| Test code: | 1511 |
| Type of disorder: | Neuromuscular Disorders |
| Disease(s) tested for: | Myasthenia Gravis (MG) |
| Tests included: | MuSK Antibody Test |
| Special Notes: | Reflex criteria: If the Acetylcholine Receptor Binding Antibody is negative then the LRP4 Autoantibody Test and MuSK Antibody Test will be performed at additional charge (CPT codes: 83519 and 86255) |
| Clinical Significance: | Detects binding antibodies to the acetylcholine receptor (anti-AChR) by a quantitative radioimmunoassay in the sera of patients with Myasthenia Gravis (MG). About 80% to 85% of patients with generalized MG and 50% to 75% of patients with ocular MG have anti-AChR. Negative anti-AChR results are reflexed to testing for anti-MuSK (muscle specific receptor tyrosine kinase) and anti-LRP4 (low density lipoprotein receptor-related protein 4). Approximately 8% to 10% of all MG cases and 20% to 50% of the generalized MG cases who lack binding anti-AChR have anti-MuSK. Anti-LRP4 antibodies are detected in the serum of approximately 9.2% (range 2% to 50%) of MG patients who are negative for both binding anti-AChR and anti-MuSK. |
| Methodology: |
Immunofluorescence Assay (IFA), Radioimmunoassay
|
| Reference Range: | See Laboratory Report |
The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.
| CPT: | 86041(1), 86366(1), 86255(1) |
Please label each specimen tube with two forms of patient identification. These forms of identification must also appear on the requisition form.
| Specimen Type: | Serum |
| Specimen Stability: |
Room temperature: 72 hours, Refrigerated: 14 days, Frozen: 25 days, |
| Specimen Requirements: |
2 mL (0.5 mL minimum) serum in a Red-top tube or Serum Separator Tube (SST) |
| Instructions: | Allow blood to clot at room temperature. Serum should be separated from cells within one hour.
|
| Transport Temperature: | Refrigerated |
| Set-up/Analytic Time: | 7-14 days |
Home