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

This test is New York state approved.

Specimen Required

Patient Preparation

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


Unacceptable Conditions

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)


Semi-Quantitative Cell-Based Indirect Fluorescent Antibody




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..

Compliance Category

Laboratory Developed Test (LDT)


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

Hotline History


CPT Codes

86255; if reflexed, add 86256


Component Test Code* Component Chart Name LOINC
2004222 NMDA Receptor Ab IgG CBA-IFA, 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.


  • 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 (NMDAR) Antibody, IgG by CBA-IFA, Serum With Reflex to Titer