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HelpTest ID DMS2 Dementia, Autoimmune/Paraneoplastic Evaluation, Serum
Ordering Guidance
Multiple neurological phenotype-specific autoimmune/paraneoplastic evaluations are available. For more information as well as phenotype-specific testing options, refer to Autoimmune Neurology Test Ordering Guide.
When more than one evaluation is ordered on the same order number, the duplicate test will be canceled.
For a list of antibodies performed with each evaluation, see Autoimmune Neurology Antibody Matrix.
This test should not be requested for patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. The specific waiting period before specimen collection will depend on the isotope administered, the dose given, and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held 1 week and assayed if sufficiently decayed or canceled if radioactivity remains.
Necessary Information
Provide the following information:
-Relevant clinical information
-Ordering provider name, phone number, mailing address, and e-mail address
Specimen Required
Patient Preparation:
1. For optimal antibody detection, specimen collection is recommended before initiation of immunosuppressant medication or intravenous immunoglobulin treatment.
2. For 24 hours before specimen collection, patient should not receive general anesthetic or take muscle-relaxant drugs.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 4 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Forms
If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.
Useful For
Investigating new onset dementia and cognitive impairment plus 1 or more of the following using serum specimens:
-Rapid onset and progression
-Fluctuating course
-Psychiatric accompaniments (psychosis, hallucinations)
-Movement disorder (myoclonus, tremor, dyskinesias)
-Headache
-Autoimmune stigmata (personal history or family history or signs of diabetes mellitus, thyroid disorder, vitiligo, poliosis [premature graying], myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus)
-Smoking history (over 20 pack-years) or other cancer risk factors
-History of cancer
-Inflammatory cerebrospinal fluid
-Neuroimaging findings atypical for degenerative etiology
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| ADMSI | Dementia, Interpretation, S | No | Yes |
| AMPCS | AMPA-R Ab CBA, S | No | Yes |
| AMPHS | Amphiphysin Ab, S | No | Yes |
| AGN1S | Anti-Glial Nuclear Ab, Type 1 | No | Yes |
| ANN1S | Anti-Neuronal Nuclear Ab, Type 1 | No | Yes |
| ANN2S | Anti-Neuronal Nuclear Ab, Type 2 | No | Yes |
| ANN3S | Anti-Neuronal Nuclear Ab, Type 3 | No | Yes |
| CS2CS | CASPR2-IgG CBA, S | No | Yes |
| CRMS | CRMP-5-IgG, S | No | Yes |
| DPPCS | DPPX Ab CBA, S | No | Yes |
| GABCS | GABA-B-R Ab CBA, S | No | Yes |
| GD65S | GAD65 Ab Assay, S | Yes | Yes |
| GFAIS | GFAP IFA, S | No | Yes |
| IG5CS | IgLON5 CBA, S | No | Yes |
| LG1CS | LGI1-IgG CBA, S | No | Yes |
| GL1IS | mGluR1 Ab IFA, S | No | Yes |
| NCDIS | Neurochondrin IFA, S | No | Yes |
| NIFIS | NIF IFA, S | No | Yes |
| NMDCS | NMDA-R Ab CBA, S | No | Yes |
| PCAB2 | Purkinje Cell Cytoplasmic Ab Type 2 | No | Yes |
| PCATR | Purkinje Cell Cytoplasmic Ab Type Tr | No | Yes |
| PDEIS | PDE10A Ab IFA, S | No | Yes |
| T46IS | TRIM46 Ab IFA, S | No | Yes |
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| AGNBS | AGNA-1 Immunoblot, S | No | No |
| AINCS | Alpha Internexin CBA, S | No | No |
| AMPIS | AMPA-R Ab IF Titer Assay, S | No | No |
| AMIBS | Amphiphysin Immunoblot, S | No | No |
| AN1BS | ANNA-1 Immunoblot, S | No | No |
| AN2BS | ANNA-2 Immunoblot, S | No | No |
| CRMWS | CRMP-5-IgG Western Blot, S | Yes | No |
| DPPTS | DPPX Ab IFA Titer, S | No | No |
| GABIS | GABA-B-R Ab IF Titer Assay, S | No | No |
| GFACS | GFAP CBA, S | No | No |
| GFATS | GFAP IFA Titer, S | No | No |
| IG5TS | IgLON5 IFA Titer, S | No | No |
| GL1CS | mGluR1 Ab CBA, S | No | No |
| GL1TS | mGluR1 Ab IFA Titer, S | No | No |
| NFHCS | NIF Heavy Chain CBA, S | No | No |
| NIFTS | NIF IFA Titer, S | No | No |
| NFLCS | NIF Light Chain CBA, S | No | No |
| NMDIS | NMDA-R Ab IF Titer Assay, S | No | No |
| PCTBS | PCA-Tr Immunoblot, S | No | No |
| AN1TS | ANNA-1 Titer, S | No | No |
| AN2TS | ANNA-2 Titer, S | No | No |
| AN3TS | ANNA-3 Titer, S | No | No |
| APHTS | Amphiphysin Ab Titer, S | No | No |
| CRMTS | CRMP-5-IgG Titer, S | No | No |
| NCDCS | Neurochondrin CBA, S | No | No |
| NCDTS | Neurochondrin IFA Titer, S | No | No |
| PC2TS | PCA-2 Titer, S | No | No |
| PCTTS | PCA-Tr Titer, S | No | No |
| AGNTS | AGNA-1 Titer, S | No | No |
| PDETS | PDE10A Ab IFA Titer, S | No | No |
| T46CS | TRIM46 Ab CBA, S | No | No |
| T46TS | TRIM46 Ab IFA Titer, S | No | No |
Testing Algorithm
If the indirect immunofluorescence assay (IFA) pattern suggests antiglial nuclear antibody (AGNA)-1, then the AGNA-1 immunoblot and AGNA-1 IFA titer will be performed at an additional charge.
If the IFA pattern suggests antineuronal nuclear antibody type 1 (ANNA-1), then the ANNA-1 immunoblot, ANNA-1 IFA titer, and ANNA-2 immunoblot will be performed at an additional charge.
If the IFA pattern suggests ANNA-2 antibody, then the ANNA-2 immunoblot, ANNA-2 IFA titer, and ANNA-1 immunoblot will be performed at an additional charge.
If client requests or if the IFA pattern suggests ANNA-3 antibody, then the ANNA-3 IFA titer will be performed at an additional charge.
If the IFA pattern suggests amphiphysin antibody, then the amphiphysin immunoblot and amphiphysin IFA titer will be performed at an additional charge.
If client requests or if the IFA patterns suggest collapsin response-mediator protein 5 (CRMP-5)-IgG, then the CRMP-5-IgG Western blot and CRMP-5-IgG IFA titer will be performed at an additional charge.
If the AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid 9) receptor antibody cell-binding assay (CBA) result is positive, then the AMPA receptor antibody IFA titer will be performed at an additional charge.
If the contactin-associated protein-like-2 (CASPR2)-receptor antibody CBA result is positive, then the CRMP-5-IgG Western blot will be performed at an additional charge.
If the gamma-aminobutyric acid B (GABA-B) receptor antibody CBA result is positive, then the GABA-B receptor antibody IF titer will be performed at an additional charge.
If IFA pattern suggests glial fibrillary acidic protein (GFAP) antibody, then the GFAP IFA titer and GFAP CBA will be performed at an additional charge.
If the N-methyl-D-aspartate (NMDA)-receptor antibody CBA is positive, then NMDA receptor antibody IF titer will be performed at an additional charge.
If the IFA pattern suggests PCA-Tr antibody, then the PCA-Tr immunoblot and PCA-Tr IFA titer will be performed at an additional charge.
If dipeptidyl-peptidase-like protein-6 (DPPX) antibody CBA result is positive, then the DPPX IFA titer will be performed at an additional charge.
If the IFA pattern suggests metabotropic glutamate receptor 1 (mGluR1) antibody, then the mGluR1 antibody CBA and mGluR1 IFA titer will be performed at an additional charge.
If the IgLON5 antibody CBA result is positive, then the IgLON5 IFA titer will be performed at an additional charge.
If the IFA pattern suggests neuronal intermediate filament (NIF) antibody, then the alpha internexin CBA, NIF heavy chain CBA, NIF light chain CBA, and NIF IFA titer will be performed at an additional charge.
If the IFA pattern suggests neurochondrin antibody, then the neurochondrin antibody CBA and neurochondrin IFA titer will be performed at an additional charge.
If the IFA pattern suggests tripartite motif-containing protein 46 (TRIM46) antibody, then the TRIM46 antibody CBA and TRIM46 IFA titer will be performed at an additional charge.
If the IFA pattern suggests phosphodiesterase 10A (PDE10A) antibody, then the PDE10A antibody IFA titer will be performed at an additional charge.
For more information see Autoimmune/Paraneoplastic Dementia Evaluation Algorithm-Serum.
Method Name
AMPCS, CS2CS, LG1CS, DPPCS, GABCS, GFACS, IG5CS, GL1CS, NCDCS, AINCS, NFLCS, NFHCS, NMDCS, T46CS: Cell Binding Assay (CBA)
AGN1S, AGNTS, AMPIS, AMPHS, APHTS, ANN1S, AN1TS, ANN2S, AN2TS, ANN3S, AN3TS, CRMS, CRMTS, DPPTS, GABIS, GFAIS, GFATS, IG5TS, GL1IS, GL1TS, NCDIS, NCDTS, NIFIS, NIFTS, NMDIS, PCAB2, PC2TS, PCATR, PCTTS, PDEIS, PDETS, T46IS, T46TS: Indirect Immunofluorescence Assay (IFA)
GD65S: Radioimmunoassay (RIA)
CRMWS: Western Blot (WB)
AGNBS, AMIBS, AN1BS, AN2BS, PCTBS: Immunoblot (IB)
Reporting Name
Dementia, Autoimm/Paraneo, SSpecimen Type
SerumSpecimen Minimum Volume
2.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| 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
The rapid identification of subacute cognitive decline as autoimmune dementia facilitates optimum treatment with immunotherapy and an expedited search for a limited stage of cancer in some patients. Traditionally, neurologists have been reluctant to consider a diagnosis of an autoimmune cognitive disorder in the absence of delirium. However, some recent case series and clinical-serologic observations have suggested a growing appreciation for autoimmune neurologic disorders presenting with features of a rapidly progressive dementia rather than delirium. These disorders can affect all age groups.
Unfortunately, these potentially reversible conditions may be misdiagnosed as being progressive neurodegenerative (currently irreversible) disorders with devastating consequences for the patient. In the evaluation of a patient with cognitive decline, clinicians should consider the possibility of an autoimmune etiology on their list of differential diagnoses. The importance of not overlooking this possibility rests in the experience that these patients have a potentially immunotherapy-responsive, reversible disorder. The development and widespread availability of neural antibody marker testing has changed this perspective so that other presenting symptoms, such as personality change, executive dysfunction, and psychiatric symptoms, are increasingly recognized in an autoimmune context.
Clues that are helpful in identifying patients with an autoimmune dementia can be summarized as a triad of:
-Suspicious clinical features (a subacute onset of symptoms, a rapidly progressive course, and fluctuating symptoms) and radiological findings
-Detection of cerebrospinal fluid (CSF) or serological biomarkers of autoimmunity
-Response to immunotherapy
Detection of neural autoantibodies in serum or CSF serves 2 purposes; to inform the physician of a likely autoimmune etiology and to raise suspicion for a paraneoplastic cause. The neurological associations of neural autoantibodies tend to be diverse and multifocal, although certain syndromic associations may apply. For example, LGI1 (leucine-rich, glioma inactivated 1) antibody was initially considered to be specific for autoimmune limbic encephalitis, but, over time, other presentations have been reported, including rapidly progressive course of cognitive decline mimicking neurodegenerative dementia.
Since neurological presentations are often multifocal and diverse, comprehensive antibody testing is usually more informative than testing for 1 or 2 selected antibodies. Some of the antibodies are highly predictive of an unsuspected underlying cancer. For example, small-cell lung carcinoma (antineuronal nuclear antibody-type 1 [ANNA-1]; collapsin response-mediator protein-5 neuronal [CRMP-5-IgG]), ovarian teratoma (N-methyl-D-aspartate receptor: NMDA-R), and thymoma (CRMP-5 IgG).
Also, a profile of seropositivity for multiple autoantibodies may be informative for cancer type. For example, in a patient presenting with a rapidly progressive dementia who has CRMP-5-IgG, and subsequent testing reveals muscle acetylcholine receptor (AChR) binding antibody, the findings should raise a high suspicion for thymoma. If an associated tumor is found, its resection or ablation optimizes the neurological outcome.
Antibody testing on CSF is additionally helpful, particularly when serum testing is negative, although, in some circumstances, testing both serum and CSF simultaneously is pertinent. Testing of CSF is recommended for some antibodies (eg, NMDA-R antibody and glial fibrillary acidic protein [GFAP]-IgG) because CSF testing is more sensitive and specific.
Reference Values
|
Test ID |
Reporting name |
Methodology |
Reference value |
|
ADMSI |
Dementia, Interpretation, S |
Medical interpretation |
Interpretive report |
|
AMPCS |
AMPA-R Ab CBA, S |
CBA |
Negative |
|
AMPHS |
Amphiphysin Ab, S |
IFA |
<1:240 |
|
AGN1S |
Anti-Glial Nuclear Ab, Type 1 |
IFA |
<1:240 |
|
ANN1S |
Anti-Neuronal Nuclear Ab, Type 1 |
IFA |
<1:240 |
|
ANN2S |
Anti-Neuronal Nuclear Ab, Type 2 |
IFA |
<1:240 |
|
ANN3S |
Anti-Neuronal Nuclear Ab, Type 3 |
IFA |
<1:240 |
|
CS2CS |
CASPR2-IgG CBA, S |
CBA |
Negative |
|
CRMS |
CRMP-5-IgG, S |
IFA |
<1:240 |
|
DPPCS |
DPPX Ab CBA, S |
CBA |
Negative |
|
GABCS |
GABA-B-R Ab CBA, S |
CBA |
Negative |
|
GD65S |
GAD65 Ab Assay, S |
RIA |
≤0.02 nmol/L Reference values apply to all ages. |
|
GFAIS |
GFAP IFA, S |
IFA |
Negative |
|
IG5CS |
IgLON5 CBA, S |
CBA |
Negative |
|
LG1CS |
LGI1-IgG CBA, S |
CBA |
Negative |
|
GL1IS |
mGluR1 Ab IFA, S |
IFA |
Negative |
|
NCDIS |
Neurochondrin IFA, S |
IFA |
Negative |
|
NIFIS |
NIF IFA, S |
IFA |
Negative |
|
NMDCS |
NMDA-R Ab CBA, S |
CBA |
Negative |
|
PCAB2 |
Purkinje Cell Cytoplasmic Ab Type 2 |
IFA |
<1:240 |
|
PCATR |
Purkinje Cell Cytoplasmic Ab Type Tr |
IFA |
<1:240 |
|
PDEIS |
PDE10A Ab IFA, S |
IFA |
Negative |
|
T46IS |
TRIM46 IFA, S |
IFA |
Negative |
Reflex Information:
|
Test ID |
Reporting name |
Methodology |
Reference value |
|
AGNBS |
AGNA-1 Immunoblot, S |
IB |
Negative |
|
AGNTS |
AGNA-1 Titer, S |
IFA |
<1:240 |
|
AINCS |
Alpha Internexin CBA, S |
CBA |
Negative |
|
AMPIS |
AMPA-R Ab IF Titer Assay, S |
IFA |
<1:240 |
|
AMIBS |
Amphiphysin Immunoblot, S |
IB |
Negative |
|
AN1BS |
ANNA-1 Immunoblot, S |
IB |
Negative |
|
AN1TS |
ANNA-1 Titer, S |
IFA |
<1:240 |
|
AN2BS |
ANNA-2 Immunoblot, S |
IB |
Negative |
|
AN2TS |
ANNA-2 Titer, S |
IFA |
<1:240 |
|
AN3TS |
ANNA-3 Titer, S |
IFA |
<1:240 |
|
APHTS |
Amphiphysin Ab Titer, S |
IFA |
<1:240 |
|
CRMTS |
CRMP-5-IgG Titer, S |
IFA |
<1:240 |
|
CRMWS |
CRMP-5-IgG Western Blot, S |
WB |
Negative |
|
DPPTS |
DPPX Ab IFA Titer, S |
IFA |
<1:240 |
|
GABIS |
GABA-B-R Ab IF Titer Assay, S |
IFA |
<1:240 |
|
GFACS |
GFAP CBA, S |
CBA |
Negative |
|
GFATS |
GFAP IFA Titer, S |
IFA |
<1:240 |
|
IG5TS |
IgLON5 IFA Titer, S |
IFA |
<1:240 |
|
GL1CS |
mGluR1 Ab CBA, S |
CBA |
Negative |
|
GL1TS |
mGluR1 Ab IFA Titer, S |
IFA |
<1:240 |
|
NCDCS |
Neurochondrin CBA, S |
CBA |
Negative |
|
NCDTS |
Neurochondrin IFA Titer, S |
IFA |
<1:240 |
|
NFHCS |
NIF Heavy Chain CBA, S |
CBA |
Negative |
|
NIFTS |
NIF IFA Titer, S |
IFA |
<1:240 |
|
NFLCS |
NIF Light Chain CBA, S |
CBA |
Negative |
|
NMDIS |
NMDA-R Ab IF Titer Assay, S |
IFA |
<1:240 |
|
PC2TS |
PCA-2 Titer, S |
IFA |
<1:240 |
|
PCTTS |
PCA-Tr Titer, S |
IFA |
<1:240 |
|
PCTBS |
PCA-Tr Immunoblot, S |
IB |
Negative |
|
PDETS |
PDE10A Ab IFA Titer, S |
IFA |
<1:240 |
|
T46CS |
TRIM46 CBA, S |
CBA |
Negative |
|
T46TS |
TRIM46 IFA Titer, S |
IFA |
<1:240 |
*Methodology abbreviations used:
Immunofluorescence assay (IFA)
Cell-binding assay (CBA)
Western blot (WB)
Radioimmunoassay (RIA)
Immunoblot (IB)
Neuron-restricted patterns of IgG staining that do not fulfill criteria for ANNA-1, ANNA-2, ANNA-3 CRMP-5-IgG, PCA-1, PCA-2, or PCA-Tr may be reported as "unclassified anti-neuronal IgG." Complex patterns that include nonneuronal elements may be reported as "uninterpretable."
Note: CRMP-5 titers lower than 1:240 are detectable by recombinant CRMP-5 Western blot analysis. CRMP-5 Western blot analysis will be done on request on stored serum (held 4 weeks). This supplemental testing is recommended in cases of chorea, vision loss, cranial neuropathy, and myelopathy. Call the Neuroimmunology Laboratory at 800-533-1710 to request CRMP-5 Western blot.
Interpretation
Antibodies specific for neuronal, glial, or muscle proteins are valuable serological markers of autoimmune epilepsy and of a patient's immune response to cancer. These autoantibodies are not found in healthy subjects and are usually accompanied by subacute neurological symptoms and signs. It is not uncommon for more than 1 of the following autoantibodies to be detected in patients with autoimmune dementia:
-Plasma membrane antibodies (N-methyl-D-aspartate [NMDA] receptor; 2-amino-3-[5-methyl-3-oxo-1,2-oxazol-4-yl] propanoic acid [AMPA] receptor; gamma-amino butyric acid [GABA-B] receptor). These autoantibodies are all potential effectors of dysfunction.
-Neuronal nuclear autoantibody, type 1 (ANNA-1) or type 3 (ANNA-3).
-Neuronal or muscle cytoplasmic antibodies (amphiphysin, Purkinje cell antibody-type 2 [PCA-2], collapsin response-mediator protein-5 neuronal [CRMP-5-IgG], or glutamic acid decarboxylase [GAD65] antibody).
Cautions
Negative results do not exclude autoimmune dementia or cancer.
This test does not detect Ma1 or Ma2 antibodies (also known as MaTa). Ma2 antibody has been described in patients with brainstem and limbic encephalitis in the context of testicular germ cell neoplasms. Scrotal ultrasound is advisable in men who present with unexplained subacute encephalitis.
Intravenous immunoglobulin (IVIg) treatment prior to the serum collection may cause a false-positive result.
Clinical Reference
1. Sechi E, Flanagan EP. Diagnosis and management of autoimmune dementia. Curr Treat Options Neurol. 2019;21(3):11. Published 2019 Feb 27. doi:10.1007/s11940-019-0550-9
2. Bastiaansen AEM, van Steenhoven RW, de Bruijn MAAM, et al. Autoimmune encephalitis resembling dementia syndromes. Neurol Neuroimmunol Neuroinflamm. 2021;8(5):e1039. Published 2021 Aug 2. doi:10.1212/NXI.0000000000001039
3. Flanagan EP, Geschwind MD, Lopez-Chiriboga AS, et al. Autoimmune encephalitis misdiagnosis in adults. JAMA Neurol. 2023;80(1):30-39. doi:10.1001/jamaneurol.2022.4251
4. Orozco E, Valencia-Sanchez C, Britton J, et al. Autoimmune encephalitis criteria in clinical practice. Neurol Clin Pract. 2023;13(3):e200151. doi:10.1212/CPJ.0000000000200151
5. Bastiaansen AEM, van Steenhoven RW, Te Vaarwerk ES, et al. Antibodies associated with autoimmune encephalitis in patients with presumed neurodegenerative dementia. Neurol Neuroimmunol Neuroinflamm. 2023;10(5):e200137. Published 2023 Jun 13. doi:10.1212/NXI.0000000000200137
Method Description
Indirect Immunofluorescence Assay:
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 sample and washing, fluorescein-conjugated goat-antihuman IgG is applied. Neuron-specific autoantibodies are identified by their characteristic fluorescence staining patterns. Samples that are scored positive for any neuronal nuclear or cytoplasmic autoantibody are titrated to an endpoint. 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. doi:10.1212/NXI.0000000000000385)
Radioimmunoassay:
(125)I-labeled recombinant human antigens or labeled receptors are incubated with patient specimen. After incubation, anti-human IgG is added to form an immunoprecipitate. The amount of (125)I-labeled antigen in the immunoprecipitate is measured using a gamma-counter. The amount of gamma emission in the precipitate is proportional to the amount of antigen-specific IgG in the specimen. Results are reported as units of precipitated antigen (nmol) per liter of patient sample.(Griesmann GE, Kryzer TJ, Lennon VA: Autoantibody profiles of myasthenia gravis and Lambert-Eaton myasthenic syndrome. In: Rose NR, Hamilton RG, eds. Manual of Clinical and Laboratory Immunology. 6th ed. ASM Press; 2002:1005-1012; Walikonis JE, Lennon VA. Radioimmunoassay for glutamic acid decarboxylase [GAD65] autoantibodies as a diagnostic aid for stiff-man syndrome and a correlate of susceptibility to type 1 diabetes mellitus. Mayo Clin Proc. 1998;73[12]:1161-1166; Jones AL, Flanagan EP, Pittock SJ, et al. Responses to and outcomes of treatment of autoimmune cerebellar ataxia in adults. JAMA Neurol. 2015;72[11]:1304-1312. doi:10.1001/jamaneurol.2015.2378)
Western Blot:
Neuronal antigens extracted aqueously from adult rat cerebellum, full-length recombinant human collapsin response-mediator protein-5 (CRMP-5), or full-length recombinant human amphiphysin protein is denatured, reduced, and separated by electrophoresis on 10% polyacrylamide gel. IgG is detected autoradiographically by enhanced chemiluminescence.(Yu Z, Kryzer TJ, Griesmann GE, et al. CRMP-5 neuronal autoantibody: marker of lung cancer and thymoma-related autoimmunity. Ann Neurol. 2001;49[2]:146-154; Dubey D, Jitprapaikulsan J, Bi H, et al. Amphiphysin-IgG autoimmune neuropathy: A recognizable clinicopathologic syndrome. Neurology. 2019;93[20]:e1873-e1880. doi:10.1212/WNL.0000000000008472)
Immunoblot:
All steps are performed at room temperature (18-28° C) utilizing the EUROBlot One instrument. Diluted patient serum (1:101) is added to test strips (strips containing recombinant antigen manufactured and purified using biochemical methods) in individual channels and incubated for 30 minutes. Positive serums will bind to the purified recombinant antigen and negative serums will not bind. Strips are washed to remove unbound serum antibodies and then incubated with anti-human IgG antibodies (alkaline phosphatase-labelled) and incubated for 30 minutes. The strips are again washed to remove unbound anti-human IgG antibodies and nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indolylphosphate (NBT/BCIP) substrate is added. Alkaline phosphatase enzyme converts the soluble substrate into a colored insoluble product on the membrane to produces a black band. Strips are digitized via picture capture on the EUROBlot One instrument and evaluated with the EUROLineScan software.(O'Connor K, Waters P, Komorowski L, et al. GABAA receptor autoimmunity: A multicenter experience. Neurol Neuroimmunol Neuroinflamm. 2019;6[3]:e552. doi:10.1212/NXI.0000000000000552)
Cell-Binding Assay:
Patient specimen is applied to a composite slide containing transfected and nontransfected HEK-293 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, 02/2019)
Day(s) Performed
Report Available
8 to 12 daysTest 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 x 21
86341
84182-AGNBS (if appropriate)
86256 AGNTS (if appropriate)
86255-AINCS (if appropriate)
86256-AMPIS (if appropriate)
84182-AMIBS (if appropriate)
84182-AN1BS (if appropriate)
86256-AN1TS (if appropriate)
84182-AN2BS (if appropriate)
86256-AN2TS (if appropriate)
86256-AN3TS (if appropriate)
86256-APHTS (if appropriate)
86256-CRMTS (if appropriate)
84182-CRMWS (if appropriate)
86256-DPPTS (if appropriate)
86256-GABIS (if appropriate)
86255-GFACS (if appropriate)
86256-GFATS (if appropriate)
86256-IG5TS (if appropriate)
86255-GL1CS (if appropriate)
86256-GL1TS (if appropriate)
86255-NCDCS (if appropriate)
86256-NCDTS (if appropriate)
86255-NFHCS (if appropriate)
86256-NIFTS (if appropriate)
86255-NFLCS (if appropriate)
86256-NMDIS (if appropriate)
86256-PC2TS (if appropriate)
84182-PCTBS (if appropriate)
86256-PCTTS (if appropriate)
86256 PDETS (if appropriate)
86255 T46CS (if appropriate)
86256 T46TS (if appropriate)