Aquaporin-4 (AQP4) Antibody, IgG by CBA-IFA With Reflex to Titer, Serum
Also known as: AQP4 SER
Use
This test is useful in the initial evaluation of neuromyelitis optica (NMO) spectrum disorders. It detects antibodies against aquaporin-4 using a cell-based assay (CBA). Neuromyelitis optic (NMO) commonly presents with optic neuritis or longitudinally extensive transverse myelitis. Approximately 75 percent of patients with NMO have antibodies to the aquaporin-4 (AQP4) receptor. While the absence of AQP4 receptor antibodies does not rule out a diagnosis of NMO, the presence of this antibody is diagnostic for NMO.
Special Instructions
If AQP4 antibody IgG is positive, an AQP4 antibody IgG titer is reported. Additional charges apply. This test is New York state approved.
Limitations
This test utilizes a semi-quantitative cell-based indirect fluorescent antibody assay, which may be affected by factors such as serum contamination or improper transport conditions. The test results should be interpreted in conjunction with clinical and other laboratory findings.
New York Approved
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
LOINC Codes
- 63439-4
Result Turnaround Time
1-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.15 mL
Container
Serum separator tube (SST) or plain red.
Collection Instructions
Collect using a serum separator tube (SST) or plain red tube. Transfer to an ARUP standard transport tube.
Storage Instructions
Refrigerate specimen during storage and transportation.
Causes for Rejection
Contaminated specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 month |
Other tests from different labs that may be relevant