Rheumatoid arthritis is an inflammatory autoimmune disease that affects the entire body, and is not limited to the joints. The immune system is triggered off inappropriately, and the body starts to reject its own tissue. The main effect is inflammation (swelling and redness) of the smooth moist synovial membrane that lines the inside of joints. Those most affected are the hands and feet.
It tends to run in families from one generation to the next, and the onset may be triggered by a viral infection or stress. It occurs in one in every 100 people, females are three times more frequently affected than males, and usually starts between 20 and 40 years of age. A juvenile form is known as Still’s disease.
Rheumatoid Arthritis symptoms are very mild, with early morning stiffness in the small joints of the hands and feet, loss of weight, a feeling of tiredness and being unwell, pins and needles sensations, sometimes a slight intermittent fever, and gradual deterioration over many years. Occasionally the disease has a sudden onset with severe symptoms flaring in a few days, often after emotional stress or a serious illness. As the disease worsens, it causes increasing pain and stiffness in the small joints, progressing steadily to larger joints, the back being only rarely affected. The pain becomes more severe and constant, and the joints become swollen, tender and deformed. Additional effects can include wasting of muscle, lumps under the skin, inflamed blood vessels, heart and lung inflammation, an enlarged spleen (Felty syndrome) and lymph nodes, dry eyes and mouth, and changes to cells in the blood.
It is diagnosed by specific blood tests, X-rays, examination of joint fluid and the clinical findings.
The level of indicators in the blood stream can give doctors a gauge to measure the severity of the disease and the response to treatment.
Blood tests that may be used in the investigation of rheumatoid arthritis include rheumatoid factor, cyclic citrullinated peptide antibody test, anti-deoxyribonucleic acid titre, antinuclear antibodies, Beta-2 microglobulin, complement, C-reactive protein, DNA autoantibodies, erythrocyte sedimentation rate, extractable nuclear antigen autoantibodies, HLA-DR4 and latex agglutination.