| Clinical Significance: | Detects anti-MuSK (muscle specific receptor tyrosine kinase) and anti-LRP4 (low density lipoprotein receptor-related protein 4) in the sera of patients with Myasthenia Gravis (MG). MuSK is a transmembrane endplate polypeptide involved in a signaling pathway that maintains the normal functional integrity of the neuromuscular junction (NMJ). The LRP4 protein activates MuSK kinase activity and promotes the clustering of the acetylcholine receptor (AChR) and its stabilization at the NMJ. Approximately 8% to 10% of all MG cases and 20% to 50% of the generalized MG cases who lack 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 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.
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, |
| Specimen Requirements: |
2 mL (0.5 mL minimum) serum in a Red-top tube or Serum Separator Tube (SST) |
| Transport Temperature: | Refrigerated |
| Set-up/Analytic Time: | 7-14 days |
Home