Test Id : AAGFS
Alpha-3 Beta-4 Ganglionic Neuronal Acetylcholine Receptor Binding Antibody, Flow Cytometry, Serum (Non-Orderable)
Useful For
Suggests clinical disorders or settings where the test may be helpful
Only orderable as a reflex. For more information see:
DYS2 / Dysautonomia, Autoimmune/Paraneoplastic Evaluation, Serum
GID2 / Gastrointestinal Dysmotility, Autoimmune/Paraneoplastic Evaluation, Serum
Evaluating patients with suspected autoimmune autonomic ganglionopathy and autoimmune gastrointestinal dysmotility using serum specimens
Reporting alpha-3 beta-4 ganglionic neuronal acetylcholine receptor binding antibody results as part of a profile
Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.
| Test Id | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| AAGTS | AChR Alpha3 Gang Flow Titer, S | No | No |
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When the results of this assay require further evaluation, the reflex titer test will be performed at an additional charge.
Method Name
A short description of the method used to perform the test
Only orderable as part of profile. For more information see:
-DYS2 / Dysautonomia, Autoimmune/Paraneoplastic Evaluation, Serum
-GID2 / Gastrointestinal Dysmotility, Autoimmune/Paraneoplastic Evaluation, Serum
Flow Cytometry
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
Alpha-3 beta-4 gnAChR - alpha-3 Beta-4 Ganglionic Neuronal Acetylcholine Receptor
Alpha-3 Beta-4 abs - Ganglionic Acetylcholine Receptor (Alpha3, Beta4) Autoantibody
Alpha-3 beta-4 antibodies - Ganglionic Acetylcholine Receptor (Alpha3, Beta4) Autoantibody
Neurona alpha-3 - gnAChR binding antibodies
Alpha-3 abs - Nicotinic AChR Ab
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When the results of this assay require further evaluation, the reflex titer test will be performed at an additional charge.
Specimen Type
Describes the specimen type validated for testing
Serum
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Only orderable as part of profile. For more information see:
-DYS2 / Dysautonomia, Autoimmune/Paraneoplastic Evaluation, Serum
-GID2 / Gastrointestinal Dysmotility, Autoimmune/Paraneoplastic Evaluation, Serum
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.
Serum: 1 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
Only orderable as a reflex. For more information see:
DYS2 / Dysautonomia, Autoimmune/Paraneoplastic Evaluation, Serum
GID2 / Gastrointestinal Dysmotility, Autoimmune/Paraneoplastic Evaluation, Serum
Evaluating patients with suspected autoimmune autonomic ganglionopathy and autoimmune gastrointestinal dysmotility using serum specimens
Reporting alpha-3 beta-4 ganglionic neuronal acetylcholine receptor binding antibody results as part of a profile
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When the results of this assay require further evaluation, the reflex titer test will be performed at an additional charge.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The assay for ganglionic acetylcholine receptor binding antibodies (alpha-3 beta-4) is most useful as a screening test for autoimmune autonomic ganglionopathy (AAG), a form of autoimmune dysautonomia which can manifest as pandysautonomia (several of fixed pupillary dilatation, orthostatic hypotension, sweat loss, gastroparesis, small bowel pseudo-obstruction, constipation and urinary retention due to bladder hypocontractility) or limited forms such as autoimmune gastrointestinal dysmotility. Occasionally, AAG may occur in a paraneoplastic context accompanying diverse carcinomas or thymoma. AAG is generally an immune therapy responsive disease.
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.
Only orderable as part of profile. For more information see:
-DYS2 / Dysautonomia, Autoimmune/Paraneoplastic Evaluation, Serum
-GID2 / Gastrointestinal Dysmotility, Autoimmune/Paraneoplastic Evaluation, Serum
Negative
Interpretation
Provides information to assist in interpretation of the test results
Seropositivity for ganglionic acetylcholine receptor binding autoantibodies supports the clinical diagnosis of autoimmune autonomic failure with neurological presentations including orthostatic hypotension, constipation, dilated pupils, dry eyes and dry mouth, fainting, urinary retention. Immune therapies such as corticosteroids, plasma exchange and intravenous immunoglobulin may lead to disease remission.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Negative results do not exclude the diagnosis of autoimmune autonomic failure.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Vernino S, Auger RG, Emslie-Smith AM, Harper CM, Lennon VA. Myasthenia, thymoma, presynaptic antibodies, and a continuum of neuromuscular hyperexcitability. Neurology. 1999;53(6):1233-1239
2. McKeon A, Lennon VA, Lachance DH, Fealey RD, Pittock SJ. Ganglionic acetylcholine receptor autoantibody: oncological, neurological, and serological accompaniments. Arch Neurol. 2009;66(6):735-741. doi:10.1001/archneurol.2009.78
3. Cutsforth-Gregory JK, McKeon A, Coon EA, et al. Ganglionic antibody level as a predictor of severity of autonomic failure. Mayo Clin Proc. 2018;93(10):1440-1447
4. Karagiorgou K, Dandoulaki M, Mantegazza R, et al. Novel Cell-Based Assay for Alpha-3 Nicotinic Receptor Antibodies Detects Antibodies Exclusively in Autoimmune Autonomic Ganglionopathy. J Neurol Neuroimmunol Neuroinflamm. 2022;9(3):e1162
Method Description
Describes how the test is performed and provides a method-specific reference
This assay is a live cell–based binding assay using flow cytometry to detect ganglionic acetylcholine receptor (AChR) binding antibodies in patient serum. Human embryonic kidney cells (HEK293) transiently expressing human alpha-3 beta-4 ganglionic AChR subunits, along with accessory proteins required for receptor expression, are used as the antigen source. Receptor expression is enhanced prior to analysis under controlled culture conditions. Cells are incubated with diluted patient serum to allow binding of AChR-specific antibodies to surface-expressed receptors. Bound human IgG is detected using a fluorophore-conjugated anti-human IgG secondary antibody, with a viability dye included to exclude non-viable cells. Fluorescence intensity is measured by flow cytometry, and antibody binding is assessed by comparing signal from AChR-expressing cells to control cells lacking receptor expression. A humanized AChR-specific monoclonal antibody is used as an assay calibrator. The IgG binding index (IBI) of patient samples is compared to the assay calibrator to calculate a cut-off Index (COI). Patient samples with a COI greater than or equal to 1.0 are reported as positive. Positive samples are further titrated to determine the end-point dilution, defined as the highest serum dilution that remains above the calibrator.(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.
Varies
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.
86255
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 |
|---|---|---|
| AAGFS | AChR Alpha3 Ganglionic Flow, S | In Process |
| 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.
|
|---|---|---|
| 622854 | AChR Alpha3 Ganglionic Flow, S | In Process |