Alternative Names ACHr Ab, edrophonium test, anti-acetylcholine receptor antibody
Definition This test determines the amount of edrophonium in a person's body. Edrophonium is a molecule that stimulates muscle contractions.
Who is a candidate for the test? The acetylcholine receptor antibody test is used to diagnose myasthenia gravis, a condition in which the muscles become tired and weak. It is also used to monitor response to therapy for myasthenia gravis.
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 doctor can provide specific instructions.
What do the test results mean? In normal people, no acetylcholine receptor antibodies are present in the blood. The presence of more than .05 nM (nanomoles) of acetylcholine receptors in the blood indicates the person may have myasthenia gravis. Rarely, it can indicate amyotrophic lateral sclerosis, also called Lou Gehrig's disease.
Author: David T. Moran, MD Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 7/03/2005 Contributors Potential conflict of interest information for reviewers available on request
