Voltage-Gated Potassium Channel Antibodies

Label Mnemonic:	VGKCA
Epic code:	LAB7733
Downtime form:	A-1a Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Commercial Mailout Laboratory
6240-8 RCP
356-8593

Specimen(s):

Serum

Collection Medium:

	and
Red top tube 5 mL (Clot Activator)	and	Red top tube 5 mL (Clot Activator)

Minimum:

Preferred Minimum: 4 mL serum
Absolute Minimum: 0.5 mL serum

Rejection Criteria:

Plasma. Grossly lipemic or icteric specimens.

Turn Around Time:

1-8 days upon receipt at reference laboratory.

Reference Range:

Negative:       31 pmol/L or less  
Indeterminate:  32-87 pmol/L  
Positive:       88 pmol/L or greater

Interpretive Data:

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 (Caspr-2) 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.

Methodology:

Quantitative Radioimmunoassay

CPT Code:

83519