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HelpTest Code TXPG Toxoplasma gondii Antibody, IgG, Serum
Ordering Guidance
IgG antibodies in patients younger than 6 months of age are typically the result of passive transfer from the mother. To assess possible Toxoplasma gondii infection in patients younger than 6 months, order TXPM / Toxoplasma gondii Antibody, IgM, Serum.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.6 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial
Useful For
Quantitative detection of IgG antibodies to Toxoplasma gondii.
This test is not useful for diagnosing infection in infants younger than 6 months of age. In that age group, IgG antibodies usually are the result of passive transfer from the mother.
Method Name
Electrochemiluminescence Immunoassay (ECLIA)
Reporting Name
Toxoplasma Ab, IgG, SSpecimen Type
SerumSpecimen Minimum Volume
0.6 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 21 days |
| Frozen | 90 days | |
| Ambient | 72 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
| Additives (eg, biocides, antioxidants) | Reject |
Reference Values
Negative
<1 IU/mL Negative
≥1-<3 IU/mL Borderline
≥3 IU/mL Positive
Reference values apply to all ages.
Interpretation
Negative:
Toxoplasma gondii IgG not detected. False negative results may occur in immunocompromised patients or if testing performed within 1-2 weeks of initial exposure and repeat testing may be helpful. A single negative result should not be used to rule-out toxoplasmosis, and repeat testing is recommended for patients at high risk for infection.
Borderline
Repeat testing on a new sample collected in 2-3 weeks is recommended to assess for seroconversion. Borderline Toxoplasma IgG results may be due to very low levels of circulating IgG during the acute stage of infection. Seroconversion from negative to positive IgG is indicative of T gondii infection after the first negative specimen.
Positive
Toxoplasma gondii IgG antibodies detected, indicating recent or past infection. A significant change in T. gondii IgG levels suggests recent infection. For confirmation of toxoplasmosis, the US Food and Drug Administration issued a Public Health Advisory (07/25/1997) that recommends sera found to be positive for Toxoplasma gondii IgM antibodies should be sent to a Toxoplasma reference laboratory.
Day(s) Performed
Monday through Saturday
Report Available
Same day/1 to 3 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test 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
86777
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TXPG | Toxoplasma Ab, IgG, S | 8039-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| GTXP | Toxoplasma Ab, IgG, S | 40677-7 |
| DEX04 | Toxoplasma IgG Value | 8039-0 |