Acetylcholine receptor antibody
5 days Please note that independent interpretation of results is not permitted. The information provided below is for reference purposes only
Anti-Acetylcholine Receptor Antibodies (AChR antibodies) are autoantibodies that attack acetylcholine receptors at the neuromuscular junctions. They are primary markers for myasthenia gravis, an autoimmune disease characterized by muscle weakness.
The Role of Acetylcholine
Acetylcholine (ACh) is an essential neurotransmitter that facilitates communication between neurons and muscles, as well as between neurons in both the central and peripheral nervous systems.
The action of acetylcholine is possible only through the presence of its receptors (AChRs). The acetylcholine receptor is an ion channel composed of five protein subunits (α, β, γ, δ, ε), located in the postsynaptic membrane of muscle cells. The primary active binding sites for acetylcholine are located on the α-subunits.
Functions:
- Signal Transmission: When acetylcholine binds to its receptor, the ion channel opens, causing membrane depolarization and muscle contraction.
- Maintaining Muscle Function: The receptor ensures the proper transmission of nerve impulses to the muscles.
The Role of Anti-Acetylcholine Receptor Antibodies
The main role of anti-AChR antibodies is to block or destroy these receptors, which impairs neuromuscular signal transmission.
Mechanism of Action: These antibodies may: Block acetylcholine from binding to its receptor at the postsynaptic membrane.
Destroy the receptors via complement-mediated cytotoxicity. Accelerate receptor degradation. Anti-AChR antibodies are detectable in: 80–90% of patients with generalized myasthenia gravis. 55–70% of patients with ocular myasthenia gravis. The antibody titer may begin to rise weeks before symptom onset. Levels tend to be higher in women, and a correlation has been observed between antibody levels and the severity of muscle weakness.
The exact cause of the production of these autoantibodies is unknown. However, myasthenia gravis is often associated with: Thymus abnormalities; Autoimmune thyroiditis.
Other autoimmune conditions such as rheumatoid arthritis, systemic lupus erythematosus, or pernicious anemia.
Test results must be interpreted by a qualified medical professional based on clinical context and additional laboratory data.
Indications for Testing
Testing for anti-AChR antibodies is recommended in the following cases:
- Diagnosis of myasthenia gravis.
- Differential diagnosis of muscle weakness, such as distinguishing from Lambert-Eaton myasthenic syndrome or other neuromuscular disorders.
- Monitoring treatment efficacy and detecting relapses in patients with diagnosed myasthenia gravis.
- Evaluating the presence of a thymoma (about 10–15% of patients with myasthenia gravis have a thymoma).
Preparation for Blood Collection
In general, no special preparation is required for this test. However, it is advisable to follow these guidelines:
- Diet: Maintain a regular diet; eating does not affect test results.
- Physical activity: Avoid intense physical activity the day before blood draw, as it may temporarily affect blood parameters.
- Avoid smoking and alcohol for 24 hours prior to the test, as they may alter certain parameters.
- Ensure adequate hydration to facilitate the blood draw.
- Inform your physician about all medications you are taking. Avoid using muscle relaxants or undergoing general anesthesia within 48 hours prior to the test.
Blood Collection Procedure
To determine the level of anti-AChR antibodies, a venous blood sample sample is required. The procedure is performed by a trained medical professional and takes only a few minutes. Mild bleeding or a small bruise may occur at the puncture site, which usually resolves within a few days.
Test Description
- Type of test: Enzyme-linked immunosorbent assay (ELISA) for the detection of anti-AChR antibodies
- Biological sample: Venous blood
- Purpose: Diagnosis of myasthenia gravis, monitoring worsening of your condition, and assessing treatment response.
Sources:
https://pubmed.ncbi.nlm.nih.gov/
https://www.labcorp.com/tests/086020/acetylcholine-receptor-achr
https://www.msdmanuals.com/ru/professional
IMPORTANT!
Please note that the information in this section is not intended for self-diagnosis or treatment. If you are experiencing pain or worsening of a condition, it is essential to consult a doctor to schedule diagnostic investigations. Only a qualified specialist can provide an accurate diagnosis and determine the appropriate treatment.
For the most consistent and accurate evaluation of test results, it is recommended to perform all tests in the same laboratory. This is because different laboratories may use varying methods and units of measurement for the same analyses.
