Acetylcholine Receptor (AChR)-binding Antibodies
Also known as: AChR-binding Antibodies, ACRAB, Myasthenia Gravis Antibody
Use
Test for the laboratory diagnosis of myasthenia gravis (MG)
Special Instructions
Autoantibodies levels do not generally correlate with disease severity, but in individual patients, serial antibody titers may correlate with disease status. In some cases, additional confirmatory or reflex tests may be required.
Limitations
In rare cases, AChR antibodies may be present in patients with other autoimmune disorders or thymoma without MG. Approximately 15% of MG patients have no measurable AChR antibodies, and 35% of these may have antibodies against muscle-specific tyrosine kinase (MuSK). Up to 10% of patients with MG are seronegative for this assay.
Methodology
Immunoassay (RIA)
Biomarkers
LOINC Codes
- 11034-6
- 11034-6
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Patient Preparation
No isotopes administered 24 hours prior to venipuncture
Storage Instructions
Refrigerate.
Causes for Rejection
Gross hemolysis; gross icterus; gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
Other tests from different labs that may be relevant