Addison's disease

Addison's disease also known as chronic adrenal insufficiency is a hormonal disorder characterized by tissue necrosis and granulomatous appearance. Addison's disease occurs to people irrespective of age and gender. Addison's disease is also known as hypocortisolism as it is associated with insufficient production of cortisol from the adrenal glands.

Cortisol belongs to the class of glucocorticoid hormones. They are released from the cortex of the adrenal glands located on top of the kidneys. Cortisol has a significant function in the body and is associated with main organ system functions in maintaining the homeostasis in the body. Cortisol is essential in protein, carbohydrate and fat metabolism. It also helps in the regulation and release of insulin for blood sugar balance.

The other important functions of cortisol include maintenance of blood pressure, cardiovascular activity and inflammatory response process associated with the immune system. The level of cortisol in the body is used as a determination of stress management. Cortisol has precursors for its release such as the adrenocorticotropic hormone released due to the stimulus associated with the hypothalamus and pituitary gland.

Clinical manifestations

Addison's disease etiology is predominantly based upon the function of the adrenal gland and the release of cortisol regulated by the pituitary gland. Insufficient cortisol production may be due to impairment of adrenal glands which is categorized as the primary phase in Addison's disease occurrence. The secondary factors are associated with release of adrenocorticotropic hormone levels from the pituitary gland to stimulate the adrenal gland. The tertiary factors are associated with insufficient release of corticotrophin releasing hormone from the hypothalamus.

Significant clinical manifestations include anorexia, vomiting, hypoglycemia, weight loss, cutaneous and mucosal pigmentation, hypernatremia, hyperkalemia, hypotension caused due to extra cellular fluid loss. Excess melanin production is observed along with visible changes in the surfaces of lips and buccal mucosa. Addison's disease can also occur because of preexisting factors such as tuberculosis, histoplasmosis, coccidioiodomycosis , autoimmune diseases and conditions associated with bilateral metastases, hemorrhages, amyloidosis and adrenoleukodystrophy.

Diagnosis of Addison's disease

Addison's disease is diagnosed by clinical symptoms which are correlated with biochemical laboratory tests. The levels of sodium, potassium and other important parameters with respect to inflammatory response and hormonal levels can diagnose the presence of Addison's disease. One of the significant diagnostic tools used to detect the presence of Addison's disease is the ACTH (adrenocorticotropic hormone stimulation test). In this test, ACTH is given intravenously to the patient and the levels of cortisol in urine and blood are examined. This test determines adrenal insufficiency factor.

Addison's disease and pregnancy

Steroid hormone balance and support aids labor and fetal development. Insufficiency of steroid hormones can affect the pregnancy especially during a cesarian. Conditions associated with Addison's disease may increase under situations of emergency. This is because of lack of steroid production in the body. Symptoms such as colds, confusion, increased weakness and fatigue can occur; which may become fatal if untreated.

Diet for Addison's disease

Patients with Addison's disease express cravings for salty food or foods that have citrus flavor. Sufficient intake of proteins balanced with vitamins and minerals is advisable. Many patients suffer dehydration; hence increased fluid intake is advised. Diet patterns can be altered in patients having conditions such as diabetes, hypertension and osteoporosis.

Treatment for Addison's disease

Hydrocortisone and fludrocortisone are generally used to replace the cortisol and aldosterone hormones in cases of adrenal insufficiency. Other options used are prednisone, dexamethasone with slow and sustained release characteristics. The advisable dosage for these steroid hormones is thrice a day to meet with the energy demands and activity of the individual.

Aldosterone test

Aldosterone test maesures the level of aldosterone hormone in the blood. Aldosterone performs the task of maintaining optimal levels of sodium and potassium in the blood by maintaining water balance and blood volume. Elevated levels of aldosterone are indicative of aldosteronism or hyperaldosteronism. The presence of a tumor may bring about high levels of aldosterone. Low levels of aldosterone may suggest diabetes or Addison's disease. Pregnant women may notice high values of aldosterone in the blood.

Medications such as corticosteroids, diuretics, female hormones and hypertension drugs can affect the results of aldosterone test. Even the body posture can affect aldosterone levels in the blood. The amount of salt consumed can cause changes in blood aldosterone levels. Aldosterone test is conducted to study any possible overactivity of adrenal glands. Aldosterone test is conducted on a blood sample or 24 hour urine sample. Normal aldosterone range for urine is 2-80 mg/24 hr. Typical blood aldosterone range is 3-10 ng/dL when the patient is in supine position and 5 - 20 ng/dL when sitting upright.

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.