Test Code Billings Clinic: 8083 Mayo: QFP Q Fever IgM and IgG, Titer, Serum
Reporting Name
Q Fever IgM/IgG, Titer, SPerforming Laboratory
Mayo Clinic Laboratories in RochesterUseful For
Diagnosis of Coxiella burnetii, the causative agent of Q fever
Method Name
Only orderable as a reflex. For more information see QFEVR / Q Fever Antibody Screen with Titer Reflex, Serum.
Indirect Immunofluorescence
Ordering Guidance
Specimen Required
Only orderable as a reflex. For more information see QFEVR / Q Fever Antibody Screen with Titer Reflex, Serum.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Type
SerumSpecimen Minimum Volume
0.25 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 7 days | |
Frozen | 7 days |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Reference Values
Only orderable as a reflex. For more information see QFEVR / Q Fever Antibody Screen with Titer Reflex, Serum.
Q fever phase I antibody, IgG
<1:16
Q fever phase II antibody, IgG
<1:16
Q fever phase I antibody, IgM
<1:16
Q fever phase II antibody, IgM
<1:16
Reference values apply to all ages.
Interpretation
A negative result argues against Coxiella burnetii infection. If early acute Q fever infection is suspected, collect a second specimen 2 to 3 weeks later and retest.
A negative result following a reactive C burnetii enzyme immunoassay screen suggests a falsely reactive screen. In cases of suspected acute C burnetii infection, repeat testing in 2 to 3 weeks is recommended.
Phase I antibody titers greater than or equal to phase II antibody titers are consistent with chronic infection or convalescent phase Q fever.
Phase II antibody titers greater than or equal to phase I antibody titers are consistent with acute/active infection.
In Q fever sera, it is common to see IgG titers of 1:128 or greater to both phase I and phase II antibody titers. IgG class antibody titers appear very early in the disease, reaching maximum phase II titers by week 8 and persisting at elevated titers for longer than a year. Phase I titers follow the same pattern, although at much lower levels, and may not be initially detected until convalescence.
In Q fever sera, it is common to see IgM titers of 1:64 or greater.
IgM class antibody titers appear very early in the disease, reaching maximum phase II titers by week 3 and declining to very low levels by week 14. Phase I titers follow the same pattern, although at much lower levels, and may not be initially detected until convalescence.
Day(s) Performed
Monday through Saturday
Report Available
Same day/1 to 3 daysTest 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
86638 x 4
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
QFP | Q Fever IgM/IgG, Titer, S | 77175-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
80965 | Q Fever Phase I Ab, IgG | 34716-1 |
24011 | Q Fever Phase II Ab, IgG | In Process |
81115 | Q Fever Phase I Ab, IgM | 9710-5 |
24009 | Q Fever Phase II Ab, IgM | 9711-3 |
24010 | Interpretation | 69048-7 |
Testing Algorithm
For more information see Infective Endocarditis: Diagnostic Testing for Identification of Microbiological Etiology.