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, CSFSpecimen Type
CSFSpecimen 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 daysSpecimen Retention Time
28 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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 |