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Voltage-Gated Potassium Channel (VGKC) Complex Antibodies: Anti LGI1 and Anti CASPR2, With Reflex to Titer, Spinal Fluid

Test Number 505713
Test number copied
CPT 86255(x2)
Synonyms
  • Autoimmune Dementia Panel Spinal Fluid
  • Paraneoplastic

Test Details

Methodology

Immunofluorescence, Immunoblot

Result Turnaround Time

4 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.

Use

Voltage-Gated Potassium Channel (VGKC) antibodies (predominately Anti-LGI1 and Anti-CASPR2) are associated with paraneoplastic neurological syndromes and limbic encephalitis. These antibodies may also be found in other conditions such as acquired neurmyotonia, painful neuropathy, Morvan's syndrome and rare tumors (e.g., thymoma, small-cell lung cancer).

This indirect fluorescent antibody assay utilizes LGI1 and CASPR2 transfected cell lines for the detection and semi-quantification of autoantibodies.

Special Instructions

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

Limitations

This test was developed and its performance characteristics determined by Labcorp in accordance with CLIA requirements. This test has not been cleared or approved by the Food and Drug Administration.

Specimen Requirements

Specimen

Cerebrospinal fluid (CSF)

Volume

2 mL

Minimum Volume

1 mL

Container

Sterile plastic tube

Stability Requirements

Temperature

Period

Room temperature

14 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Storage Instructions

Room temperature

Causes for Rejection

Gross hemolysis; grossly lipemic; gross icterus

References

van Sonderen A, Schreurs MW, Wirtz PW, Sillevis Smitt PA, Titulaer MJ. From VGKC to LG1 and Caspr2 encephalitis: The evolution of a disease entity over time. Autoimmun Rev. 2016 Oct;15(10):970-974.27485013
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
Willis MD, Jones L, Vincent A, Wheeler R, O'Callaghan P, Hamandi K. VGKC-complex antibody encephalitis. QJM. 2014 Aug;107(8):657-659.24517999
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
505713 Anti-VGKC Complex, CSF 505637 LGI1 Antibody, Cell-based IFA 90830-1
505713 Anti-VGKC Complex, CSF 505636 CASPR2 Antibody,Cell-based IFA 90820-2
Order Code505713
Order Code NameAnti-VGKC Complex, CSF
Order Loinc
Result Code505637
Result Code NameLGI1 Antibody, Cell-based IFA
UofM
Result LOINC90830-1
Order Code505713
Order Code NameAnti-VGKC Complex, CSF
Order Loinc
Result Code505636
Result Code NameCASPR2 Antibody,Cell-based IFA
UofM
Result LOINC90820-2
Reflex Table for LGI1 Antibody, Cell-based IFA
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 505609 Anti-LGI1 Antibody Titer 505609 Anti-LGI1 Antibody Titer 90831-9
Reflex 1
Order Code505609
Order NameAnti-LGI1 Antibody Titer
Result Code505609
Result NameAnti-LGI1 Antibody Titer
UofM
Result LOINC90831-9
Reflex Table for CASPR2 Antibody,Cell-based IFA
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 505608 Anti-CASPR2 Antibody Titer 505608 Anti-CASPR2 Antibody Titer 90820-2
Reflex 1
Order Code505608
Order NameAnti-CASPR2 Antibody Titer
Result Code505608
Result NameAnti-CASPR2 Antibody Titer
UofM
Result LOINC90820-2