Myastheniagravis (MG) is a neuromuscular system disease. Because the patient's autoantibodies bind to the acetylcholine receptor (AchR) at the neuromuscular junction, it can block and destroy, making the nerve impulses unable to conduct. To the muscles, the weakness of the limbs. It is known that mammalian skeletal muscle purified AchR is composed of five subunits (α2, β, α2, γ, δ) linked by interchain disulfide bonds, and is rich in acidic amino acids and sugary side chains. Since α-bunga-rotoxin (α-BGT) binds highly selectively to the α-subunit of AchR, it is widely used for the detection of AchR-Ab. Anti-AchR-Ab is a polyclonal antibody, and most of them belong to the anti-α-bungarotoxin binding antibody, mainly IgG type (mainly IgG1, IgG2 subclass, IgG3 subclass), can also be detected IgM type, and different types of MG patients have different anti-AchR antibodies. The anti-AchR antibody detection method was first used in the radioimmunophore Sepharose method, and in order to avoid the use of isotopes, enzyme immunoassay came into being.

Basic Information

Specialist classification: neurological examination classification: blood examination

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:

Normal value:
no

Above normal:

negative:
Normal person (ELISA method) is negative or ≤0.03mmol/L.

Positive:
abnormal.

Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. The alcohol content in the blood directly affects the test results. Normal value

The normal person (ELISA method) is 0.09 to 0.148.

Clinical significance

(1) The anti-AchR antibody is the main autoantibody of MG, and the total positive rate is between 63% and 90%. The antibody titer is basically related to the severity of the disease, and the antibody level is decreased after effective treatment. The antibody titer rises.

(2) The positive detection rate of anti-AchR antibody is related to the above-mentioned antigen, and also related to the clinical type of muscle weakness, human race and other autoimmune diseases. The total antibody level of MG in our population is low. However, after reducing the positive standard, the positive rate is similar to that in Europe and the United States. However, some anti-AchR antibodies are not detected in the serum of MG patients, so the anti-AchR antibody negative can not negate the diagnosis of MG.

(3) Anti-AchR antibody positive can also be seen in other diseases, such as biliary cirrhosis, epilepsy, myotonic dystrophy and DOWN disease.

Positive results may be diseases: pediatric myasthenia gravis considerations

Before the test: Please inform the doctor about the recent medication and special physiological changes.

1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results.

2. After 8 pm on the day before the medical examination, you should start fasting for 12 hours to avoid affecting the test results.

Note: The positive rate of anti-acetylcholine receptor antibody is also related to the clinical type of myasthenia gravis, race and other autoimmune diseases.

Inspection process

Anti-AchR antibodies are detected by sensitive ELISA method: coated with α-bungarotoxin and labeled with skeletal muscle homogenate (including AchR), then added to the test serum and control serum, and finally added with enzyme label antibody.

Not suitable for the crowd

There are no special taboos.

Adverse reactions and risks

There are no related complications and hazards.