N-methyl-D-Aspartate Receptor (NMDAR) Antibody, IgG by CBA-IFA, CSF 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
CSF.
Transfer 0.5 mL CSF to an ARUP standard transport tube. (Min: 0.15 mL)
Refrigerated.
Contaminated, hemolyzed, or severely lipemic specimens.
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 1:1
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.
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 CSF antibody IgG is positive, then an NMDA CSF 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 |
---|---|---|
2005165 | NMDA Receptor Ab IgG CBA-IFA, CSF | 80220-7 |
Aliases
- anti-GluN1
- Anti-NMDA CSF
- anti-NR1
- Glutamate Receptor Antibodies
- N-Methyl D-Aspartate Ab CSF
- NMDA R
- NMDA Receptor Ab CSF