Test Id : CONCS
Contactin-1 IgG Cell Binding Assay, Serum
    
        Useful For
            
                
                
                    
                    Suggests clinical disorders or settings where the test may be helpful
                
            
    
    Evaluating for chronic inflammatory demyelinating polyradiculoneuropathy and related demyelinating peripheral neuropathies
 
Determining contactin-1 IgG results as a part of a profile
    
        Method Name
            
                
                
                    
                    A short description of the method used to perform the test
                
            
    
    Only orderable as part of a profile. For more information see:
-CIDP / Chronic Inflammatory Demyelinating Polyradiculoneuropathy/Nodopathy Evaluation, Serum
-DMNES / Peripheral Nervous System Demyelinating Neuropathy, Autoimmune Evaluation, Serum
Cell Binding Assay (CBA)
    
        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
                
            
    
    Nodopathy
Paranodopathy
CIDP
CNTN1
Contactin-1
Contactin
Demyelinating neuropathy
Polyneuropathy
Polyradiculopathy
Polyradiculoneuropathy
Immune Neuropathy
Autoimmune Peripheral neuropathy
CISP
Anti-CNTN1
    
        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 a profile. For more information see:
-CIDP / Chronic Inflammatory Demyelinating Polyradiculoneuropathy/Nodopathy Evaluation, Serum
-DMNES / Peripheral Nervous System Demyelinating Neuropathy, Autoimmune Evaluation, Serum
Patient Preparation: For optimal antibody detection, specimen collection is recommended to occur prior to starting immunosuppressant medication or intravenous immunoglobulin treatment (IVIg).
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 3 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial
    
        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 for chronic inflammatory demyelinating polyradiculoneuropathy and related demyelinating peripheral neuropathies
 
Determining contactin-1 IgG results as a part of a profile
    
        Clinical Information
            
                
                
                    
                    Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
                
            
    
    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired, immune-mediated condition effecting peripheral nerves and nerve roots and is characterized by electrodiagnostic features of demyelination with a chronic onset that leads to significant disability. The prevalence of CIDP is estimated at approximately 2 to 4 cases per 100,000 persons. Although a rarer cause of polyneuropathy, it is important to recognize as it is treatable with the appropriate use of immunomodulating therapies. Although the exact immunological trigger of CIDP remains unclear, a subset of patients with suspected CIDP have been identified with autoantibodies targeting nodal-paranodal proteins. These patients share common immunopathological mechanisms of disease, clinical features, and treatment responses that are distinct from classic CIDP. A common target of these autoantibodies is the neurofascin-155 (NF155)-contactin-1 (CNTN1) complex. NF155 is expressed at the paranodal loops of Schwann cells where it interacts with CNTN1 expressed on adjacent axons. This interaction stabilizes and allows the proper organization of the paranodal axoglial junction. Antibody-mediated disruption of this interaction in animal models recapitulates the pathophysiology observed in humans.
 
Contactin-1 IgG antibodies are present in approximately 2% of patients with CIDP-like presentations. CNTN1 IgG-positive cases are more likely to present with neuropathic pain, sensory ataxia, and subacute progressive demyelinating polyradiculoneuropathy or polyradiculopathy. The majority of seropositive patients have been reported to be refractory to treatment with intravenous immune globulin (IVIg). However, some of these patients respond well to B-cell depleting therapies such as rituximab. Up to half of CNTN1 IgG-positive patients with CIDP or CIDP-like presentations have been reported to develop membranous nephropathy and, thus, screening for proteinuria may be warranted.
    
        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 a profile. For more information see:
-CIDP / Chronic Inflammatory Demyelinating Polyradiculoneuropathy/Nodopathy Evaluation, Serum
-DMNES / Peripheral Nervous System Demyelinating Neuropathy, Autoimmune Evaluation, Serum
Negative
    
        Interpretation
            
                
                
                    
                    Provides information to assist in interpretation of the test results
                
            
    
    Seropositivity for contactin-1 IgG is consistent with an immune-mediated demyelinating polyradiculoneuropathy/polyradiculopathy.
    
        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 rule out an immune-mediated demyelinating disease.
This test should only be utilized in the appropriate clinical context.
The use of immunotherapy prior to sample collection may negatively impact the sensitivity of these assays.
    
        Clinical Reference
            
                
                
                    
                    Recommendations for in-depth reading of a clinical nature
                
            
    
    1. Dubey D, Honorat JA, Shelly S, et al. Contactin-1 autoimmunity: Serologic, neurologic, and pathologic correlates. Neurol Neuroimmunol Neuroinflamm. 2020;7(4):e771
2. Cortese A, Lombardi R, Briani C, et al. Antibodies to neurofascin, contactin-1, and contactin-associated protein 1 in CIDP: Clinical relevance of IgG isotype. Neurol Neuroimmunol Neuroinflamm. 2020;7(1):e639
3. Manso C, Querol L, Mekaouche M, Illa I, Devaux JJ. Contactin-1 IgG4 antibodies cause paranode dismantling and conduction defects. Brain. 2016;139(Pt 6):1700-1712
4. Le Quintrec M, Teisseyre M, Bec N, et al. Contactin-1 is a novel target antigen in membranous nephropathy associated with chronic inflammatory demyelinating polyneuropathy. Kidney Int. 2021;100(6):1240-1249
5. Ogata H, Yamasaki R, Hiwatashi A, et al. Characterization of IgG4 anti-neurofascin 155 antibody-positive polyneuropathy. Ann Clin Transl Neurol. 2015;2(10):960-971
6. Cortese A, Lombardi R, Briani C, et al. Antibodies to neurofascin, contactin-1, and contactin-associated protein 1 in CIDP: Clinical relevance of IgG isotype. Neurol Neuroimmunol Neuroinflamm. 2020;7(1):e639
7. Querol L, Nogales-Gadea G, Rojas-Garcia R, et al. Neurofascin IgG4 antibodies in CIDP associate with disabling tremor and poor response to IVIg. Neurology. 2014;82(10):879-886
8. Shelly S, Klein CJ, Dyck PJB, et al. Neurofascin-155 immunoglobulin subtypes: Clinicopathologic associations and neurologic outcomes. Neurology. 2021;97(24):e2392-e2403
    
        Method Description
            
                
                
                    
                    Describes how the test is performed and provides a method-specific reference
                
            
    
    Patient sample is applied to a composite slide containing transfected and nontransfected EU90 cells. After incubation and washing, fluorescein-conjugated goat-antihuman IgG is applied to detect the presence of patient IgG binding.(Package insert: IIFT: Neurology Mosaics, Instructions for the indirect immunofluorescence test. EUROIMMUN; FA_112d-1_A_UK_C13, 02/25/2019)
    
        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 through Thursday, Sunday
    
        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.
                
            
    
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        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 | 
|---|---|---|
| CONCS | Contactin-1 IgG CBA, S | 101448-9 | 
| 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.
                                     | 
|---|---|---|
| 616442 | Contactin-1 IgG CBA, S | 101448-9 |