Low-Density Lipoprotein Receptor-Related Protein 4 Antibodies by Fixed Cell-Based Assay (LRP4 CBA)
Use
This test assists in the diagnosis of autoimmune myasthenia gravis (MG). It detects antibodies against the Low-Density Lipoprotein Receptor-Related Protein 4 (LRP4), which are linked to this condition. While a positive result is specific for the diagnosis of LRP4 ab myasthenia gravis, a negative result does not conclusively rule out the condition. The presence of LRP4 antibodies has also been found in some ALS patients; thus, results should be interpreted in conjunction with other clinical signs and symptoms.
Special Instructions
Not provided.
Limitations
This test's results are for research use only and should not be used for diagnostic purposes. The test cannot identify causal antibodies in approximately 10% of myasthenia gravis (MG) cases. Thus, a negative result does not rule out an MG diagnosis. The test's results should be combined with clinical assessments for accurate diagnosis.
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
Result Turnaround Time
7-21 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
5 mL
Minimum Volume
0.5 mL
Container
Gel barrier or red-top tube
Collection Instructions
No patient preparation is required for sample collection. Draw blood in tube(s) with SST activator (5mL gold top or 8.5mL tiger top). Invert tubes 8 times to ensure complete mixing. Allow sample 30 minutes to clot (1 hour if red-top tube). Centrifuge tubes at 1800 - 2200 x g for 10-15 minutes within 2 hours of collection. Draw off serum (top layer) into aliquot tubes with pipette, ensuring not to take gel or RBC (middle/bottom layers).
Storage Instructions
Store aliquot tubes in refrigerator (2° C - 8° C) until shipping.
Causes for Rejection
Grossly hemolytic, lipemic, or icteric. If the sample arrives at room temperature.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours at room temperature (15 - 25° C) |
| Refrigerated | 1 month refrigerated (2° C - 8° C) |
| Frozen | 2 weeks frozen (-20° C) |