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Test Code GFATC Glial Fibrillary Acidic Protein Alpha Subunit Antibody, Immunofluorescence Titer Assay, Spinal Fluid


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:

DMC2 / Dementia Autoimmune Evaluation, Spinal Fluid

ENC2 / Encephalopathy Autoimmune Evaluation, Spinal Fluid

EPC2 / Epilepsy Autoimmune Evaluation, Spinal Fluid

MAC1 / Autoimmune Myelopathy Evaluation, Spinal Fluid

 

Container/Tube: Sterile vial

Specimen Volume: 2 mL


Useful For

Reporting an end titer result in spinal fluid specimens

 

Distinguishing, in spinal fluid, autoimmune 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

Method Name

Only orderable as a reflex. For more information, see:

DMC2 / Dementia Autoimmune Evaluation, Spinal Fluid

ENC2 / Encephalopathy Autoimmune Evaluation, Spinal Fluid

EPC2 / Epilepsy Autoimmune Evaluation, Spinal Fluid

MAC1 / Autoimmune Myelopathy Evaluation, Spinal Fluid

 

Indirect Immunofluorescence Assay (IFA)

Reporting Name

GFAP IFA Titer, CSF

Specimen Type

CSF

Specimen Minimum Volume

1.5 mL

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

Antibody targeting glial fibrillary acidic protein (GFAP)-IgG is a biomarker of a subacute and progressive autoimmune meningitis, encephalitis, and myelitis that can mimic multiple sclerosis (MS) or other idiopathic inflammatory central nervous system (CNS) disorders such as sarcoidosis. Neurological manifestations include headache, optic neuropathy, transverse myelitis, cognitive decline, and cerebellar ataxia. Cerebrospinal fluid (CSF) is inflammatory. Cranial magnetic resonance (MR) imaging reveals linear perivascular enhancement oriented radially to ventricles. A paraneoplastic neurological context is common. Reported neoplasms accompanying neurological symptoms include adenocarcinomas (prostate and gastroesophageal), myeloma, melanoma, colonic carcinoid, parotid pleomorphic adenoma and teratoma. If GFAP-IgG is detected by immunofluorescence assay (IFA), it is reflexed to a test for the alpha isoform of GFAP (GFAPalpha-IgG) by cell based assay.

Reference Values

Only orderable as a reflex. For more information, see:

DMC2 / Dementia Autoimmune Evaluation, Spinal Fluid

ENC2 / Encephalopathy Autoimmune Evaluation, Spinal Fluid

EPC2 / Epilepsy Autoimmune Evaluation, Spinal Fluid

MAC1 / Autoimmune Myelopathy Evaluation, Spinal Fluid

 

<1:2

Day(s) Performed

Monday through Sunday

Report Available

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