![]() ![]() Moreover, about 20% of healthy women will have a weakly positive ANA, and the majority of these people will never develop any signs of lupus. It is important to realize that even though 98% of people with lupus will have a positive ANA, ANAs are also present in healthy individuals (5-10%) and people with other connective tissue diseases, such as scleroderma and rheumatoid arthritis. ![]() Another pattern, known as a nucleolar pattern, is common in people with scleroderma. A speckled pattern is also found in lupus. A peripheral pattern indicates that fluorescence occurs at the edges of the nucleus in a shaggy appearance this pattern is almost exclusive to systemic lupus. A homogenous (diffuse) pattern appears as total nuclear fluorescence and is common in people with systemic lupus. The pattern of the ANA test can give information about the type of autoimmune disease present and the appropriate treatment program. Thus, it is not useful to follow the ANA test in someone already diagnosed with lupus. ANA titers may increase and decrease over the course of the disease these fluctuations do not necessarily correlate with disease activity. ![]() A titer above a certain level then qualifies as a positive test result. Each titer involves doubling the amount of test fluid, so that the difference between a titer of 1:640 and 1:320 is one dilution. The titer gives information about how many times the lab technician diluted the blood plasma to get a sample of ANAs. Usually, the results of the ANA test are reported in titers and patterns. The test is read as positive if fluorescent cells are observed. Lastly, the slide is viewed using a fluorescence microscope, and the intensity of staining and pattern of binding are scored at various dilutions. Then, a second antibody tagged with a fluorescent dye is added so that it attaches to the serum antibodies and cells that have bound together. If the patient has antinuclear antibodies, their serum will bind to the cells on the slide. Serum from the blood sample is then added to a microscopic slide prepared with specific cells (usually sections of rodent liver/kidney or human tissue culture cell lines) on the slide surface. In this test, a blood sample is drawn and sent to a laboratory. The test for anti-nuclear antibodies is called the immunofluorescent antinuclear antibody test. 98% of all people with systemic lupus have a positive ANA test, making it the most sensitive diagnostic test for confirming diagnosis of the disease. Anti-Nuclear Antibody (ANA) TestĪnti-nuclear antibodies (ANA) are autoantibodies to the nuclei of your cells. These blood tests are not conclusive by themselves, but combining the tests with certain physical findings can help to corroborate a diagnosis. Several blood tests can be performed to detect specific auto-antibodies and help make the diagnosis of lupus. However, with autoimmune diseases such as lupus, the immune system can produce antibodies (auto-antibodies) that attack your body’s cells as though they were invaders, causing inflammation, damage, and even destruction. Antibodies are your body’s way of remembering an antigen if it enters the body again, the antibodies will recognize it, combine with it, and neutralize it to prevent you from becoming infected. When an invader (antigen) enters the body, white blood cells known as B lymphocytes react by making special types of proteins called antibodies. Blood Tests Used in the Diagnosis of LupusĪntibodies form in the body as a response to infection. ![]()
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