Legionella pneumophila Antibody (IgM), IFA

Test Code

Quest Code

CPT Codes

Preferred Specimen
1 mL serum

Minimum Volume
0.2 mL


Transport Temperature
Room temperature

Specimen Stability
Room temperature: 7 days
Refrigerated: 14 days
Frozen: 30 days

Immunofluorescence Assay (IFA)

FDA Status

This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule
Sets up 5 days a week.

Reference Range
<1:256 titer

Clinical Significance
Legionella infection is associated with 2 clinically and epidemiologically distinct illnesses, Legionnaires' disease and Pontiac fever. Legionnaires' disease is characterized by fever, cough, myalgia, and pneumonia, whereas, Pontiac fever is a milder illness without pneumonia. Inhaling aerosols of water contaminated with Legionella species is believed to be the primary mode of infection; the incubation period is generally 2-10 days. The assays performed detect antibodies to Legionella pneumophila serogroups 1-7. An IgM titer >1:256 provides presumptive evidence of infection at an undetermined time. A 4-fold rise in IgG titer to ≥1:256 between acute and convalescent sera may be used in the laboratory confirmation of Legionella infection with these serogroups of L. pneumophila.

Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA
33608 Ortega Highway
San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.