Ordering Recommendation

Differential evaluation of encephalitis of unknown origin with subacute onset of seizures, confusion, memory loss, and/or behavioral change. Detects antibodies in addition to those included in Autoimmune Encephalitis Reflexive Panel, Serum (2013601). Testing for LGI1 and CASPR2 antibodies is always performed rather than only as a reflex. For adults and patients with suspicion of cancer, additional evaluation of paraneoplastic autoantibodies is recommended; refer to Paraneoplastic Reflexive Panel (3002929).

Mnemonic

ENCEPH EXT

Methodology

Semi-Quantitative Cell-Based Indirect Fluorescent Antibody/Quantitative Radioimmunoassay/Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Performed

Tue

Reported

3-10 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation
Collect

Serum Separator Tube (SST).

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer three (3) 1 mL serum aliquots to ARUP Standard Transport Tubes. (Min: 0.5 mL/aliquot)

Storage/Transport Temperature

Frozen.

Unacceptable Conditions

Contaminated specimens.

Remarks
Stability

After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 30 days (avoid repeated freeze/thaw cycles)

Reference Interval

Test Number
Components
Reference Interval
  Glutamic Acid Decarboxylase Antibody 0.0-5.0 IU/mL
  N-methyl-D-Aspartate Receptor Ab, Serum Less than 1:10
  Voltage-Gated Potassium Channel Ab, Ser 31 pmol/L or less
  CASPR2 Ab IgG Screen by IFA, Serum Less than 1:10
  LGI1 Ab IgG Screen by IFA, Serum Less than 1:10
  Neuromyelitis Optica/AQP4-IgG, Serum Less than 1:10
  AMPA Receptor Ab IgG Screen, Serum Less than 1:10
  GABA-B Receptor Ab IgG Screen, Serum Less than 1:10
  MOG Antibody IgG Screen, Serum Less than 1:10
  DPPX Ab IgG CBA IFA Screen, Serum Less than 1:10

Interpretive Data

Refer to report.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.


Component Interpretive Data (pmol/L)
Voltage-Gated Potassium Channel Ab, Ser 31 or less: Negative
32-87: Indeterminate
88 or greater: Positive

Compliance Category

Laboratory Developed Test (LDT)

Note

If N-methyl-D-Aspartate Receptor Antibody is positive, then a titer will be added. Additional charges apply.
If Aquaporin-4 Receptor antibody IgG is positive, then a titer will be added. Additional charges apply.
If LGI1 antibody IgG is positive, then LGI1 antibody IgG titer will be added. Additional charges apply.
If CASPR2 antibody IgG is positive, then CASPR2 antibody IgG titer will be added. Additional charges apply.
If AMPAR Antibody IgG is positive, then a titer will be added. Additional charges apply.
If GABABR Antibody IgG is positive, then a titer will be added. Additional charges apply.
If MOG Antibody IgG is positive, then a titer will be added. Additional charges apply.
If DPPX Antibody IgG is positive, then a titer will be added. Additional charges apply.

Hotline History

N/A

CPT Codes

83519; 86052; 86341; 86362; 86255 x6; if reflexed, add 86256 x8

Components

Component Test Code* Component Chart Name LOINC
2001772 Glutamic Acid Decarboxylase Antibody 56540-8
2004222 N-methyl-D-Aspartate Receptor Ab, Serum 80221-5
2004890 Voltage-Gated Potassium Channel Ab, Ser 41871-5
2009453 CASPR2 Ab IgG Screen by IFA, Serum 82979-6
2009457 LGI1 Ab IgG Screen by IFA, Serum 82978-8
2013322 Neuromyelitis Optica/AQP4-IgG, Serum 63439-4
3001261 AMPA Receptor Ab IgG Screen, Serum 82733-7
3001271 GABA-B Receptor Ab IgG Screen, Serum 93428-1
3001278 MOG Antibody IgG Screen, Serum 91545-4
3004361 DPPX Ab IgG CBA IFA Screen, Serum 94676-4
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

Autoimmune Encephalitis Extended Panel, Serum