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Test Code NMDAC N-methyl-D-Aspartate Receptor Antibody, IgG, CSF with Reflex to Titer

Clinical Indications

Confirm diagnosis of anti-NMDAR encephalitis. May be used in monitoring treatment response in individuals who are antibody positive.

Additional Test Codes

Epic Order Name: NMDA RECEPTOR AB, CSF (aka NMDAC)
Sunquest Order Code: NMDAC
Epic Px Code: LAB2973

Specimen Collection Type

CSF

Minimum Collection Volume

0.15 mL

Reference Range

< 1:1

Critical Value

N/A

Interpretation

Anti-NMDA receptor IgG 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; therefore, clinical correlation must be strongly considered. A negative test result does not rule out a diagnosis of autoimmune limbic encephalitis.

Rejection Criteria

Contaminated, hemolyzed, or severely lipemic specimens.

Specimen Availability for Add-on Testing

2 Days

Specimen Stability

Refrigerated (preferred): 2 weeks
Ambient: 48 hours
Frozen: 1 year

Day(s) Performed

Tue, Fri

Performing Lab- Department

TUKHS-BH-Mail Outs

CPT Code

86255; if reflexed, add 86256

LOINC Code

80220-7

Test Alias

anti-GluN1
Anti-NMDA CSF
anti-NR1
Glutamate Receptor Antibodies
N-Methyl D-Aspartate Ab CSF
NMDA R CSF
NMDA Receptor Ab CSF

Additional Information / Notes

If NMDA CSF antibody IgG is positive, then an NMDA CSF antibody IgG titer is reported.