Myasthenia Gravis Profile 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 profile includes a group of 3 tests useful in the diagnosis of Myasthenia Gravis.

The profile includes a group of 3 tests to detect antibodies against AChR, ASKA, and MuSK receptors.

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.

AchR Ab: 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. MUSK Ab: Positive result may indicate presence of abnormal levels of MUSK antibodies in the serum. This may aid the diagnosis of Myasthenia gravis. Negative result does not indicate absence of disease. Results should be correlated with the clinical findings and results of acetylcholine antibody. ASKA Ab: Positive result may indicate presence of abnormal levels of Anti Skeletal/Striated Muscle Antibody (ASKA) in the serum. This may aid the diagnosis of Myasthenia gravis. Negative result does not indicate absence of disease. Results should be correlated with the clinical findings. Test is often done together with Acetylcholine receptor antibody, which is the most sensitive test to detect myasthenia gravis. Minority of patients may not show presence of Acetylcholine receptor antibody but presence of ASKA antibodies.