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Test Code NMDAS N-methyl-D-Aspartate Receptor Antibody, IgG, Serum 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, SER (aka NMDAS)
Sunquest Order Code: NMDAS
Epic Px Code: LAB2972

Specimen Collection Type

Preferred: Gold
Acceptable: Red

Minimum Collection Volume

0.15 mL

Reference Range

< 1:10

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

Plasma. 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

80221-5

Test Alias

Anti-GluN1, Serum
Anti-NMDA, Serum
Anti-NR1, Serum
Glutamate Receptor Antibodies, Serum
N-Methyl D-Aspartate Ab, Serum
NMDA R, Serum
NMDA Receptor Ab, Serum
NMDA Reflex, Serum
NMDA Titer, Serum

Additional Information / Notes

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