Voltage-Gated Potassium Channel (VGKC) Antibody with Reflex to LGI1 and CASPR2 Screen and Titer, Serum
Also known as: VGKC R
Use
Voltage-Gated Potassium Channel (VGKC) antibodies are associated with neuromuscular weakness as found in neuromyotonia (also known as Issacs syndrome) and Morvan syndrome. VGKC antibodies are also associated with paraneoplastic neurological syndromes and limbic encephalitis. However, VGKC antibody-associated limbic encephalitis may be associated with antibodies to leucine-rich, glioma-inactivated 1 protein (LGI1) or contactin-associated protein-2 (CASPR2) instead of potassium channel antigens. The clinical significance of this test can only be determined in conjunction with the patient's clinical history and related laboratory testing.
Special Instructions
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.
Limitations
A substantial number of VGKC-antibody positive cases are negative for LGI1 and CASPR2 IgG autoantibodies, not all VGKC complex antigens are known. 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.
New York Approved
Methodology
Immunoassay (Radioimmunoassay)
Biomarkers
LOINC Codes
- 41871-5
Result Turnaround Time
1-8 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
4 mL
Minimum Volume
0.5 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Separate serum from cells within 1 hour. Transfer 4 mL serum to an ARUP Standard Transport Tube.
Storage Instructions
Refrigerated.
Causes for Rejection
Plasma. Severely lipemic or icteric specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 month |
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