Ordering Recommendation

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

Mnemonic
NMDA IGG
Methodology

Semi-Quantitative Indirect Fluorescent Antibody

Performed

Sun-Sat

Reported

1-3 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Serum separator tube.

Specimen Preparation

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)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

CSF or plasma. Contaminated, hemolyzed, or severely lipemic specimens.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval

< 1:10

Interpretive Data

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.

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Note

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

Hotline History
N/A
CPT Codes

86255; if reflexed, add 86256

Components
Component Test Code* Component Chart Name LOINC
2004222 N-methyl-D-Aspartate Receptor Ab, Serum 80221-5
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Anti-GluN1
  • Anti-NMDA
  • Anti-NR1
  • Glutamate Receptor Antibodies
  • N-Methyl D-Aspartate Ab
  • NMDA R
  • NMDA Receptor Ab
  • NMDA Reflex
  • NMDA Titer
N-methyl-D-Aspartate Receptor Antibody, IgG, Serum with Reflex to Titer