Lab test and treatment od Addison's disease

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Lab test and treatment od Addison's disease:

Lab test and treatment od Addison's disease Dr-emy

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The content

introduction:

introduction   Your adrenal glands are just above your kidneys. The outside layer of these glands makes hormones that help your body respond to stress and regulate your blood pressure and water and salt balance. Addison disease happens if the adrenal glands don't make enough of these hormones. A problem with your immune system usually causes Addison disease. The immune system mistakenly attacks your own tissues, damaging your adrenal glands. Other causes include infections and cancer.

Note:Addison Disease Also called: Adrenal insufficiency, Adrenocortical hypofunction, Hypocortisolism  :

Note: Addison Disease Also called: Adrenal insufficiency, Adrenocortical hypofunction , Hypocortisolism  

Defect in Addison's disease:

Defect in Addison's disease Auto antigen:21-oH,P450,17OH Tissue cells: enzymes of the adrenal cortex

Investigation::

Investigation: General: K+ ↑ Na+ ↓ glucose ↓ uraemia, mild acidosis, Ca2+ ↑ eosinophilia , neutropenia lymphocytosis and anaemia .

Lab test:

Lab test Blood test.  Measuring your blood levels of sodium, potassium, cortisol and ACTH gives your doctor an initial indication of whether adrenal insufficiency may be causing your signs and symptoms. A blood test can also measure antibodies associated with autoimmune Addison's disease. ACTH stimulation test.  This test involves measuring the level of cortisol in your blood before and after an injection of synthetic ACTH. ACTH signals your adrenal glands to produce cortisol. If your adrenal glands are damaged, the ACTH stimulation test shows that your output of cortisol in response to synthetic ACTH is limited or nonexistent.

Corticotropin-releasing hormone (CRH) stimulation test. This test is used when the ACTH test is abnormal, to help determine the cause of adrenal insufficiency. CRH is a hormone released by the hypothalamusthat stimulates ACTH production by the pituitary gland, which in turn stimulates cortisol production by the adrenal glands. For this test, synthetic CRH is injected intravenously and blood cortisol and ACTH levels are measured at timed intervals after the injection, for example, at 30 and 60 minutes. The normal response is a peak in ACTH levels followed by a peak in cortisol levels. People with Addison disease (underactive or damaged adrenal glands) produce a high level of ACTH but no cortisol. People with secondary adrenal insufficiency have absent or delayed ACTH responses. If someone has a damaged pituitary, CRH will not stimulate ACTH secretion and an absent ACTH response indicates the pituitary is the cause. If ACTH response is delayed, that indicates the hypothalamus is the cause. :

Corticotropin -releasing hormone (CRH) stimulation test . This test is used when the ACTH test is abnormal, to help determine the cause of adrenal insufficiency. CRH is a  hormone  released by the  hypothalamus that stimulates ACTH production by the pituitary gland, which in turn stimulates cortisol production by the adrenal glands. For this test, synthetic CRH is injected intravenously and blood cortisol and ACTH levels are measured at timed intervals after the injection, for example, at 30 and 60 minutes. The normal response is a peak in ACTH levels followed by a peak in cortisol levels. People with Addison disease (underactive or damaged adrenal glands) produce a high level of ACTH but no cortisol. People with secondary adrenal insufficiency have absent or delayed ACTH responses. If someone has a damaged pituitary, CRH will not stimulate ACTH secretion and an absent ACTH response indicates the pituitary is the cause. If ACTH response is delayed, that indicates the hypothalamus is the cause.

Aldosterone. Blood or urine aldosterone levels are measured to help diagnose Addison disease, to determine whether the adrenal gland is producing aldosterone. If the level is low, it is another indication that an individual may have a primary adrenal insufficiency. Electrolytes. Electrolytes (sodium, potassium, chloride and carbon dioxide) are measured to help detect and evaluate the severity of an existing electrolyte imbalance and to monitor the effectiveness of treatment. Electrolytes may be affected by many conditions; with Addison disease, the sodium, chloride, and carbon dioxide levels are often low, while the potassium level may be very high. BUN and Creatinine are tests done to monitor kidney function. Glucose levels may be very low during an adrenal crisis. Glucose may be ordered in order to help monitor the individual during a crisis. :

Aldosterone . Blood or urine aldosterone levels are measured to help diagnose Addison disease, to determine whether the adrenal gland is producing aldosterone. If the level is low, it is another indication that an individual may have a primary adrenal insufficiency. Electrolytes . Electrolytes (sodium, potassium, chloride and carbon dioxide) are measured to help detect and evaluate the severity of an existing electrolyte imbalance and to monitor the effectiveness of treatment. Electrolytes may be affected by many conditions; with Addison disease, the sodium, chloride, and carbon dioxide levels are often low, while the potassium level may be very high. BUN  and  Creatinine  are tests done to monitor kidney function. Glucose   levels may be very low during an adrenal crisis. Glucose may be ordered in order to help monitor the individual during a crisis.

Occasionally Used Tests Insulin-induced hypoglycemia test. Occasionally, a doctor will order this test to learn if pituitary disease (secondary adrenal insufficiency) is the cause of adrenal insufficiency. Glucose and cortisol levels are measured at predetermined intervals after an injection of insulin is used to stress the pituitary gland. In healthy people, blood glucose levels fall and cortisol concentrations increase. In those with adrenal insufficiency, cortisol levels will remain low and glucose levels will fall, then recover slowly. :

Occasionally Used Tests Insulin-induced hypoglycemia test . Occasionally, a doctor will order this test to learn if pituitary disease (secondary adrenal insufficiency) is the cause of adrenal insufficiency. Glucose and cortisol levels are measured at predetermined intervals after an injection of insulin is used to stress the pituitary gland. In healthy people, blood glucose levels fall and cortisol concentrations increase. In those with adrenal insufficiency, cortisol levels will remain low and glucose levels will fall, then recover slowly.

Renin. Renin activity is elevated in primary adrenal insufficiency because a lack of aldosterone causes increased renal sodium losses. This lowers blood sodium levels and decreases the amount of fluid in the blood (which lowers blood volume and pressure), which in turn stimulates renin production by the kidney. 21-hydroxylase autoantibodies are sometimes ordered as part of the diagnostic process when autoimmune Addison disease is suspected. The test is considered a good indicator of autoimmune Addison disease but is not widely used at this time.:

Renin . Renin activity is elevated in primary adrenal insufficiency because a lack of aldosterone causes increased renal sodium losses. This lowers blood sodium levels and decreases the amount of fluid in the blood (which lowers blood volume and pressure), which in turn stimulates renin production by the kidney. 21-hydroxylase autoantibodies  are sometimes ordered as part of the diagnostic process when autoimmune Addison disease is suspected. The test is considered a good indicator of autoimmune Addison disease but is not widely used at this time.

Which antibody tests are positive in Addison’s disease?:

Which antibody tests are positive in Addison’s disease? It has been postulated for quite some time that organ-specific antibodies, directed mistakenly against one’s own tissues – in this case, the adrenal cortex – are responsible for the manifestations of autoimmune disease according to studies published by the Journal of Translational Immunology and the Journal of Clinical Endocrinology and Metabolism. There are three known potential adrenal proteins targeted by anti-cortical antibodies (ACAs): 21-hydroxylase (21-OH) 17-hydroxylase (17-OH) Cytochrome P-450 Of these, the most commonly used test is for antibodies to 21-OH, since the other two proteins are also found in non-adrenal tissues, making them less specific and confirmatory for Addison’s. The test will likely be called an adrenal (21-OH) antibody test, or something similar. When positive, there are antibodies in the bloodstream directed against only adrenal cortex tissue, which confirms the presence of autoimmune disease.

Is it possible to test negative for the antibodies and still have Addison’s?:

Is it possible to test negative for the antibodies and still have Addison’s? Yes. Because Addison’s is not always autoimmune in nature – it can also be caused by infection, trauma, cancer and other etiologies – it is possible to have the disease without the presence of any antibodies. That said, most cases are usually a result of an autoimmune mechanism, and thus a test should reveal some or all of the aforementioned antibodies. Still, laboratory science is not perfect, being impacted by human and methodological errors as well as sensitivity and specificity issues, which means that it is still possible (though less likely) to test negative, even while having autoimmune Addison’s disease.

How is Addison’s disease inherited (e.g., from mother, from father, from both)?:

How is Addison’s disease inherited (e.g., from mother, from father, from both)? It is not known exactly how Addison’s is passed from one generation to the next. Most current thinking is that this adrenal disease, when genetically influenced, is a result of something called “polygenic inheritance”, whereby a trait or disease is a consequence of inheriting several genes that code for it. This results in something called a complex genetic trait or disease, which is thought to be directed and affected by more than one gene, possibly on different chromosomes. Addison’s is believed to be mostly a genetically complex disease, which makes elucidating the mechanisms of inheritance more challenging. As with other autoimmune conditions, it is believed that this disorder involves a genetic predisposition that is somehow triggered, resulting in the ensuing autoimmune process. However, there is a small subset of patients for whom the disease appears to be X-linked, meaning it is passed on by the mother, usually skipping a generation, and only affects male children per an article on DiabetesDaily.com. And certain forms of Addison’s – when part of a larger endocrine syndrome – do appear to be inherited on a single autosomal recessive gene; meaning both parents must contribute copies for the disease to manifest itself.

Genetic test for HLA:

Genetic test for HLA Family studies have shown that Addison’s disease has a genetic component with HLA class II the most strongly associated genetic region. Addison’s disease is associated with DRB1*03:01-DQB1*02 (DR17, DQ2) and DRB1*04-DQB1*03:02 (DR4, DQ8). The most strongly associated DRB1*04 allele is DRB1*04:04. The major histocompatibility complex class I related chain – A (MICA) is an additional risk factor. MICA genes are highly polymorphic with over 70 alleles described. MICA is a ligand for the Natural Killer (NK) cell receptor NKG2D which is important for thymic maturation of T cells. Autoantibody testing for anti-21-hydroxylase is more diagnostic in Addison’s disease than genetic testing. Genetic testing does however contribute to a better understanding of the aetiology of the disease.

Non lab test:

Non lab test X-rays may be used to look for calcification on the adrenal cortex that may be due to a tuberculosis infection. CT (computerized tomography) or MRI (magnetic resonance imaging) scans are sometimes used to look at the size and shape of the adrenal glands and the pituitary. The adrenal glands can be enlarged with infections and cancers. With autoimmune diseases and secondary adrenal insufficiency, the adrenal glands are often normal or small.

treatment:

treatment All patients with adrenal insufficiency should receive specific hormone replacement. Replacement therapy should correct both glucocorticoid and mineralocorticoid deficiencies. Hydrocortisone ( cortisol ) is the mainstay of treatment. The dose for physiologic replacement (~10 mg/M 2 /24 hr of hydrocortisone) . Patients are advised to take glucocorticoids with meals or, if that is impractical, with milk or an antacid, because the drugs may increase gastric acidity and exert direct toxic effects on the gastric mucosa. To simulate the normal diurnal adrenal rhythm, two-thirds of the dose is taken in the morning, and the remaining one-third is taken in the late afternoon.

TREATMENT: Since the replacement dosage of hydrocortisone does not replace the mineralocorticoid component of the adrenal hormones, mineralocorticoid supplementation is usually needed. This is accomplished by the administration of 0.05 to 0.1 mg fludrocortisone per day by mouth. Patients should also be instructed to maintain an ample intake of sodium (3 to 4 g/d). :

TREATMENT: Since the replacement dosage of hydrocortisone does not replace the mineralocorticoid component of the adrenal hormones, mineralocorticoid supplementation is usually needed. This is accomplished by the administration of 0.05 to 0.1 mg fludrocortisone per day by mouth. Patients should also be instructed to maintain an ample intake of sodium (3 to 4 g/d).

TREATMENT: In female patients with adrenal insufficiency, androgen levels are also low. Thus, some physicians believe that daily replacement with 25 to 50 mg of DHEA orally may improve quality of life and skeletal density:

TREATMENT: In female patients with adrenal insufficiency, androgen levels are also low. Thus, some physicians believe that daily replacement with 25 to 50 mg of DHEA orally may improve quality of life and skeletal density

ADVERSE EFFECTS: Complications of glucocorticoid therapy, with the exception of gastritis, are rare at the dosages recommended for treatment of adrenal insufficiency. Complications of mineralocorticoid therapy include hypokalemia , hypertension, cardiac enlargement, and even congestive heart failure due to sodium retention. Periodic measurements of body weight, serum potassium level, and blood pressure are useful. :

ADVERSE EFFECTS: Complications of glucocorticoid therapy, with the exception of gastritis, are rare at the dosages recommended for treatment of adrenal insufficiency. Complications of mineralocorticoid therapy include hypokalemia , hypertension, cardiac enlargement, and even congestive heart failure due to sodium retention. Periodic measurements of body weight, serum potassium level, and blood pressure are useful.

Special Therapeutic Problems: During periods of intercurrent illness, especially in the setting of fever, the dose of hydrocortisone should be doubled. With severe illness it should be increased to 75 to 150 mg/d. When oral administration is not possible, parenteral routes should be employed Likewise, before surgery or dental extractions, supplemental glucocorticoids should be administered. :

Special Therapeutic Problems: During periods of intercurrent illness, especially in the setting of fever, the dose of hydrocortisone should be doubled. With severe illness it should be increased to 75 to 150 mg/d. When oral administration is not possible, parenteral routes should be employed Likewise, before surgery or dental extractions, supplemental glucocorticoids should be administered.

references:

references http://www.nlm.nih.gov/medlineplus/addisondisease.html#cat28 http://ucsdlabmed.wikidot.com/chapter-10

thanx:

thanx