelling seen on the X-rays. In the later stages, loss of joint spaces may be seen. Advanced stages of RA are marked by erosions of the bones and deformities.