Test Id : GQ1ES
Ganglioside GQ1b Antibody, IgG, ELISA, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
Evaluating patients with an underlying demyelinating neuropathy
Supporting the diagnosis of a ganglioside GQ1b IgG-related disorder
Method Name
A short description of the method used to perform the test
Enzyme-Linked Immunosorbent Assay (ELISA)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
BBE
Bickerstaff Brainstem Encephalitis
Fisher-Bickerstaff
Fisher Syndrome
GBS
GQ1b Antibody
GQ1b-IgG
GQ1b Syndrome
Miller-Fisher Syndrome
Motor Neuropathy
Sensory Neuropathy
Specimen Type
Describes the specimen type validated for testing
Serum
Necessary Information
Provide the following information:
1. Relevant clinical information
2. Ordering provider name, phone number, mailing address, and email address
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Patient Preparation: For optimal antibody detection, specimen collection is recommended to occur prior to initiation of immunosuppressant medication or intravenous immunoglobulin treatment.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.5 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Ambient | 72 hours | ||
| Frozen | 28 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Evaluating patients with an underlying demyelinating neuropathy
Supporting the diagnosis of a ganglioside GQ1b IgG-related disorder
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Ganglioside GQ1b antibody (GQ1b IgG) is a biomarker for a group of related disorders that includes Miller Fisher syndrome (MFS), Bickerstaff brainstem encephalitis (BBE), and classic Guillain–Barre syndrome (GBS) with ophthalmoplegia. Collectively, these are referred to GQ1b IgG-related syndromes. The prevalence of GQ1b IgG in this population of patients is high and has been reported to be greater than 80% in well-defined clinical cohorts. In classic GBS, the prevalence of GQ1b IgG positivity is low but has been reported in the literature. Patients with GQ1b IgG-related disorders may not require immunotherapy, presumably because they have a good prognosis and spontaneous recovery. In severe cases, both intravenous immunoglobulin (IVIG) and plasma exchange are effective treatments for MFS and BBE. In patients with a clinical suspicion of MFS and related disorders, positivity for GQ1b IgG supports the specific clinical diagnosis and may also provide prognostic information. Although the diagnosis of these disorders is dependent on clinical evaluation and electrophysiologic studies, assessment of GQ1b IgG can further support the diagnosis.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative
Interpretation
Provides information to assist in interpretation of the test results
A positive result is consistent with an immune-mediated demyelinating neuropathy and correlation with clinical electrodiagnostic features is recommended.
Ganglioside GQ1b (GQ1b) IgG antibodies occur in Miller Fisher syndrome, Bickerstaff brainstem encephalitis, and atypical Guillain-Barre syndromes having variably present demyelinating neuropathy, ophthalmoplegia, ataxia, brainstem features with encephalitis and, less commonly, other neurogenic conditions.
A negative result does not exclude an immune-mediated demyelinating neuropathy nor a GQ1b IgG syndrome.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A negative result does not exclude the presence of disease. The use of immunotherapy prior to specimen collection may negatively impact the sensitivity of this assay.
Testing for ganglioside GQ1b antibodies should be performed near the onset of disease.
This test should be interpreted in the appropriate clinical context.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Nishimoto Y, Odaka M, Hirata K, Yuki N. Usefulness of anti-GQ1b IgG antibody testing in Fisher syndrome compared with cerebrospinal fluid examination. J Neuroimmunol. 2004;148(1-2):200-205
2. Odaka M, Yuki N, Hirata K. Anti-GQ1b IgG antibody syndrome: clinical and immunological range. J Neurol Neurosurg Psychiatry. 2001;70(1):50-55
3. Shahrizaila N, Yuki N. Bickerstaff brainstem encephalitis and Fisher syndrome: anti-GQ1b antibody syndrome. J Neurol Neurosurg Psychiatry. 2013;84(5):576-583
4. Gwathmey KG, Smith AG. Immune-Mediated Neuropathies. Neurol Clin. 2020;38(3):711-735
Method Description
Describes how the test is performed and provides a method-specific reference
Microwells are precoated with ganglioside GQ1b antigen. The calibrator, controls, and diluted patient samples are added to the wells, and autoantibodies recognizing GQ1b bind during the first incubation. After washing the wells to remove all unbound proteins, purified horseradish peroxidase-labeled anti-human IgG conjugate is added. The conjugated IgG binds to the captured human autoantibody, and the excess unbound conjugated IgG is removed by a further wash step. The bound conjugated IgG is visualized with 3,3',5,5'-tetramethylbenzidine substrate, which gives a blue reaction product, the intensity of which is proportional to a concentration of autoantibody in the sample. Acid is added to each well to stop the reaction. This produces a yellow end-product color, which is read at 450 nm. Patient results are calculated as a cutoff index (COI) by dividing the optical density (OD) of patient sera or controls by the average OD of the calibrator. Any sample with a COI greater than or equal to 1.0 is considered positive. Any sample with a COI less than 1.0 is considered negative. Results are reported qualitatively as positive or negative.(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday, Wednesday, Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
83516
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| GQ1ES | GQ1b-IgG ELISA, S | 63254-7 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 621107 | GQ1b-IgG ELISA, S | 63254-7 |