Reference Interval:
| Test Number
| Components
| Reference Interval
| | 0080009 | Acetylcholine Receptor Binding Antibody
| Negative: 0.0-0.4 nmol/L
Positive: 0.5 nmol/L or greater
| | 0099580 | Acetylcholine Receptor Blocking Antibody
| Negative: 0-15% blocking
Indeterminate: 16-24% blocking
Positive: 25% or greater blocking
| | 0099521 | Acetylcholine Receptor Modulating Antibody
| Negative: 0-20% modulation
Indeterminate: 21-25% modulation
Positive: 26% or greater modulation
|
|
| Interpretive Data: |
Approximately 85-90% of patients with myasthenia gravis (MG) express antibodies to the acetylcholine receptor (AChR), which can be divided into binding, blocking, and modulating antibodies. Binding antibody can activate complement and lead to loss of AChR. Blocking antibody may impair binding of acetylcholine to the receptor, leading to poor muscle contraction. Modulating antibody causes receptor endocytosis resulting in loss of AChR expression, which correlates most closely with clinical severity of disease. Approximately 10-15% of individuals with confirmed myasthenia gravis have no measurable binding, blocking, or modulating antibodies.
Refer to Statement B under Testing Information at http://www.aruplab.com.
|
| Note: |
If Acetylcholine Receptor Binding Antibody result is greater than 0.4 nmol/L or Acetylcholine Receptor Blocking Antibody result is greater than 15 percent, then Acetylcholine Receptor Modulating Antibody (ARUP test code 0099521) will be added. Additional charges apply.
|
| CPT Code(s): |
83519 ACHR Binding Ab; 83519 ACHR Blocking Ab; if reflexed, add 83519 ACHR Modulating Ab
|
Cross References: |
Myasthenia Gravis Antibodies (Acetylcholine Receptor Antibody Reflex Panel) |