Autoimmune Encephalitis Reflexive Panel, Serum
Ordering Recommendation

Differential evaluation of encephalitis of unknown origin with subacute onset of seizures, confusion, memory loss, and/or behavioral change. For extended version of this panel, refer to Autoimmune Encephalitis Extended Panel, Serum (3001431). For adults and patients with suspicion of cancer, additional evaluation of paraneoplastic autoantibodies is recommended; refer to Paraneoplastic Antibodies (PCCA/ANNA) by IFA with Reflex to Titer and Immunoblot (2007961).

Semi-Quantitative Indirect Fluorescent Antibody/Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Quantitative Radioimmunoassay
1-8 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Serum Separator Tube (SST). 
Specimen Preparation
Separate from cells ASAP or within 2 hours of collection. Transfer three 1 mL aliquots of serum to individual ARUP Standard Transport Tubes. (Min: 0.5 mL/aliquot) 
Storage/Transport Temperature
Unacceptable Conditions
Amniotic fluid, ocular fluid, peritoneal fluid, synovial fluid, CSF, or plasma. Contaminated, hemolyzed, icteric, or lipemic specimens. 
After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 1 month (avoid repeated freeze/thaw cycles) 
Reference Interval
Test Number
Reference Interval
2004221N-methyl-D-Aspartate Receptor Antibody, IgG, Serum with Reflex to Titer< 1:10
2001771Glutamic Acid Decarboxylase Antibody0.0-5.0 IU/mL
2004890Voltage-Gated Potassium Channel (VGKC) Antibody, Serum
Negative31 pmol/L or less
Indeterminate32-87 pmol/L
Positive88 pmol/L or greater

2003036Aquaporin-4 Receptor AntibodyEffective October 3, 2016
Negative2.9 U/mL or less
Positive3.0 U/mL or greater

2013320Aquaporin-4 Receptor Antibody, IgG by IFA with Reflex to Titer, SerumLess than 1:10
2009456Leucine-Rich, Glioma-Inactivated Protein 1 Antibody, IgG with Reflex to Titer, SerumLess than 1:10
2009452Contactin-Associated Protein-2 Antibody, IgG with Reflex to Titer, SerumLess than 1:10

Interpretive Data
Refer to report

Statement D: Compliance Statement D: For laboratory tests using a manufactured RUO kit. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

AQP4: If AQP4 antibody IgG by ELISA is positive, then AQP4 antibody IgG by IFA will be added. If AQP4 antibody IgG by IFA is positive, then an AQP4 antibody IgG titer will be added. Additional charges apply.
VGKC: If VGKC is Indeterminate or Positive, LGI1 Antibody IgG and CASPR2 Antibody IgG will be added. If LGI1 antibody IgG is positive, then LGI1 antibody IgG titer will be added. If CASPR2 antibody IgG is positive, then CASPR2 antibody IgG titer will be added. Additional charges apply.
NMDA: If NMDA antibody IgG is positive, then an NMDA antibody IgG titer is reported. Additional charges apply.
Hotline History
View Hotline History
CPT Code(s)
83519; 83516; 86255; 86341; if reflexed add 86255 x2, if further reflexed add 86256 per titer; if reflexed add 86256; if reflexed add 86255, if further reflexed add 86256
Component Test Code*Component Chart NameLOINC
2001772Glutamic Acid Decarboxylase Antibody56540-8
2003121Aquaporin-4 Receptor Antibody61430-5
2004222N-methyl-D-Aspartate Receptor Ab, Serum80221-5
2004890Voltage-Gated Potassium Channel Ab, Ser41871-5
* 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 view this test within the Laboratory Test Directory found at