N-methyl-D-Aspartate Receptor Antibody, IgG, Serum with Reflex to Titer
Ordering Recommendation

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

Semi-Quantitative Indirect Fluorescent Antibody
Tue, Fri
1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
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) 
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.

If NMDA antibody IgG is positive, then an NMDA antibody IgG titer is reported. Additional charges apply.
Hotline History
CPT Code(s)
Component Test Code*Component Chart NameLOINC
2004222N-methyl-D-Aspartate Receptor Ab, Serum80221-5
* 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