A positive result on an ANA, or antinuclear antibodies, test should be interpreted light of the patient's medical history, states the American College of Rheumatology. In addition, more testing information must be added to the interpretation to determine if antibodies are being produced to attack foreign bodies.
Positive results have several possible meanings. Three to 15 percent of healthy people have antinuclear antibodies, which typically attack proteins inside the nucleus of foreign cells, reports ACR. Positive ANA results are sometimes caused by pharmaceuticals, so prescriptions, over-the-counter medications and illegal drugs must be considered. In certain cases, cancer leads to high readings.
If the immune system is mistaken and a person's own cells are targeted by antinuclear antibodies, the outcome is often an autoimmune disease, according to ACR. Further investigation after positive ANA results sometimes determines that the antinuclear antibodies have been created to fight an autoimmune disease, such as lupus, scleroderma, mixed connective tissue disease, autoimmune hepatitis or juvenile arthritis.
One common ANA analysis involves a microscopic examination of the blood to search for antibodies that show up in a fluorescent dye, ACR explains. The unit "titer," which describes a substance's concentration within a solution, is used to report results. In addition, the pattern of antibodies, such as homogeneous, diffuse or speckled, is described.