Erythrocyte sedimentation rate (ESR), also called “sed rate,” determines if you have inflammation. The sed rate can measure the amount of inflammation present. The test measures how fast red blood cells cling together, fall, and settle toward the bottom of a glass tube in an hour’s time, like sediment. The higher the sed rate, the greater the amount of inflammation. As inflammation responds to medication, the sed rate usually goes down.
Female: 0-20 mm/hr
The immune system is the body’s natural defense against foreign invaders, such as bacteria or viruses. Occasionally, the immune system breaks down and loses the ability to distinguish between its own body cells and foreign invaders. When an invader such as a virus enters the body, the virus creates what is called an antigen. The body’s immune system fights the antigen by creating an antibody. When the immune system fights against its own body cells, it creates autoantibodies that attack the body itself. Antinuclear antibodies are autoantibodies that react against the nuclei (core) of the body’s own cells when these cell parts are mistaken for foreign invaders.
Rheumatoid factor (RF, Latex) measures whether a certain amount of abnormal antibody called rheumatoid factor is in the blood. The majority of people with rheumatoid arthritis (a common disease of inflamed joints that can cause joint alignment problems and loss of function) have a large amount of rheumatoid factor in their blood. However, up to 20 percent of adults with rheumatoid arthritis may never have any rheumatoid factor in their blood. In contrast, about 85 percent of children with juvenile rheumatoid arthritis (ERA) are negative for rheumatoid factor. ERA is a group of diseases, similar to rheumatoid arthritis, that begin in childhood.) It is important to note that having a positive rheumatoid factor will assist in the diagnosis, but the test alone is not conclusive.
Normal Results: <1:10
The antinuclear antibody test (ANA) detects a group of autoantibodies that are found in most people with lupus and scleroderma and in a few people with rheumatoid arthritis. These autoantibodies react with antigens in the nuclei of cells. The antibodies suggest that an autoimmune illness may be present, although many people test positive and have little evidence of serious disease. Specific antinuclear antibody tests are helpful in the diagnosis of certain rheumatic diseases that involve abnormalities in the immune system.
Normal: <1:40, No Pattern
The names of the following tests are abbreviations of more complicated-sounding tests. The diseases for which they are used include:
- systemic lupus erythematosus (multiple-system illness, may involve the skin, joints, kidney, etc.); anti-dsDNA, anti-Sm, anti-Ro/SS-A, and antihistone tests help confirm the diagnosis.
- scleroderma (a marked thickening of the skin); the anti-Scl-70 test helps confirm the diagnosis.
- polymyositis (inflammation of muscles, resulting in muscle weakness, sometimes with joint inflammation); anti-Jo-l and anti-PM-l tests may help confirm the diagnosis.
- Sjogren’s syndrome (disorder marked by dry eyes and dry mouth); anti-Ro/SS-A and anti-La/SS-B tests may help confirm the diagnosis.
- mixed connective tissue disease (a syndrome with a variety of symptoms, including joint inflammation and swollen fingers); the anti-Ul RNP test helps confirm the diagnosis.
Complement tests measure the amount of complement proteins circulating in the blood. Complement tests involve the reaction of antibodies with antigens. These tests usually are reserved for diagnosing or monitoring people with active lupus. Those people with lupus frequently have lower-than-normal amounts of complement, especially if the kidneys are affected.