Coxiella burnetii (Q-Fever) Antibodies, IgG and IgM, Phase I and II with Reflex to Titer

Casandra

Casandra Test Code AR58617Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2012634CPT Code 86638

Coxiella burnetii (Q-Fever) Antibodies, IgG and IgM, Phase I and II with Reflex to Titer

Also known as: Q-F GM

Clinical Use

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Use

This test is used to confirm the presence of the infectious agent Coxiella burnetii (Q-fever) in symptomatic patients. Detection of IgG and IgM antibodies to phase I and phase II antigens assists in diagnosing both acute and chronic Q fever infections. Acute infection typically shows a four-fold rise in phase II IgG titers, and chronic infection is indicated by a phase I titer greater than the phase II. Additional serological testing may be required to confirm diagnosis, and the phase II IgM titers can aid in diagnosing early conversion in acute cases.

Special Instructions

Parallel testing of acute and convalescent specimens is preferred, with convalescent specimens needing to be received within 30 days from the receipt of acute specimens. Specimens should be marked as 'acute' or 'convalescent' as applicable. Additional charges apply if any Phase I or Phase II screening result is Indeterminate or Positive, necessitating titer(s).

Limitations

Limitations of the test include the potential for persistent elevation of IgG and IgM titers for months or years following acute infection or during convalescence. A single phase II IgM positive result on an acute sample may indicate early conversion or a false positive, requiring testing of a convalescent serum for confirmation. In chronic Q fever, absence of phase I IgG titer limits diagnostic value of phase I IgM titer.

Test Details

New York Approved