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Anti-N-methyl-D-Aspartate Receptor (NMDAR), Serum

CPT 86255

Test Details

Methodology

Immunofluorescence (IFA)

Result Turnaround Time

3 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Documents

Use

NMDAR1 is a glutamate receptor and ion channel found in neurons. This receptor is thought to be very important for controlling synaptic plasticity and mediating learning and memory functions. Antibodies against NMDAR1 generate both neurologic and psychiatric symptoms. Common symptoms include personality change, psychosis, abnormal movements, seizures and autonomic dysfunction. 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.

Limitations

Results should not be used as a diagnostic procedure without confirmation by another medically established diagnostic product or procedure.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

References

Lynch DR, Rattelle A, Dong YN, Hoslin K, Gleichman AJ, Panzer JA. Anti-NMDA Receptor Encephalitis: Clinical Features and Basic Mechanisms. Adv Pharmacol. 2018;82:235-260.29413523
Miya K, Takahashi Y, Mori H. Anti-NMDAR autoimmune encephalitis. Brain Dev. 2014 Sep;36(8):645-652.24211006
Scheer S, John RM. Anti-N-Methyl-D-Aspartate Receptor Encephalitis in children and Adolescents. J Pediatr Health Care. 2016 Jul-Aug:30(4):347-358.26507948
Venkatesan A, Adatia K. Anti-NMDA-Receptor Encephalitis: From Bench to Clinic. ASC Chem Neurosci. 2017 Dec 20;8(12):2586-2595.29077387
Zandifar A, Badrfam R. COVID-19 and anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis: Are we facing an increase in the prevalence of autoimmune encephalitis? J Med Virol. 2021 Apr;93(4):1913-1914.33336825

Custom Additional Information

Anti-NMDAR1 encephalitis represents one of the most frequent causes of autoimmune encephalitis. This type of encephalitis may also be associated with post-COVID-19 related neurological symptoms.

Specimen Requirements

Specimen

Serum

Volume

2 mL

Minimum Volume

1 mL (Note: This volume does not allow for repeat testing.)

Container

Serum from a gel-barrier tube, serum from a red-top tube, gel-barrier tube, serum transfer tube

Stability Requirements

TemperaturePeriod
Room temperature14 days
Refrigerated14 days
Frozen14 days
Freeze/thaw cyclesStable x3

Storage Instructions

Room temperature

Causes for Rejection

CSF or plasma; contaminated, hemolyzed, or severely lipemic specimens

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
505375 Anti-NMDAR, Serum 90839-2 505376 NMDAR Antibody, Cell-based IFA 90839-2
Order Code505375
Order Code NameAnti-NMDAR, Serum
Order Loinc90839-2
Result Code505376
Result Code NameNMDAR Antibody, Cell-based IFA
UofM
Result LOINC90839-2
Reflex Table for NMDAR Antibody, Cell-based IFA
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 505377 Anti-NMDAR Antibody Titer 505377 Anti-NMDAR Antibody Titer 90840-0
Reflex 1
Order Code505377
Order NameAnti-NMDAR Antibody Titer
Result Code505377
Result NameAnti-NMDAR Antibody Titer
UofM
Result LOINC90840-0