Legionella pneumophila Antibody (Types 1-6), IgG by IFA
Ordering Recommendation

Provide retrospective evidence of suspected Legionella pneumophila infection.

Semi-Quantitative Indirect Fluorescent Antibody
1-4 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Serum separator tube. 
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.1 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as acute or convalescent. 
Storage/Transport Temperature
Unacceptable Conditions
Contaminated, hemolyzed, or severely lipemic specimens. 
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles) 
Reference Interval
<1:128  Negative -  No significant level of Legionella pneumophila Type 1-6 IgG antibody detected.
1:128 Equivocal - Questionable presence of Legionella pneumophila Type 1-6 IgG antibody detected. Repeat testing in 10-14 days may be helpful.
1:256 or greater Positive -  Presence of Legionella pneumophila Type 1-6 IgG antibody detected, suggestive of current or past infection.
Interpretive Data
Seroconversion between acute and convalescent sera is considered strong evidence of recent infection. The best evidence for infection is a significant change on two appropriately timed specimens where both tests are done in the same laboratory at the same time. This assay may detect infection by any of the serotypes 1-6. The CDC and many state health laboratories recommend testing only for antibody to Legionella pneumophila Type 1. For equivocal or positive IFA results, the CDC protocol suggests follow-up testing for Legionella pneumophila antibody Type 1.

For follow-up testing on equivocal or positive results, refer to Legionella pneumophila Antibody (Type 1), IgG by IFA (0050376).
Hotline History
Component Test Code*Component Chart NameLOINC
0050365Legionella Pneumophila 1-6,IgG21362-9
* 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 view this test within the Laboratory Test Directory found at www.aruplab.com
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