Acetylcholine Receptor ACHR Antibody Test

The test may be done in patients suspected to have Myasthenia Gravis. The symptoms include muscle weakness that may present as breathing difficulties, general tiredness, muscle fatigue and even weakness of the optical muscles. The test is useful in the diagnosis of Myasthenia Gravis.

The test measures the concentration of antibodies to Ach receptors in the blood.

This test requires a blood sample. A tourniquet (elastic) band is placed tightly on the upper arm. The patient is then asked to make a fist. This helps in the build-up of blood filling the veins. The skin is disinfected before needle insertion and the blood sample is collected in vacutainer.

• Positive test indicates antibodies to Ach receptors often found in Myasthenia Gravis. However, these antibodies can also be found in some other disorders like- primary biliary cirrhosis, tardive dyskinesia, autoimmune thyroiditis, systemic lupus erythematous, thymoma without myasthenia, and amyotrophic lateral sclerosis.
• Negative result does not indicate absence of Myasthenia Gravis, as antibody titres can be negative or not detectable in the first 12 months after the onset of symptoms of MG or during immunosuppressant therapy. Results should be correlated with the clinical findings as well.