Test Catalog

Test Id : SPPC

Stiff-Person Spectrum Disorders Evaluation, including Progressive Encephalomyelitis with Rigidity and Myoclonus, Spinal Fluid

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with suspected stiff-person syndrome (classical or focal forms, such as stiff-limb or stiff-trunk) and progressive encephalomyelitis with rigidity and myoclonus using spinal fluid specimens

Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test Id Reporting Name Available Separately Always Performed
SPPCI Stiff-Person/PERM Interp, CSF No Yes
AMPHC Amphiphysin Ab, CSF No Yes
DPPCC DPPX Ab CBA, CSF No Yes
GD65C GAD65 Ab Assay, CSF Yes Yes
GLYCC Glycine Alpha1 LCBA, CSF Yes Yes

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
AMIBC Amphiphysin Immunoblot, CSF No No
DPPTC DPPX Ab IFA Titer, CSF No No

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If indirect immunofluorescence assay (IFA) pattern suggests amphiphysin antibody, then amphiphysin immunoblot will be performed at an additional charge.

 

If dipeptidyl-peptidase-like protein-6 (DPPX) cell bound assay is positive, then DPPX antibody IFA titer will be performed at an additional charge.

Method Name
A short description of the method used to perform the test

AMPHC, DPPTC: Indirect Immunofluorescence Assay (IFA)

AMIBC: Immunoblot (IB)

DPPCC: Cell-Binding Assay (CBA)

GD65C: Radioimmunoassay (RIA)

GLYCC: Live Cell-Binding Assay (LCBA) 

SPPCI: Medical Interpretation

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Stiff-Person/PERM Eval, CSF

Aliases
Lists additional common names for a test, as an aid in searching

PERM

Progressive encephalomyelitis

Spinal interneuronitis

Stiff-man

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If indirect immunofluorescence assay (IFA) pattern suggests amphiphysin antibody, then amphiphysin immunoblot will be performed at an additional charge.

 

If dipeptidyl-peptidase-like protein-6 (DPPX) cell bound assay is positive, then DPPX antibody IFA titer will be performed at an additional charge.

Specimen Type
Describes the specimen type validated for testing

CSF

Ordering Guidance

This test should not be requested in 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
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Container/Tube: Sterile Vial

Specimen Volume: 3 mL

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

2 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
CSF Refrigerated (preferred) 28 days
Frozen 28 days
Ambient 72 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with suspected stiff-person syndrome (classical or focal forms, such as stiff-limb or stiff-trunk) and progressive encephalomyelitis with rigidity and myoclonus using spinal fluid specimens

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If indirect immunofluorescence assay (IFA) pattern suggests amphiphysin antibody, then amphiphysin immunoblot will be performed at an additional charge.

 

If dipeptidyl-peptidase-like protein-6 (DPPX) cell bound assay is positive, then DPPX antibody IFA titer will be performed at an additional charge.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Stiff-person spectrum disorders include classical stiff-person syndrome, focal stiff-person forms (stiff-limb and stiff-trunk) and a severe encephalomyelitic form known as progressive encephalomyelitis with rigidity and myoclonus (PERM). Paraneoplastic and idiopathic autoimmune causes may be differentiated by a neuronal IgG antibody profile. The unifying clinical and electrophysiologic characteristic is central nervous system hyperexcitability. Clinical manifestations include stiffness, spasms, heightened startle responses, and falls. For the classical stiff-person form, the low back and lower extremities are principally affected. The stiff-limb phenotype may affect one or more limbs without truncal involvement. Truncal manifestations include low back spasms and deformity, and sudden chest wall spasms with breathing difficulties. Patients with PERM, in addition, have encephalopathy (often with seizures), myoclonus (muscle jerking), and dysautonomia. The most common IgG biomarker detected in stiff-person spectrum is glutamic acid decarboxylase 65 (GAD65) antibody. These patients generally have a classical or limited stiff-person form, almost always have antibody values above 20.0 nmol/L, have accompanying non-neurological autoimmune disease in 50% (type 1 diabetes and thyroid disease being most common), and almost always without accompanying cancer. Amphiphysin-IgG positivity is most commonly encountered in patients with occult breast adenocarcinoma presenting with limb stiffness and spasms; neurogenic changes are usually also detectable on clinical exam and electromyography. Glycine receptor (GlyR [alpha1 subunit]) autoimmunity patients present more commonly with PERM or stiff-limb phenotype, rather than the classical stiff-person form. Associated neoplasms in GlyR antibody positive patients include thymoma, but a general search for age- and sex-pertinent cancers should also be undertaken. Dipeptidyl-peptidase-like protein-6 (DPPX) antibody is associated with diverse central and autonomic presentations including PERM. B-cell blood dyscrasias should be tested for in DPPX-IgG positive cases. All stiff-person spectrum patients, both seropositive and seronegative may be immune therapy responsive. GlyR-IgG may be predictive of immune therapy response, including in patients with coexisting GAD65 antibody.

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.

AMPHIPHYSIN ANTIBODY

<1:2

 

DIPEPTIDYL-PEPTIDASE-LIKE PROTEIN-6 ANTIBODY CELL BINDING ASSAY (CBA)

Negative

 

GLUTAMIC ACID DECARBOXYLASE 65 ANTIBODY ASSAY

=0.02 nmol/L

 

 

GLYCINE RECEPTOR ALPHA1 IgG, CBA

Negative

 

AMPHIPHYSIN IMMUNOBLOT

Negative

 

DIPEPTIDYL-PEPTIDASE-LIKE PROTEIN IMMUNOFLUORESCENCE TITER

<1:2

Interpretation
Provides information to assist in interpretation of the test results

Spinal fluid antibody positivity supports the clinical diagnosis of stiff-person spectrum disorder (classical stiff-person, stiff-limb, stiff-trunk or progressive encephalomyelitis with rigidity and myoclonus). A paraneoplastic basis should be considered.

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 stiff-person spectrum disorder or progressive encephalomyelitis with rigidity and myoclonus (PERM).Glutamic acid decarboxylase 65 (GAD65) antibody positive values below 20 nmol/L should be interpreted with caution. Lower values are encountered in 8% of the general population. However, GAD65 autoimmunity (any antibody value) is associated with other autoimmune diseases that can cause neurological symptoms including type 1 diabetes, pernicious anemia, hypothyroidism, and adrenal insufficiency.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Hinson SR, Lopez-Chiriboga AS, Bower JH, et al: Glycine receptor modulating antibody predicting treatable stiff-person spectrum disorders. Neurol Neuroimmunol Neuroinflamm. 2018;5:e438

2. Hutchinson M, Waters P, McHugh J, et al: Progressive encephalomyelitis, rigidity, and myoclonus: a novel glycine receptor antibody. Neurology. 2008;71:1291-1292

3. Martinez-Hernandez E, Arino H, McKeon A, et al: Clinical and immunologic investigations in patients with stiff-person spectrum disorder. JAMA Neurol. 2016;73:714-720

4. McKeon A, Martinez-Hernandez E, Lancaster E, et al: Glycine receptor autoimmune spectrum with stiff-man syndrome phenotype. JAMA Neurol. 2013;70:44-50

5. McKeon A, Robinson MT, McEvoy KM, et al: Stiff-man syndrome and variants: clinical course, treatments, and outcomes. Arch Neurol. 2012 Feb;69(2):230-8

6. Pittock SJ, Lucchinetti CF, Parisi JE, et al: Amphiphysin autoimmunity: paraneoplastic accompaniments. Ann Neurol. 2005;58(1):96-107

7. Pittock SJ, Yoshikawa H, Ahlskog JE, et al: Glutamic acid decarboxylase autoimmunity with brainstem, extrapyramidal and spinal cord dysfunction. Mayo Clin Proc. 2006;81:1207-1214

8. Tobin WO, Lennon VA, Komorowski L, et al: DPPX potassium channel antibody: frequency, clinical accompaniments, and outcomes in 20 patients. Neurology. 2014;83:1797-1803

9. 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 December;73(12):1161-1166

Method Description
Describes how the test is performed and provides a method-specific reference

Indirect Immunofluorescence Assay:

The patient's sample is tested by a standardized immunofluorescence assay (IFA) 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.(Pittock SJ, Kryzer TJ, Lennon VA: Paraneoplastic antibodies coexist and predict cancer, not neurological syndrome. Ann Neurol. 2004;56:715-719; Honorat JA, Komorowski L, Josephs KA, et al: IgLON5 antibody: neurological accompaniments and outcomes in 20 patients. Neurol Neuroimmunol Neuroinflamm. 2017 Jul 18;4(5):e385. doi: 10.1212/NXI.0000000000000385)

 

Radioimmunoassay:

Duplicate aliquots of patient specimen are incubated with I(125)-labeled antigen. Immune complexes, formed by adding secondary (goat)-antihuman immunoglobulin, are pelleted by centrifugation and washed. Gamma emission from the washed pellet is counted, and mean counts per minute (cpm) are compared with results yielded by high-positive and -negative control sera. Specimen yielding cpm higher than the background cpm yielded by normal human specimen are retested to confirm positivity and titrated as necessary to obtain a value in the linear range of the assay. The antigen binding capacity (nmol per liter) is calculated from the cpm precipitated at a dilution yielding a linear range value.(Griesmann GE, Kryzer TJ, Lennon VA: Autoantibody profiles of myasthenia gravis and Lambert-Eaton myasthenic syndrome. In: Rose NR, Hamilton RG, et al 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 Nov;72[11]:1304-1312 doi: 10.1001/jamaneurol.2015.2378)

 

Immunoblot:

All steps are performed at ambient temperature (18-28 degrees C) utilizing the EUROBlot One instrument.

 

Diluted patient specimen (1:12.5) is added to test strips (strips containing recombinant antigen manufactured and purified using biochemical methods) in individual channels and incubated for 30 minutes. Positive specimens will bind to the purified recombinant antigen and negative specimens will not bind. Strips are washed to remove unbound antibodies and then incubated with anti-human IgG antibodies (alkaline phosphatase-labelled) 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 Apr 4;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)

 

Live Cell-Binding Assay :

This assay utilizes the T-REx System (Thermo Fisher). Expression of the glycine receptor alpha-1-subunit is repressed in the absence of tetracycline or doxycycline and induced in the presence of tetracycline or doxycycline.

 

HEK293 cells stably expressing the tetracycline repressor and stably transfected with a plasmid encoding the alpha-1-subunit of the glycine receptor, under control of doxycycline, are grown in wells of a chamber slide. Twenty-four hours prior to the assay, the wells on the bottom half of the slide are treated with culture media including doxycycline. After 24 hours, patient sample will be added to the living HEK293 cells held on ice. Bound IgG will be detected using a fluorophore conjugated anti-human IgG secondary antibody. Patient samples with IgG specific antibodies for the glycine receptor will be positive on doxycycline-treated cells and negative on cells not treated with doxycycline.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

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.

AMPHC, DPPTC, GD65C:

Monday through Sunday

 

AMIBC:

Monday through Friday

 

DPPCC:

Monday through Thursday, Sunday

 

GLYCC:

Thursday

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.

5 to 10 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

28 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

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 Regional Manager. 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. This test 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.

86255 x 3

86341

84182-AMIBC (if appropriate)

86256-DPPTC (if appropriate)

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
SPPC Stiff-Person/PERM Eval, CSF 94712-7
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.
5906 Amphiphysin Ab, CSF 94354-8
21702 GAD65 Ab Assay, CSF 94359-7
64934 DPPX Ab CBA, CSF 94283-9
606973 Glycine Alpha1 LCBA, CSF 96497-3
614602 Stiff-Person/PERM Interp, CSF 69048-7

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Create a PDF

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports