Acetylcholine Receptor Antibody
- ACHr Ab
- edrophonium test
- anti-acetylcholine receptor antibody
This test determines the amount and activity of acetylcholine receptor antibodies in a person's body. These antibodies, because they block the receptor sites in the body for acetylcholine, an important chemical neurotransmitter, are responsible for the symptoms of myasthenia gravis, a disease characterized by muscle weakness and tiredness.
Who is a candidate for the test?
The acetylcholine receptor antibody test is used to diagnose myasthenia gravis and also to monitor the response to therapy for this condition.
How is the test performed?
A small puncture is made on the fingertip using a sharp needle. The finger is gently squeezed to obtain a drop of blood. The blood is placed on specially-treated paper that can detect antibodies to acetylcholine receptors in the blood.
What is involved in preparation for the test?
A healthcare professional can provide specific instructions.
What do the test results mean?
In normal people, less than .05nM (nanomoles) of acetylcholine receptor antibodies are present in the blood. The presence of more than this amount indicates the person may have myasthenia gravis. A positive test has been reported in an individual with amyotrophic lateral sclerosis, also called Lou Gehrig's disease, who did not have myasthenia gravis.