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HelpOrder Code GFATS Glial Fibrillary Acidic Protein Alpha Subunit Antibody, Immunofluorescence Titer Assay, Serum
Necessary Information
Provide the following information:
-Relevant clinical information
-Ordering provider name, phone number, mailing address, and e-mail address
Specimen Required
Only orderable as a reflex. For more information see:
ENS2 / Encephalopathy, Autoimmune Evaluation Serum
DMS2 / Dementia, Autoimmune Evaluation, Serum
EPS2 / Epilepsy, Autoimmune Evaluation, Serum
MAS1 / Autoimmune Myelopathy Evaluation, Serum
Useful For
Reporting an end titer result in serum specimens
Distinguishing autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy from infectious meningoencephalitis and idiopathic inflammatory central nervous system (CNS) disorders such as multiple sclerosis, vasculitis and sarcoidosis, disorders commonly considered in the differential diagnosis
Alerting the clinician that the patient has an immune-mediated, steroid-responsive disorder and to search for a malignancy
Testing Algorithm
If immunofluorescence assay (IFA) pattern suggests GFAP, then GFAP IFA titer and GFAP cell-binding assay (CBA) are performed at an additional charge.
Method Name
Only orderable as a reflex. For more information see:
ENS2 / Encephalopathy, Autoimmune Evaluation Serum
DMS2 / Dementia, Autoimmune Evaluation, Serum
EPS2 / Epilepsy, Autoimmune Evaluation, Serum
MAS1 / Autoimmune Myelopathy Evaluation, Serum
Indirect Immunofluorescence Assay (IFA)
Reporting Name
GFAP IFA Titer, SSpecimen Type
SerumSpecimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 28 days |
| Frozen | 28 days | |
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Reference Values
Only orderable as a reflex. For more information see:
ENS2 / Encephalopathy, Autoimmune Evaluation Serum
DMS2 / Dementia, Autoimmune Evaluation, Serum
EPS2 / Epilepsy, Autoimmune Evaluation, Serum
MAS1 / Autoimmune Myelopathy Evaluation, Serum
<1:240
Method Description
The patient's specimen is tested by a standardized immunofluorescence assay that uses a composite frozen section of mouse cerebellum, kidney, and gut tissues. After incubation with the specimen and washing, fluorescein-conjugated goat-antihuman IgG is applied. Neuron-specific autoantibodies are identified by their characteristic fluorescence staining patterns. Specimens that are scored positive for any neuronal nuclear or cytoplasmic autoantibody are titrated. 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. Published 2017 Jul 18. doi:10.1212/NXI.0000000000000385)
Day(s) Performed
Monday through Sunday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
86256