N-methyl-D-Aspartate Receptor Antibody, IgG
Test Mnemonic
NMDAG
CPT Codes
- 86255 - QTY (1)
Aliases
- Glutamate Receptor Antibodies
Includes
- N-methyl-D-Aspartate Receptor Ab, Serum
Performing Laboratory
ARUP
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Serum | SST (Gold) | Refrigerated | Separate serum from cells within 2 hours of collection. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.15 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Ambient | After separation from cells: 48 hours |
| Frozen | After separation from cells: 1 year |
| Refrigerated | After separation from cells: 2 weeks |
Days Performed
Sun - Sat
Turnaround Time
2 - 4 days
Methodology
| Name | Description |
|---|---|
| Semi-Quantitative Cell-Based Indirect Fluorescent Antibody |
Reference Range
| N-methyl-D-Aspartate Receptor Antibody, IgG | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| < 1:10 |
Special Info
If NMDA antibody IgG is positive, then an NMDA antibody IgG titer will be performed at an additional cost. Contaminated, hemolyzed, or severely lipemic specimens will be rejected. This test is New York DOH approved.
Clinical Info
NMDA receptor antibody is found in a subset of patients with autoimmune limbic encephalitis and may occur with or without associated tumor. Decreasing antibody levels may be associated with therapeutic response. In addition, positive results have been reported in patients with nonautoimmune phenotypes. A negative test result does not rule out a diagnosis of autoimmune limbic encephalitis. Results should be interpreted in correlation with the patients clinical history and other laboratory findings. Serum testing should be paired with CSF testing for improved diagnostic sensitivity.