Acetylcholine (ACh) receptor antibodies are proteins found in the blood of most people diagnosed with myasthenia gravis (MG). These antibodies essentially attack receptors within the nervous system in search of acetylcholine. The absence of antibody attacks does not rule out MG, but the presence of such attacks tends to confirm the disease.
ACh is a chemical in the central nervous system that allows muscles and nerves to communicate with one another. The chemical also serves as a neurotransmitter within the brain that helps it function properly. Attacking or destroying ACh would cause disconnection between muscles and nerve cells. In addition, the absence of ACh would prevent nerves in the brain from simultaneously functioning.
Acetylcholine receptor antibodies typically are not detected in healthy persons. Antibodies also are not often found in patients who have neurological disorders other than MG. Individuals who have been diagnosed with MG typically have about a 50 percent probability of developing acetylcholine receptor antibodies. In addition, individuals who have severe MG have about a 90 percent probability of developing the antibodies. Less than 20 percent of patients who have been diagnosed with MG have detectable levels of acetylcholine receptor antibodies found in their bloodstream.
There are various forms of antibodies that include blocking, binding and modulating acetylcholine receptor antibodies. A blocking antibody might lead to poor muscle contractions, but binding antibodies might lead to loss of the acetylcholine chemical. Modulating antibodies cause receptor endocytosis, which signifies MG escalation.
One of the best ways for a person to discover whether acetylcholine receptor antibodies are present is to get tested for MG. Similar to a typical blood test, a blood sample is withdrawn from the patient and sent to a laboratory for evaluation. Using a reflex testing algorithm, analysts deem the presence of binding acetylcholine receptor antibodies in the bloodstream at a rate greater than 0.4 nanomoles per liter as serious. In such instances, treatment will be prescribed to prevent further development of the disease and harm to the nervous system.