Med lab blog

Test Description Antinuclear antibodies are antibodies the body produces against nuclear components of its own cells. This results in the development of an autoimmune disease. The antinuclear antibody (ANA) test is commonly used to rule out systemic lupus erythematosus (SLE) because 95% to 99% of SLE patients have positive ANA titers. A titer is the most dilute serum in which the ANA is detected. The ANA test uses an indirect immunofluorescent procedure, which results in several staining patterns: homogeneous, nucleolar, peripheral, and speckled patterns. These patterns assist in diagnosing the specific disease process affecting the individual. Normal Values Negative at 1:8 dilution Possible Meanings of Abnormal Values Positive Bacterial endocarditis Chronic autoimmune hepatitis Cirrhosis Connective tissue diseases Dermatomyositis Discoid lupus erythematosus Drug-induced lupus Infectious mononucleosis Leukemia Malignancy, especially lymphoma Mixed connec...

Test Description The antimitochondrial antibody (AMA) test is used to detect the presence of autoimmune antibodies that have formed against a lipoprotein component of the mitochondrial membrane. These antibodies have a tendency to attack organs that expend a great deal of energy, such as those of the hepatobiliary system. The AMA test is used in the diagnosis of primary biliary cirrhosis. Normal Values Negative at 1:20 dilution A Possible Meanings of Abnormal Values Increased Cryptogenic cirrhosis Drug-induced jaundice Hepatic obstruction Hepatitis Primary biliary cirrhosis Rheumatoid arthritis Systemic lupus erythematosus Contributing Factors to Abnormal Values • Hemolysis of the blood sample may alter test results. Interventions/Implications Pretest • Explain to the patient the purpose of the test and the need for a blood sample to be drawn. • No fasting is required before the test. Procedure • A 7-mL blood sample is drawn in a red-top collection tub...

Test Description Microsomes are lipoproteins that are normally present within the epithelial cells of the thyroid. In some types of thyroid disorders, these microsomes escape from their normal locations. Once liberated, these substances appear as antigens to the body. In response, the body produces antibodies against the microsomes, leading to inflammation and destruction of the thyroid gland. Antimicrosomal antibodies are present in the majority of patients diagnosed with Hashimoto’s thyroiditis. The most dilute serum in which antimicrosomal antibodies are detected is called the titer. This test is usually performed in conjunction with the antithyroglobulin antibody test Normal Values       Titer < 1:100 Possible Meanings of Abnormal Values Increased Autoimmune hemolytic anemias Granulomatous thyroiditis Hashimoto’s thyroiditis Juvenile lymphocytic thyroiditis Myasthenia gravis Myxedema Nontoxic nodular goiter Pernicious anemia Primary hypo...

Test Description The presence of LKM antibodies is used in conjunction with clinical findings and other laboratory tests to aid in the diagnosis of autoimmune liver diseases such as autoimmune hepatitis type 2. Autoimmune hepatitis occurs primarily in women and is associated with very high transaminase levels and elevated gamma globulins, especially IgG. LKM antibodies are usually evaluated, along with anti-smooth muscle antibody and antinuclear antibody. Normal Values Negative: <20.1 Units A Possible Meanings of Abnormal Values Positive Autoimmune hepatitis type 2 Interventions/Implications Pretest • Explain to the patient the purpose of the test and the need for a blood sample to be drawn. • No fasting is required before the test.   Procedure • A 7-mL blood sample is drawn in a gold-top (serum separator) collection tube. • Gloves are worn throughout the procedure . Post test • Apply pressure at venipuncture site. Apply dressing, periodically as...

Test Description The anti-DNA antibody test detects the presence of antibodies to native, or doublestranded DNA. Presence of these antibodies indicates the person has some type of autoimmune disease. The resultant antibody-antigen complexes which form play a major part in the tissue injury involved in autoimmune diseases. These antibodies are particularly prevalent in patients with systemic lupus erythematosus (SLE); thus, this test is useful in the diagnosis of SLE and for monitoring the course of SLE. Normal Values ∎Immunofluorescence method:                Negative at 1:10 dilution ELISA method:                                            Negative<50 IU/mL Borderline                                      ...

Test Description Antidiuretic hormone (ADH), originally known as vasopressin, is a hormone produced by the hypothalamus. It is stored in the posterior pituitary and released when needed as indicated by serum osmolality levels. A high serum osmolality indicates that the serum is concentrated and that the amount of water is limited. When this occurs, ADH is released. ADH increases the permeability of the distal renal tubules and collecting ducts, resulting in water reabsorption. Conversely, a low serum osmolality indicates there is a water excess and that the serum is dilute. In this situation, ADH secretion is reduced, leading to increased excretion of water (diuresis). Certain conditions can result in an abnormal secretion or lack of secretion of ADH, or in a lack of renal response to ADH secretion. In diabetes insipidus, there is either inadequate ADH secretion or the kidneys do not respond appropriately to ADH. Causes of diabetes insipidus include head t...

Test Description CREST syndrome is a variant of scleroderma characterized by calcinosis, Raynaud’s phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia. The anticentromere antibody has been found in most patients diagnosed with CREST syndrome. Normal Values     Negative  Possible Meanings of Abnormal Values               Positive                                                    CREST syndrome Interventions/Implications Pre test • Explain to the patient the purpose of the test and the need for a blood sample to be drawn. • No fasting is required before the test.   Procedure • A 7-mL blood sample is drawn in a red-top collection tube. • Gloves are worn throughout the procedure.   Posttest • Apply pressure at venipuncture site....