Antinuclear antibody test: A test for unusual antibodies that are directed against structures within the nucleus of the cell. Antinuclear antibodies (ANAs) indicate the possible presence of autoimmunity.
The fluorescent antinuclear antibody test (FANA) was designed by George Friou, M.D. in 1957. It is done on a blood sample. The antibodies in serum are exposed to cells and then one determines whether antibodies are present that react with parts of the nucleus of the cell. It is a sensitive screening test used to detect autoimmune diseases.
ANAs are found in patients with a number of autoimmune diseases, such as systemic lupus erythematosus, Sjogren syndrome, rheumatoid arthritis, polymyositis, scleroderma, Hashimoto thyroiditis, juvenile diabetes mellitus, Addison disease, vitiligo, pernicious anemia, glomerulonephritis, and pulmonary fibrosis. ANAs can also be found in patients with chronic infections and cancer. Many medications including procainamide (PROCAN SR), hydralazine, and dilantin can stimulate the production of ANAs.
ANAs are present in approximately 5% of the normal population, usually in low titers (low levels). These persons have no disease. ANA titers lower than 1:80 are unlikely to be significant. Even higher titers are insignificant over the age of 60. Ultimately, the ANA result must be interpreted in the specific context of the symptoms and other test results for the patient. It may or may not be significant in an individual.
Antioxidant: A substance that reduces damage due to oxygen, such as that caused by free radicals. Well-known antioxidants include enzymes and other substances, such as vitamin C, vitamin E, and beta carotene, which are capable of counteracting the damaging effects of oxidation. Antioxidants are also commonly added to food products such as vegetable oils and […]
Antiparallel: A term applied to two molecules that are side by side but run in opposite directions. The two strands of DNA are antiparallel. The head of one strand is always laid against the tail of the other strand of DNA.
Antiparasitic: Effective in the treatment of parasites. For example, nitazoxanide (Alinis) is an antiparasitic medication used to treat diarrhea due to the intestinal parasite Giardia lamblia.
- Antiphospholipid antibody syndrome
An immune disorder characterized by the presence of abnormal antibodies in the blood associated with abnormal blood clotting, migraine headaches, recurrent pregnancy losses (repeat spontaneous abortions), and low blood platelet counts (thrombocytopenia). The abnormal antibodies are directed against phospholipids. (Phospholipids are fats that contains phosphorous). APLS can occur by itself (primary) or be caused by […]
Antiprotozoal: Something that destroys protozoa or inhibits their growth and ability to reproduce. A few of the protozoa of medical importance include Plasmodium (the cause of malaria); Entamoeba histolytica (the cause of amebiasis, amebic dysentery) and Trichomonas vaginalis (a cause of vaginal infection); and Pneumocystis carinii (a common cause of pneumonia in immunodeficient persons). Some […]