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Test Code GL5IS Metabotropic Glutamate Receptor-5 (mGluR5) IgG, Tissue Immunofluorescence, Serum (Non-Orderable)


Specimen Required


Only orderable as part of a profile. For more information see:

-DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

-ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

-EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

-MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

-PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum


Secondary ID

623395

Useful For

Only orderable as part of a profile. For more information see:

DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum

 

Evaluating patients suspected of having autoimmune encephalitis using serum specimens

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
GL5CS mGluR5 Ab CBA, S No No
GL5TS mGluR5 Ab IFA Titer, S No No

Testing Algorithm

If the indirect immunofluorescence (IFA) pattern suggests mGluR5 (metabotropic glutamate receptor-5), then the mGluR5 antibody cell-binding assay and mGluR5 antibody IFA titer will be performed at an additional charge.

Method Name

Only orderable as part of a profile. For more information see:

-DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

-ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

-EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

-MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

-PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum

 

Indirect Immunofluorescence Assay (IFA)

Reporting Name

mGluR5 Ab IFA, S

Specimen Type

Serum

Specimen Minimum Volume

Serum: 1 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Clinical Information

Metabotropic glutamate receptor-5 (mGluR5-IgG) is a marker of autoimmune encephalitis. Patients who are mGluR5-IgG positive present with neuropsychiatric syndrome, cognitive decline, movement disorders, sleep dysfunction and seizures, which can occur with or without tumor.

Reference Values

Only orderable as part of a profile. For more information see:

-DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

-ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

-EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

-MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

-PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum

 

Negative

Interpretation

A positive result is consistent with metabotropic glutamate receptor-5 (mGluR5) autoimmunity that manifests as autoimmune encephalitis.

Method Description

The patient's sample is tested by a standardized immunofluorescence assay that uses a composite frozen section of mouse cerebellum, kidney, and gut tissues. After incubation with the sample and washing, fluorescein-conjugated goat-antihuman IgG is applied. Neuron-specific autoantibodies are identified by their characteristic fluorescence staining patterns. Samples that score positive for any neuronal nuclear or cytoplasmic autoantibody are titrated. Interference by coexisting non-neuron-specific autoantibodies can usually be eliminated by serologic absorption.(Honorat JA, Komorowski L, Josephs KA, et al. IgLON5 antibody: Neurological accompaniments and outcomes in 20 patients. Neurol Neuroimmunol Neuroinflamm. 2017;4(5):e385. Published 2017 Jul 18. doi:10.1212/NXI.0000000000000385)

Day(s) Performed

Varies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

86255

LOINC Code Information

Test ID Test Order Name Order LOINC Value
GL5IS mGluR5 Ab IFA, S In Process

 

Result ID Test Result Name Result LOINC Value
623395 mGluR5 Ab IFA, S In Process