Leucine-Rich, Glioma-Inactivated Protein 1 Antibody, IgG CBA-IFA with Reflex to Titer, Serum
Ordering Recommendation
Aid in diagnosis of leucine-rich glioma inactivated 1 protein (LGI1) antibody disorders associated with limbic encephalitis, hyponatremia, and myoclonic movements. Disorders are rarely associated with tumors. Use to manage antibody-positive (LGI1) individual following immunotherapy and/or plasmapheresis.
Mnemonic
Methodology
Semi-Quantitative Cell-Based Indirect Fluorescent Antibody
Performed
Wed
Reported
1-8 days
New York DOH Approval Status
Specimen Required
Serum separator tube.
Separate serum from cells within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
Refrigerated.
CSF or plasma. Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference Interval
Less than 1:10
Interpretive Data
Leucine-rich, glioma-inactivated 1 protein (LGI1) IgG antibody may occur as part of the voltage-gated potassium channel (VGKC) complex antibodies.
The presence of LGI1 IgG antibody is mainly associated with limbic encephalitis, hyponatremia, and myoclonic movements. LGI1 IgG antibody is rarely associated with tumors but may occur infrequently in Morvan syndrome, neuromyotonia, and idiopathic epilepsy. The full-spectrum of clinical disorders associated with the LGI1 IgG antibody continues to be defined. Results should be interpreted in correlation with the patient's clinical history and other laboratory findings.
This indirect fluorescent antibody assay utilizes leucine-rich, glioma-inactivated 1 protein (LGI1) transfected cell lines for the detection and semi-quantification of the LGI1 IgG antibody.
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.
Laboratory Developed Test (LDT)
Note
If LGI1 antibody IgG is positive, then LGI1 antibody IgG titer will be added. Additional charges apply.
Hotline History
Hotline History
CPT Codes
86255; if reflexed, add 86256
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
2009457 | LGI1 Ab IgG Screen by IFA, Serum | 82978-8 |