Glial Fibrillary Acidic Protein Alpha Subunit Antibody, Immunofluorescence Titer Assay, Spinal Fluid
Use
This test is useful for reporting an end titer result in spinal fluid specimens to distinguish autoimmune GFAP astrocytopathy from infectious meningoencephalitis and idiopathic inflammatory CNS disorders such as multiple sclerosis, vasculitis, and sarcoidosis. It alerts the clinician that the patient may have an immune-mediated, steroid-responsive disorder and prompts a search for a malignancy.
Special Instructions
This test is only orderable as a reflex through evaluations such as DMC2, ENC2, EPC2, and MAC1. Relevant clinical information and ordering provider details are necessary when ordering this test.
Limitations
Negative results do not exclude the diagnosis of autoimmune meningoencephalomyelitis or cancer. Improper specimen collection and handling or inappropriate test selection may cause diagnostic confusion.
New York Approved
Methodology
Immunoassay (Indirect Immunofluorescence Assay (IFA))
Biomarkers
LOINC Codes
- 93421-6
- 93421-6
Result Turnaround Time
10 days
Related Documents
For more information, please review the documents below
Specimen
Cerebrospinal Fluid
Volume
2 mL
Minimum Volume
1.5 mL
Container
Sterile vial
Causes for Rejection
Gross hemolysis, gross lipemia, gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 28 days |
| Frozen | 28 days |