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.
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.
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
| Temperature | Period |
|---|---|
| Room temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
| Freeze/thaw cycles | Stable x3 |
Storage Instructions
Room temperature
Causes for Rejection
CSF or plasma; contaminated, hemolyzed, or severely lipemic specimens
References
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 Code | 505375 | |||||
| Order Code Name | Anti-NMDAR, Serum | |||||
| Order Loinc | 90839-2 | |||||
| Result Code | 505376 | |||||
| Result Code Name | NMDAR Antibody, Cell-based IFA | |||||
| UofM | ||||||
| Result LOINC | 90839-2 |
| 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 Code | 505377 | |||||
| Order Name | Anti-NMDAR Antibody Titer | |||||
| Result Code | 505377 | |||||
| Result Name | Anti-NMDAR Antibody Titer | |||||
| UofM | ||||||
| Result LOINC | 90840-0 | |||||