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Anti-Leucine-Rich, Glioma-Inactivated Protein 1 (LGI1), Serum

Test Number 505355
Test number copied
CPT 86255

Test Details

Methodology

Immunofluorescence (IFA)

Result Turnaround Time

3 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Documents

Use

Leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis is a rare autoimmune voltage-gated potassium channel complex (VGKC) antibody-associated limbic encephalitis. Specifically, it is classified as an ant neuronal surface antigen- or ant synaptic protein-associated autoimmune encephalitis. In addition to the common symptoms of limbic encephalitis such as cognitive impairment, seizures, and psychiatric disorders, this disease is also associated with faciobrachial dystonic seizure (FBDA) and refractory hyponatremia. Unlike other limbic encephalirides, LGI1 antibody encephalitis is rarly accompanied by tumors and shows a good response to immunotherapy.

This test works as an aid in the diagnosis of LGI1 antibody disorders. This test is also useful in managing antibody-positive (LGI1) individual following immunotherapy and/or plasmapheresis.

This indirect fluorescent antibody assay utilizes LGI1 transfected cell lines for the detection and semi-quantification of the LGI1 IgG antibody.

Special Instructions

If reflex test is performed, additional charges/CPT code(s) may apply.

Limitations

Results should not be used as a diagnostic procedure without confirmation of the diagnosis by another medically established diagnostic product or procedure.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Specimen Requirements

Specimen

Serum

Volume

2 mL

Minimum Volume

1 mL (Note: This volume does not allow for repeat testing.)

Container

Gel-barrier tube, red-top tube, serum gel tube, serum transfer tube

Stability Requirements

TemperaturePeriod
Room temperature14 days
Refrigerated14 days
Frozen14 days
Freeze/thaw cyclesStable x3

Storage Instructions

Room temperature

Causes for Rejection

CSF or plasma; contaminated, hemolyzed, or severely lipemic specimens

References

Bing-Lei W, Jia-Hua Z, Yan L, et al. Three cases of antibody-LGI1 limbic encephalitis and review of literature. Int J Neurosci. 2019 Jul;129(7):642-648.30112956
Michael S, Waters P, Irani SR. Stop testing for auto-antibodies to the VGKC-complex: only request LGI1 and CASPR2. Pract Neurol. 2020 Oct;20(5):377-384.32595134
van Sonderen A, Petit-Pedrol M, Dalmu J, Titulaer MJ. The value of LGI1, CASPR2 and voltage-gated potassium channel antibodies in encephalitis. Nat Rev Neurol. 2017 May;13(5):290-301.28418022
Zuliani L, Nosadini M, Gastaldi M, et al. Management of antibody-mediated autoimmune encephalitis in adults and children: literature review and consensus-based practical recommendations. Neurol Sci. 2019 Oct;40(10):2017-2030.31161339

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
505355 Anti-LGI1, Serum 94288-8 505356 LGI1 Antibody, Cell-based IFA 82978-8
Order Code505355
Order Code NameAnti-LGI1, Serum
Order Loinc94288-8
Result Code505356
Result Code NameLGI1 Antibody, Cell-based IFA
UofM
Result LOINC82978-8
Reflex Table for LGI1 Antibody, Cell-based IFA
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 505357 Anti-LGI1 Antibody Titer,Serum 505357 Anti-LGI1 Antibody Titer,Serum 90831-9
Reflex 1
Order Code505357
Order NameAnti-LGI1 Antibody Titer,Serum
Result Code505357
Result NameAnti-LGI1 Antibody Titer,Serum
UofM
Result LOINC90831-9