The differential diagnosis of patients presenting with mixed cerebellar and sensory ataxia and myeloneuropathy
Reporting an end titer result from spinal fluid specimens
If the indirect immunofluorescence pattern suggests AP3B2 (adaptor protein 3 beta2), then AP3B2 antibody cell-binding assay (CBA) and this test will be performed at an additional charge.
Only orderable as part of a profile. For more information see:
-MAC1 / Myelopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
Indirect Immunofluorescence Assay (IFA)
NAPTB
Adaptor related protein complex 3 beta 2 subunit
EIEE48
Adaptor related protein complex 3 subunit beta 2
If the indirect immunofluorescence pattern suggests AP3B2 (adaptor protein 3 beta2), then AP3B2 antibody cell-binding assay (CBA) and this test will be performed at an additional charge.
CSF
Only orderable as part of a profile. For more information see:
-MAC1 / Myelopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
Container/Tube: Sterile vial
Preferred: Vial number 1
Acceptable: Any vial
Specimen Volume: 1.5 mL
See Specimen Required
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
CSF | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 72 hours |
The differential diagnosis of patients presenting with mixed cerebellar and sensory ataxia and myeloneuropathy
Reporting an end titer result from spinal fluid specimens
If the indirect immunofluorescence pattern suggests AP3B2 (adaptor protein 3 beta2), then AP3B2 antibody cell-binding assay (CBA) and this test will be performed at an additional charge.
AP3B2 (adaptor protein 3 beta2)-IgG is a marker of an autoimmune disorder unified by gait instability as the predominant neurologic presentation. Patients present with either cerebellar, dorsal column, or sensory neuronal dysfunction. Clinical improvement following treatment has been reported. AP3B2 autoimmunity appears rare, is accompanied by ataxia (sensory or cerebellar), and is potentially treatable.
Only orderable as part of a profile. For more information see:
-MAC1 / Myelopathy, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
-MDC2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid
<1:2
A positive result supports a diagnosis of neurological autoimmunity. Neurological phenotypes encountered include cerebellar ataxia, spinocerebellar ataxia, myelopathy, sensory neuronopathy and autonomic neuropathy. Neurological stabilization or improvement may occur with immune therapy.
A negative result does not exclude neurological autoimmunity or cancer.
Honorat JA, Lopez-Chiriboga AS, Kryzer, TJ, et al: Autoimmune gait disturbance accompanying adaptor protein-3B2-IgG. Neurology. 2019 Sep 3;93(10):e954-e963
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)
Monday through Sunday
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.
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
APBTC | AP3B2 IFA Titer, CSF | 101908-2 |
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.
|
---|---|---|
616110 | AP3B2 IFA Titer, CSF | 101908-2 |