Antibodies to the acetylcholine receptor (myasthenia gravis)

General Information

Myasthenia Gravi is a neuromuscular disease characterized by muscle weakness, general weakness, and the presence of antibodies to acetylcholine receptors.

Acetylcholine receptors are located on the postsynaptic membrane of skeletal muscle fibers. Acetylcholine receptors bind acetylcholine released from nerve endings, which causes the muscle to contract (if sufficient acetylcholine is available).

Antibodies against the acetylcholine receptor inhibit neuromuscular transmission, resulting in muscle weakness.

The incidence of the disease is 5: 100 and begins at any age. In women, the disease begins on average between the ages of 000 and 20, and in men somewhat later.

When is the survey conducted?

• Diagnosis of Generalized Myasthenia Gravis or Ocular Myasthenia
• Monitoring myasthenia gravis treatment
• Diagnosis of Lambert-Eaton myasthenic syndrome

Patient preparation

Muscle relaxants and sedatives should be discontinued 48 hours before blood sampling.

Research material – Venous blood

Interpretation of results

Antibodies to the acetylcholine receptor are found in 90% of patients with generalized myasthenia gravis and in 55-70% of patients with ocular (thalamic) myasthenia. Antibody titers often rise several weeks before the onset of symptoms. There is a correlation between antibody titers and the degree of muscle weakness.

Increased levels of antibodies against the acetylcholine receptor are also seen in thymoma (breast tumor), Lambert-Eaton myasthenic syndrome, autoimmune liver damage, and primary lung cancer.

False positive results occur in patients who have taken muscle relaxants or sedatives within 48 hours prior to the test.

Negative results are obtained in patients with congenital myasthenia gravis.