Ordering RecommendationRecommendations when to order or not order the test. May include related or preferred tests.
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.
Aid in diagnosis of contactin associated protein 2 (CASPR2) antibody disorders associated with acquired neuromyotonia, limbic encephalitis, painful neuropathy, and Morvan syndrome.
Use to manage antibody-positive (LGI1 or CASPR2) individual following immunotherapy and/or plasmapheresis
MnemonicUnique test identifier.
LGI1CASPR2
MethodologyProcess(es) used to perform the test.
Semi-Quantitative Indirect Fluorescent Antibody
PerformedDays of the week the test is performed.
Wed
ReportedExpected turnaround time for a result, beginning when ARUP has received the specimen.
1-8 days
New York DOH Approval StatusIndicates test has been approved by the New York State Department of Health.
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect
Serum separator tube.
Specimen Preparation
Separate serum from cells within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
Storage/Transport Temperature
Refrigerated.
Unacceptable Conditions
CSF or plasma. Contaminated, hemolyzed, or severely lipemic specimens.
Remarks
Stability
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference IntervalNormal range/expected value(s) for a specific disease state. May also include abnormal ranges.
Contactin-Associated Protein-2 Antibody, IgG with Reflex to Titer, Serum
Less than 1:10
Interpretive DataBackground information for test. May include disease information, patient result explanation, recommendations, details of testing, associated diseases, explanation of possible patient results.
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.
Compliance Category
Laboratory Developed Test (LDT)
NoteAdditional information related to the test.
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.
CPT CodesThe American Medical Association Current Procedural Terminology (CPT) codes published in ARUP's Laboratory Test Directory are provided for informational purposes only. The codes reflect our interpretation of CPT coding requirements based upon AMA guidelines published annually. CPT codes are provided only as guidance to assist clients with billing. ARUP strongly recommends that clients confirm CPT codes with their Medicare administrative contractor, as requirements may differ. CPT coding is the sole responsibility of the billing party. ARUP Laboratories assumes no responsibility for billing errors due to reliance on the CPT codes published.
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
AliasesOther names that describe the test. Synonyms.
Leucine-Rich, Glioma-Inactivated Protein 1 Antibody, IgG and Contactin-Associated Protein-2 Antibody, IgG with Reflex to Titers, Serum