Encephalopathy-Autoimmune Evaluation, CSF

Test Code

94705

CPT Codes
⁠⁠⁠⁠⁠⁠⁠86255 (x21), 86341<br>Restricted Client Code

Includes

If client requests or if immunofluorescence (IFA) patterns suggest collapsin response-mediator protein-5-IgG (CRMP-5-IgG), then CRMP-5-IgG Western blot is performed at an additional charge (CPT code(s): 86256)

If IFA patterns suggest amphiphysin antibody, then amphiphysin immunoblot is performed at an additional charge (CPT code(s): 84182)

If IFA pattern suggests antiglial nuclear antibody (AGNA-1) antibody, then AGNA-1 immunoblot is performed at an additional charge (CPT code(s): 84182)

If IFA pattern suggests antineuronal nuclear antibody (ANNA-1) antibody, then ANNA-1 immunoblot is performed at an additional charge (CPT code(s): 84182)

If IFA pattern suggests ANNA-2 antibody, then ANNA-2 immunoblot is performed at an additional charge (CPT code(s): 84182)

If IFA pattern suggests Purkinje cytoplasmic antibody (PCA-1) antibody, then PCA-1 immunoblot is performed at an additional charge (CPT code(s): 84182)

If IFA pattern suggests PCA-Tr antibody, then PCA-Tr immunoblot is performed at an additional charge (CPT code(s): 84182)

If IFA pattern suggests IgLON5 antibody, then IgLON5 IFA titer IgLON5 cell-binding assay (CBA) is performed at an additional charge (CPT code(s): 86255, 86256)

If IFA pattern suggests alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-receptor antibody, and AMPA-receptor antibody CBA is positive, then AMPA-receptor antibody IFA titer assay is performed at an additional charge (CPT code(s): 86256)

If IFA pattern suggests gamma-aminobutyric acid B (GABA-B)-receptor antibody, and GABA-B-receptor antibody CBA is positive, then GABA-B-receptor antibody IFA titer assay is performed at an additional charge (CPT code(s): 86256)

If IFA pattern suggests glial fibrillary acidic protein (GFAP) antibody, then GFAP IFA titer and GFAP CBA are performed at an additional charge (CPT code(s): 86256, 86255)

If IFA pattern suggests N-methyl-D-aspartate (NMDA)-receptor antibody, and NMDA-receptor antibody CBA is positive, then NMDA-receptor antibody IFA titer assay is performed at an additional charge (CPT code(s): 86256)

If IFA pattern suggests dipeptidyl-peptidase-like protein-6 (DPPX) antibody, then DPPX antibody CBA and DPPX titer are performed at an additional charge (CPT code(s): 86255, 86256)

If IFA pattern suggests metabotropic glutamate receptor 1 (mGluR1) antibody, then mGluR1 antibody CBA and mGluR1 titer are performed at an additional charge (CPT code(s): 86255, 86256)

If IFA pattern suggests neuronal intermediate filament (NIF) antibody, then alpha internexin CBA, NIF heavy chain CBA, NIF light chain CBA, and NIF titer are performed at an additional charge (CPT code(s): 86255, 86256)

Preferred Specimen

4 mL CSF collected in a sterile vial

Minimum Volume

2 mL

Instructions

New Ordering Guidance
This test is intended to be ordered for adult patients.
-If this test is ordered for a patient younger than 18 years of age, it will be canceled and automatically reordered by the laboratory as PCDEC / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Spinal Fluid.
-The pediatric autoimmune CNS disorders evaluation is part of an evolving approach to testing for autoimmune neurological disorders using phenotypic-specific evaluations that include multiple antibodies known for their disease association

Transport Temperature

Refrigerated (cold packs)

Specimen Stability

Room temperature: 72 hours
Refrigerated: 28 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Grossly lipemic • Grossly icteric

Methodology
Indirect Immunofluorescence Assay • Radioimmunoprecipitation Assay • Cell Binding Assay • Western Blot • Flow Cytometry

Setup Schedule

Set up: Daily; Report available: 5-10 days

Reference Range

See Laboratory Report

Clinical Significance

Evaluating new onset encephalopathy (noninfectious or metabolic) comprising confusional states, psychosis, delirium, memory loss, hallucinations, movement disorders, sensory or motor complaints, seizures, dyssomnias, ataxias, nausea, vomiting, inappropriate antidiuresis, coma, dysautonomias, or hypoventilation in spinal fluid specimens

The following accompaniments should increase of suspicion for autoimmune encephalopathy:
-Headache
-Autoimmune stigmata (personal or family history or signs of diabetes mellitus, thyroid disorder, vitiligo, poliosis [premature graying], myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus)
-History of cancer
-Smoking history (over 20 pack-years) or other cancer risk factors
-Inflammatory cerebrospinal fluid (or isolated protein elevation)
-Neuroimaging signs suggesting inflammation

Evaluating limbic encephalitis (noninfectious)

Directing a focused search for cancer

Investigating encephalopathy appearing in the course or wake of cancer therapy and not explainable by metastasis or drug effect

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.