N-methyl-D-Aspartate Receptor (NMDAR) Antibody, IgG by CBA-IFA, Serum With Reflex to Titer
Ordering Recommendation
Confirm diagnosis of anti-NMDAR encephalitis. May be used in monitoring treatment response in individuals who are antibody positive.
New York DOH Approval Status
Specimen Required
Serum separator tube.
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.15 mL)
Refrigerated.
CSF or plasma. Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Methodology
Semi-Quantitative Cell-Based Indirect Fluorescent Antibody
Performed
Sun-Sat
Reported
1-3 days
Reference Interval
Less than 1:10
Interpretive Data
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.
This indirect fluorescent antibody assay utilizes full-length GluN1 transfected cell lines for the detection and semiquantification of NMDA receptor IgG antibody..
Laboratory Developed Test (LDT)
Note
If NMDA antibody IgG is positive, then an NMDA antibody IgG titer is reported. Additional charges apply.
Hotline History
Hotline History
CPT Codes
86255; if reflexed, add 86256
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
2004222 | NMDA Receptor Ab IgG CBA-IFA, Serum | 80221-5 |
Aliases
- Anti-GluN1
- Anti-NMDA
- Anti-NR1
- Glutamate Receptor Antibodies
- N-Methyl D-Aspartate Ab
- NMDA R
- NMDA Receptor Ab
- NMDA Reflex
- NMDA Titer