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


Specimen Preparation

Transfer 0.5 mL CSF to an ARUP standard transport tube. (Min: 0.15 mL)

Storage/Transport Temperature


Unacceptable Conditions

Contaminated, hemolyzed, or severely lipemic specimens.


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 1:1

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.

Compliance Category

Laboratory Developed Test (LDT)


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

Hotline History


CPT Codes

86255; if reflexed, add 86256


Component Test Code* Component Chart Name LOINC
2005165 NMDA Receptor Ab IgG CBA-IFA, CSF 80220-7
* 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 CSF
  • anti-NR1
  • Glutamate Receptor Antibodies
  • N-Methyl D-Aspartate Ab CSF
  • NMDA R
  • NMDA Receptor Ab CSF
N-methyl-D-Aspartate Receptor (NMDAR) Antibody, IgG by CBA-IFA, CSF With Reflex to Titer