Voltage-Gated Potassium Channel (VGKC) Antibody with Reflex to LGI1 and CASPR2 Screen and Titer
Ordering Recommendation

Screening test for voltage-gated potassium channel (VGKC) antibody receptor complex-associated autoantibodies with test reflex to CASPR2 and LGI1 antibodies. Antibodies are associated with acquired neuromyotonia, limbic encephalitis, painful neuropathy, Morvan syndrome, and rare tumors (eg, thymoma, small-cell lung cancer).

Quantitative Radioimmunoassay/Semi-Quantitative Indirect Fluorescent Antibody
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
Plain red or serum separator tube. 
Specimen Preparation
Separate serum from cells within 1 hour. Transfer 4 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL) 
Storage/Transport Temperature
Unacceptable Conditions
Plasma. Severely lipemic or icteric specimens. 
After separation from cells: Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month (avoid repeated freeze/thaw cycles) 
Reference Interval
Test Number
Reference Interval
2004890Voltage-Gated Potassium Channel (VGKC) Antibody, Serum
Negative31 pmol/L or less
Indeterminate32-87 pmol/L
Positive88 pmol/L or greater

2009456Leucine-Rich, Glioma-Inactivated Protein 1 Antibody, IgG with Reflex to TiterLess than 1:10
2009452Contactin-Associated Protein-2 Antibody, IgG with Reflex to TiterLess than 1:10

Interpretive Data

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.

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.
Hotline History
CPT Code(s)
83519; if reflexed add 86255 x2; if reflexed add 86256 per titer
Component Test Code*Component Chart NameLOINC
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 click the sidebar link to access the Interface Map.