Test Code LAB886 Legionella Antigen, Random, Urine
Reporting Name
Legionella Ag, USCH Clinical System Name: Legionella Urinary Antigen
Useful For
An adjunct to culture for the detection of past or current Legionnaires disease (Legionella pneumophila serogroup 1)
Ordering Guidance
This assay has been verified using urine specimens only. For serum specimens, order SLEG / Legionella pneumophila (Legionnaires Disease), Antibody, Serum.
Other specimen types (eg, plasma or body fluids) that may contain Legionella antigen have not been verified for testing.
Specimen Required
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 0.5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
3. Excessively bloody or very turbid specimens containing protein, cells, or particulates will be canceled. They can inhibit the function of the test.
4. Centrifuging to remove particulates is not approved.
5. Specimens with any dyes or unnatural color are not acceptable and will be canceled.
Specimen Type
UrineSpecimen Minimum Volume
0.25 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 7 days | |
Frozen | 14 days | ||
Ambient | 24 hours |
Day(s) Performed
Monday through Friday
TAT: 3 days
Performing Laboratory
Mayo Clinic Laboratories in RochesterMethod Name
Immunochromatographic Membrane Assay
Method Description
The BINAXNOW Legionella Urinary Antigen Test is an immunochromatographic membrane assay to detect Legionella pneumophila serogroup 1 soluble antigen in human urine. Rabbit anti-L pneumophila serogroup 1 antibody (the patient line) is adsorbed onto nitrocellulose membrane. Goat-anti-rabbit IgG (the control line) is adsorbed onto the same membrane as a second stripe. Rabbit anti-L pneumophila serogroup 1 antibodies are conjugated to visualizing particles that are dried onto an inert fibrous support. The resulting conjugate pad and the striped membrane are combined to construct the test strip. This test strip and a well to hold the swab specimen are mounted on opposite sides of a hinged, book-shaped test device.
To perform the test, a swab is dipped into the urine specimen, removed, and then inserted into the test device. Reagent A is added from a dropper bottle. The device is then closed, bringing the specimen into contact with the test strip. L pneumophila serogroup 1 urinary antigen captured by immobilized anti-L pneumophila serogroup 1 antibody reacts to bind conjugated antibody. Immobilized goat-anti-rabbit IgG also captures visualizing conjugate, forming the control line. A positive test result is visually read in 15 minutes or less depending on the concentration of antigen present in the urine specimen. A negative result, read in 15 minutes, indicates that L pneumophila serogroup 1 antigen was not detected in the urine specimen.
The test is interpreted by the presence or absence of visually detectable pink-to-purple colored lines. A positive result will include the detection of both a patient and a control line, while a negative assay will produce only the control line. Failure of the control line to appear, whether the patient line is present or not, indicates an invalid assay.(Package insert: BinaxNOW Legionella Urinary Antigen Card. Abbott Diagnostics; IN852050 Rev.12, 01/2021)
Reference Values
Negative
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
87899
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
LAGU | Legionella Ag, U | 32781-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
81268 | Legionella Ag, U | 32781-7 |
Report Available
1 to 2 daysReject Due To
Gross hemolysis | Reject |
Turbid Dyes/unnaturally colored | Reject |
Forms
If not ordering electronically, complete, print, and send 1 of the following with the specimen:
-Infectious Disease Serology Test Request (T916)
-Microbiology Test Request (T244)
Aliases: Legionella pneumophila; Legionellosis; Legionnaires' Disease; LEGION U