Ordering Recommendation

Not recommended.

Mnemonic

WNIL IGG

Methodology

Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Performed

Sun, Tue, Fri

Reported

1-6 days

New York DOH Approval Status

Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.

Specimen Required

Patient Preparation
Collect

CSF.

Specimen Preparation

Transfer 2 mL CSF to an ARUP Standard Transport Tube. (Min: 0.15 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Contaminated, heat-inactivated, or hemolyzed specimens.

Remarks
Stability

Ambient: 8 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval

1.29 IV or less Negative - No significant level of West Nile virus IgG antibody detected.
1.30-1.49 IV Equivocal - Questionable presence of West Nile virus IgG antibody detected.  Repeat testing in 10-14 days may be helpful.
1.50 IV or greater Positive - Presence of IgG antibody to West Nile virus detected, suggestive of current or past infection.

Interpretive Data

This test is intended to be used as a semi-quantitative means of detecting West Nile virus-specific IgG in CSF specimens in which there is a clinical suspicion of West Nile virus infection.  This test should not be used solely for quantitative purposes, nor should the results be used without correlation to clinical history or other data.  Because other members of the Flaviviridae family, such as St. Louis encephalitis virus, show extensive cross-reactivity with West Nile virus, serologic testing specific for these species should be considered.

The detection of antibodies to West Nile virus in cerebrospinal fluid may indicate central nervous system infection.  However, consideration must be given to possible contamination by blood or transfer of serum antibodies across the blood-brain barrier.

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)

Note

Hotline History

N/A

CPT Codes

86789

Components

Component Test Code* Component Chart Name LOINC
0050238 West Nile Virus Antibody IgG CSF 39572-3
* 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.

Aliases

  • Arbovirus
  • Flavivirus
  • WNV IgG, CSF
West Nile Virus Antibody, IgG by ELISA, CSF