| Test Name: |
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Legionella Ab
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| Test Code(s): |
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MISC / RMISC
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| CPT Code(s): |
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86713
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| Methodology: |
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Indirect Fluorescent Antibody
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| Clinical Significance: |
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Used to support a diagnosis of Legionnaires disease retrospectively during the convalescent phase of illness.
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| Testing Site: |
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Testing will be sent to an approved reference laboratory.
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| Days Performed: |
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Once a week.
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| Turnaround Time: |
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Routine: 2 - 7 days.
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Specimen Requirements
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| Specimen: |
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Blood
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| Collection Instructions: |
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Acute and convalescent serum required. Collect acute serum during first week of illness and convalescent serum 3-6 weeks post onset for diagnostic testing.
Include date of onset of illness and whether specimen is acute or convalescent.
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| Collection Container: |
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Preferred: Red top
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| Collection Volume: |
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Preferred: 9 mL
Pediatrics: 3 mL
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| Sample Analyzed: |
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Serum
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| Volume Required: |
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Preferred: 1 mL
Pediatrics: 0.5 mL
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| Specimen Processing: |
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Centrifuge. Transfer cell free serum to plastic vial. Refrigerate.
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| Specimen Transport: |
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Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.
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Interpretation
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Reference Interval:
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A titer equal to 1:128 on a single serum or an increase of less than four-fold in the titer between acute and convalescent sera is considered negative.
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| Test Limitations: |
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The only confirmed positive serology result is demonstration of a four-fold rise in titer greater than or equal to 1:128 between paired sera. Varying background levels of antibody in the general population make it difficult to support a diagnosis based on a single serum titer.
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| Additional Information: |
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Must include date of collection and date of onset of illness.
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