ANA blood test
ANA blood test
Antinuclear antibodies (ANA) refer to the unusual antibodies that are detectable in the blood. ANA are gamma-globulins type of antibodies that are found in patients with certain autoimmune diseases. ANA are directed against certain components found in the nucleus of a cell in the body. These antibodies have the capacity of binding certain structures within the nucleus of the cells. The ANA test was first designed by Dr.George Friou in 1957. The laboratory blood test exposes the antibodies in the serum of the blood to cells. It is then determined whether or not antibodies are present that react to various parts of the nucleus of cells. Hence the term 'anti-nuclear' antibody is used.
Fluorescence techniques are adopted to detect the ANA antibodies in the cells. Thus ANA testing is sometimes referred to as fluorescent antinuclear antibody test (FANA). Nowadays, a method to detect antinuclear antibodies called enzyme linked immunosorbent assay (ELISA) is replacing the previous method of immunofluorescent assay technique. The ELISA method is less likely to produce false positive ANA result than the previous method.
Patterns also give doctors a clue as to the type of illness to look for while evaluating a patient. For instance, the disease Scleroderma shows in nucleolar pattern. If a person does not have any autoimmune disease, it is defined in speckled pattern. An ANA blood test is used in patients who might be suffering from Sjogren's syndrome, rheumatoid arthritis, polymyositis, scleroderma, Hashimoto's thyroiditis, juvenile diabetes mellitus, Addison's disease, vitiligo, pernicious anemia, glomerulonephritis and pulmonary fibrosis. ANA can also be found in patients with conditions that are not considered autoimmune diseases such as chronic infections and cancer.
The result of the ANA test is expressed in titers. A titer of 1 to 80 (1:80) means that antibodies could be last detected when 1 part of the blood sample was diluted by 80 parts of another liquid. Usually this other liquid is a diluted salt solution. A larger second number indicates that the antibodies are present in greater concentration. Therefore a titer of 1 to 320 indicated higher concentration of antibodies in the blood than a titer of 1 to 80. The normal values of ANA blood test is : Titer below 1: 20 or 1:40 depending on the test method used.
Positive ANA test result is suggestive of autoimmune disease. It can also mean that the patient has drug induced lupus. Some drugs and infections can also induce false positive ANA test results. Steroids can cause a false-negative result. Medications, especially antibiotics such as isoniazid, penicillin, and tetracycline, birth control pills, lithium and some diuretics such as chlorthalidone can interfere with the test and affect the accuracy of the ANA test result.
Raynaud's disease is a condition where the extremities of the body, primarily the fingers and toes experience a reaction to cold. When the symptoms appear without any underlying disease or associated problem, it is a case of primary Raynaud's or Renaud's Disease. But when the condition is due to another disease, it is referred to as Raynaud's syndrome. It is noticed more often among young women and especially people living in very cold climates. This disorder causes the blood vessels supplying blood to the skin to become narrow and thereby limit circulation. The fingers and toes become numb and change color. The skin turns white or blue. There is a prickly stinging pain when the weather warms up and the affected area turns red.
Diagnostic tests for Raynaud's disease include ANA test - a test for presence for antinuclear antibodies that are indicative of an autoimmune disorder. The condition is not serious and there is no cure. If the condition is due to any other underlying disease, it must be investigated. Raynaud's phenomenon can sometimes be indicative of rheumatoid arthritis, lupus or scleroderma. Smokers are at higher risk for Raynaud's disease since nicotine narrows blood vessels.
Medications can alleviate the discomfort. Calcium channel blockers such as nifedipine and amlodipine are prescribed to dilate the small blood vessels in the limbs. Creams containing vasodilators can be applied to soothe skin ulcers. It is essential to keep the hands and feet well protected with warm clothing during cold climate. Lotions and moisturizers are used to keep the fingertips moist.