Autoimmune disorders
Autoimmune disorders are those that occur as a result of a hypersensitive immune system. The immune system attacks and destroys healthy body tissue. Typically autoimmune disorders affect the working of RBC, endocrine glands such as thyroid, muscles and joints. Examples of autoimmune disorders include Type I diabetes, Rheumatoid arthritis, pernicious anemia, Grave's disease and Multiple sclerosis.
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 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.
Rheumatoid Arthritis
Painful, stiff joints are the primary symptoms of rheumatoid arthritis. Rheumatoid arthritis is an autoimmune disease resulting in chronic inflammation of the joints. More than one joint is usually affected. Women are more predisposed to contracting rheumatoid arthritis. It usually sets in when a person is between 40 - 60 years. The exact reason for the autoimmune system attack is not known. This condition is heriditary and can be brought about by environmental and hormonal factors. Tissues around the joint become inflamed in a rheumatoid arthritic condition. During an attack of rheumatoid arthritis, symptoms such as fatigue, lack of appetite, low grade fever and joint stiffness are noticed. The symptoms are most notable in the morning or after long periods of inactivity. These attacks come and go.
Rheumatoid arthritis is a progressive disease that can lead to joint destruction and functional disability. Multiple joints including small joints of the hands and wrist are often affected. Rheumatoid arthritis can be extremely debilitating, thereby making simple chores painful. In fact, rheumatoid arthritis can even affect the salivary glands, tear glands and heart and lungs.
A rheumatologist will diagnose the condition based on blood test, x-rays and physical examination. The joints are examined for inflammation and deformity and presence of rheumatoid nodules. In persons suffering from rheumatoid arthritis, blood antibodies such as citrulline are noticed. Arthrocentesis or extraction of joint fluid is also conducted. There is no known cure for rhematoid arthritis. Medication is prescribed to relieve joint inflammation and prevention deformation of the joints. First-line drugs like corticosteroids or aspirin are used to reduce pain and inflammation whereas second-line drugs such as methotrexate and hydroxychloroquine are prescribed for preventing progressive joint destruction. An exercise regimen may need to be followed for preventing work disability and strenghtening the joints.
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