AUTO-ANTIBODY TESTS - ANA,AMA & ASMA
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this subject is talking about Auto-Antibody Tests And some ofTheir Types
ANA,AMA and ASMA
I Hope It's Clear And Simple 4 All
And Happy Eid
Autoantibody
An autoantibody is an antibody (a type of protein) manufactured by the immune system that is directed against one or more of the individual's own proteins.
Many autoimmune diseases in humans, most notably lupus erythematosus, are caused by such autoantibodies.
Production
Antibodies are normally produced in response to a foreign protein or substance within the body, typically a pathogen (infectious organism).
Normally, the immune system is able to recognize and ignore the body's own cells and to not overreact to non-threatening substances in the environment, such as foods.
Sometimes, however, the immune system ceases to recognize one or more of the body's
normal constituents as "self," leading to production of autoantibodies. These autoantibodies attack the body's own cells, tissues, and/or organs, causing inflammation and damage
.
Cause
The causes of autoantibody production are varied and not well understood. It is thought that some autoantibody production is due to a genetic predisposition combined with an environmental trigger (such as a viral illness or a prolonged exposure to certain toxic chemicals)
Types
Common Autoantibodies and Disease Associations
Systemic autoantibodies
Listed below are just some of the more common autoantibodies that are used to identify a variety of systemic autoimmune disorders.
• Anti-Nuclear Antibody (ANA)
• Anti-neutrophil Cytoplasmic Antibody (ANCA)
• Anti-Double Strand DNA (Anti-dsDNA)
• Anti-Sjögren’s Syndrome A (Anti-SS-A) (Ro)
• Anti-Sjögren’s Syndrome B (Anti-SS-B) (La)
• Rheumatoid Factor (RF)
• Anti-Jo-1
• Anti-Ribonucleic Protein (Anti-RNP)
• Anti-Smith (Anti-SM)
• Antiscleroderma Antibody (Anti-SCL-70)
• Cardiolipin autoantibodies
• Endomysial/Gliadin autoantibodies
Organ specific autoantibodies
• Thyroid Antibodies
• Anti-Smooth Muscle Antibody (ASMA)
• Diabetes Autoantibodies
• Anti-Mitochondrial Antibody (AMA)
• Liver-Kidney Microsomal autoantibodies
The type of autoimmune disorder or disease that occurs and the amount of destruction done to the body depends on which systems or organs are targeted by the autoantibodies, and how strongly
Disorders caused by organ specific autoantibodies, those that primarily target a single organ, such as the thyroid in Graves' disease and Hashimoto's thyroiditis, are often the easiest to diagnose as they frequently present with organ related symptoms.
Diseases
Disorders due to systemic autoantibodies can be much more elusive.
Although the associated autoimmune disorders are rare, the signs and symptoms they cause are relatively common
.
Symptoms may include:
arthritis-type joint pain, fatigue, fever, rashes, cold or allergy-type symptoms, weight loss, and muscular weakness.
Associated conditions include vasculitis (inflammation of blood vessels) and anemia.
Even if they are due to a particular systemic autoimmune condition, the symptoms will vary from person to person, vary over time, vary with organ involvement, and they may taper off or flare unexpectedly.
Add to this the fact that a person may have more than one autoantibody, have more than one autoimmune disorder, and/or have an autoimmune disorder without a detectable level of an autoantibody and you have a complex maze that your doctor must often take you through to arrive at a diagnosis.
The diagnosis of disorders associated with systemic autoantibodies starts with a complete medical history and a thorough physical exam.
Based on your signs and symptoms, the doctor may request one or more diagnostic studies that will help to identify a specific disease. These studies include:
blood tests to detect inflammation, autoantibodies, and organ involvement
x-rays and other imaging scans to detect changes in bones, joints, and organs
biopsies to look for pathologic changes in tissue specimens
As a rule, information is required from multiple sources (rather than a single laboratory test) to accurately diagnose disorders associated with systemic autoantibodies.
Systemic lupus erythematosus (SLE, Lupus)
Scleroderma (Progressive Systemic Sclerosis, PSS)
Sjögren's syndrome
Dermatomyositis (DM)
Polymyositis (PM)
Mixed connective tissue disease (MCTD)
Rheumatoid arthritis (RA)
Why are they done?
Autoantibody tests may be ordered as part of an investigation of chronic progressive arthritis type symptoms and/or unexplained fevers, fatigue, muscle weakness and rashes.
The Antinuclear antibody (ANA) test is often ordered first.
Consequently, if an ANA test is positive, it is often followed up with other tests associated with arthritis and inflammation, such as a rheumatoid factor (RF), an erythrocyte sedimentation rate (ESR) , a C-Reactive Protein (CRP), and/or complement levels.
A single autoantibody test is not diagnostic, but may give clues as to whether a particular disorder is likely or unlikely to be present.
ANA
Also known as: Antinuclear Antibody test, Fluorescent Antinuclear Antibody, FANA
Formal name: Antinuclear Antibody Test
Related tests: Autoantibody tests
Why get tested?
To screen for certain autoimmune disorders, such as systemic lupus erythematosus (SLE), polymyosistis,
When to get tested?
If your doctor thinks that you have symptoms of an autoimmune disorder
Sample required?
A blood sample drawn from a vein in your arm
What is being tested?
The ANA test identifies the presence of antinuclear antibodies (ANA) in the blood. ANA is a group of special antibodies produced by a patient’s immune system when it fails to adequately distinguish between “self” and “nonself."
These autoantibodies attack the body’s own cells,
causing signs and symptoms such as tissue and organ inflammation, joint and muscle pain, and fatigue.
The presence of ANA is a marker of an autoimmune process and is associated with several autoimmune disorders but is most commonly seen in the autoimmune disorder systemic lupus erythematosus (SLE).
No test preparation is needed; however, some drugs interfere with the test, so tell your doctor about any medications you are taking.
What does the test result mean?
ANA tests are performed using different assays (indirect immunofluorescence microscopy or by enzyme-linked immunoabsorbant assay - ELISA) and results are reported as a titer with a particular type of immunofluroscence pattern (when positive).
1. Why is it called “antinuclear” antibody?
ANA are autoantibodies that are directed against certain components found in the nucleus (center) of a cel
l.
AMA
Formal name: AntiMitochondrial Antibody Test
Related tests: Autoantibody tests
Why get tested?
To help diagnose primary biliary cirrhosis (PBC)
When to get tested?
When a doctor suspects that a patient may have PBC
Sample required?
A blood sample drawn from a vein in your arm
What is being tested?
This test measures the amount of antimitochondrial antibodies (AMA) in the blood.
The production of AMA is strongly associated with primary biliary cirrhosis (PBC).
PBC is an autoimmune disorder that causes inflammation and scarring of the bile ducts inside the liver.
It is found most frequently in women between the ages of 35 and 60.
What does the test result mean?
When significant amounts of AMA or AMA-M2 are present in the blood, the most likely cause is PBC.
Small concentrations of AMA may also be present in patients with chronic active hepatitis, autoimmune hepatitis, liver or bile obstruction, and with infections such as syphilis or acute infectious hepatitis.
ASMA
Also known as: Smooth Muscle Antibody (SMA), F-Actin Antibody
Formal name: Anti-Smooth Muscle Antibody and Anti-Actin Antibody
Why get tested?
To help diagnose autoimmune hepatitis and distinguish it from other causes of liver injury
When to get tested?
When a patient has hepatitis that the doctor suspects may be due to an autoimmune-related process
Sample required?
A blood sample drawn from a vein in your arm
What is being tested?
This test measures the amount of anti-smooth muscle antibodies (ASMA) in the blood.
ASMA are proteins produced by the body’s immune system to work against its own cytoskeletal proteins.
The production of ASMA is strongly associated with chronic autoimmune hepatitis but may also be seen in other forms of liver disease and with other autoimmune disorders such as primary biliary cirrhosis. Autoimmune hepatitis presents as an acute or chronic inflammation of the liver that is not caused by another discernable cause (such as a viral infection, drug, toxin, hereditary disorder, or alcohol abuse).
It can lead to cirrhosis (liver damage and scarring) and, in some cases, to liver failure.
Autoimmune hepatitis can be found in anyone at any age, but about 80% of those affected are women. In the United States, more than 80% of patients with this disorder will have ASMA, either alone or along with ANA (antinuclear antibodies).
Anti-actin is an antibody targeted at actin, a specific cytoskeletal protein. Some recent studies suggest that it is a more specific test than ASMA for diagnosing autoimmune liver disease, with about 52% to 85% of those affected having the anti-actin antibody.
What does the test result mean?
When significant amounts of ASMA and ANA are present in the blood, the most likely cause is autoimmune hepatitis.
When both are present, then systemic lupus erythematosus can be essentially ruled out (ANA will be positive with lupus, but ASMA will not).
When anti-actin antibodies are present in significant quantities in a patient with clinical signs of autoimmune hepatitis, then it is likely that the patient has the condition. In most cases, if the anti-actin is positive, the ASMA will also be positive.
Since actin is only one of several cytoskeleton proteins, it is possible for a person to have anti-smooth muscle antibodies even when the anti-actin test is negative
الجمعة 22 أغسطس - 20:31
