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Test Code SP7TC Septin-7 Antibody, Tissue Immunofluorescence Titer, Spinal Fluid


Specimen Required


Only orderable as a reflex. For more information see:

-ENC2 / Encephalopathy, Autoimmune /Paraneoplastic Evaluation, Spinal Fluid

-MDC2 / Movement Disorder, Autoimmune /Paraneoplastic Evaluation, Spinal Fluid

-MAC1 / Autoimmune Myelopathy /Paraneoplastic Evaluation, Spinal Fluid 

 

Container/Tube: Sterile vial

Specimen Volume: 1.5 mL


Useful For

Detecting septin-7 IgG in cerebrospinal fluid (CSF) specimens

 

Reporting an end titer result from CSF specimens

Testing Algorithm

If the indirect immunofluorescence pattern suggests septin-7, then septin-7 antibody cell-binding assay and this test will be performed at an additional charge.

Method Name

Only orderable as a reflex. For more information see:

-ENC2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

-MAC1 / Autoimmune Myelopathy/Paraneoplastic Evaluation, Spinal Fluid

 

Indirect Immunofluorescence Assay (IFA)

Reporting Name

Septin-7 IFA Titer, CSF

Specimen Type

CSF

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
CSF Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Clinical Information

Neurological phenotypes for septin-7 IgG positive patients include encephalopathy, myelopathy, encephalomyelopathy, painful myelopolyradiculopathy, and episodic ataxia. Psychiatric symptoms are also common with encephalopathic symptoms. Septin-7 IgG is also associated with cancer and positive response to immunotherapy.

Reference Values

Only orderable as a reflex. For more information see:

-ENC2 / Encephalopathy, Autoimmune /Paraneoplastic Evaluation, Spinal Fluid

-MDC2 / Movement Disorder, Autoimmune /Paraneoplastic Evaluation, Spinal Fluid

-MAC1 / Autoimmune Myelopathy /Paraneoplastic Evaluation, Spinal Fluid

 

<1:2

Interpretation

Seropositivity for septin antibodies by immunofluorescence is consistent with a diagnosis of autoimmune disease of the central nervous system. Cell-binding assay testing for septin-7 IgG is required to confirm the diagnosis.

Cautions

Negative results for septin antibodies do not exclude neurological autoimmunity or cancer.

Method Description

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 Jul 18;4(5):e385. doi: 10.1212/NXI.0000000000000385)

Day(s) Performed

Monday through Sunday

Report Available

5 to 10 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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

86256

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SP7TC Septin-7 IFA Titer, CSF 101457-0

 

Result ID Test Result Name Result LOINC Value
616116 Septin-7 IFA Titer, CSF 101457-0