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HelpTest Code TOXGP Toxoplasma gondii Antibody, IgG, Serum
Reporting Name
Toxoplasma Ab, IgG, SUseful For
Determining whether a patient has had previous exposure to or recent infection with 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.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumOrdering 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 TXM / Toxoplasma gondii Antibody, IgM, Serum.
Specimen Required
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 Minimum Volume
0.4 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days |
Reference Values
Toxoplasma ANTIBODY, IgG
Negative
Toxoplasma IgG
≤9 IU/mL (Negative)
10-11 IU/mL (Equivocal)
≥12 IU/mL (Positive)
Reference values apply to all ages.
Day(s) Performed
Monday through Saturday
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 |
|---|---|---|
| TOXGP | Toxoplasma Ab, IgG, S | 88746-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TOXG | Toxoplasma Ab, IgG, S | 40677-7 |
| DEXG6 | Toxoplasma IgG Value | 8039-0 |
Interpretation
A positive Toxoplasma IgG result is indicative of current or past infection with Toxoplasma gondii. A single positive Toxoplasma IgG result should not be used to diagnose recent infection.
Equivocal Toxoplasma IgG results may be due to very low levels of circulating IgG during the acute stage of infection. A second specimen should be submitted for testing if clinically indicated.
Individuals with negative Toxoplasma IgG results are presumed to not have had previous exposure to T gondii. However, negative results may be seen in cases of remote exposure with subsequent loss of detectable antibody.
Seroconversion from negative to positive IgG is indicative of T gondii infection subsequent to the first negative specimen.
Recent or acute infection with T gondii can be evaluated with TXM / Toxoplasma gondii Antibody, IgM, Serum. A suspected diagnosis of acute toxoplasmosis should be confirmed by detection of T gondii DNA by polymerase chain reaction (PCR) analysis of cerebrospinal fluid or amniotic fluid specimens (PTOX / Toxoplasma gondii, Molecular Detection, PCR, Varies).
For additional confirmation of a diagnosis, the US Food and Drug Administration issued a Public Health Advisory (07/25/1997) suggesting that sera found to be positive/equivocal for T gondii IgM antibody be sent to a Toxoplasma reference laboratory.
Clinical Reference
1. Tenter AM, Heckeroth AR, Weiss LM: Toxoplasma gondii: from animals to humans. Int J Parasitol. 2000 Nov;30(12-13):1217-1258
2. Jones JL, Kruszon-Moran D, Sanders-Lewis K, Wilson M: Toxoplasma gondii infection in the United States, 1999-2004, decline from the prior decade. Am J Trop Med Hyg. 2007 Sep;77(3):405-410
3. Luft BJ, Remington JS: Toxoplasmic encephalitis in AIDS. Clin Infect Dis. 1992 Aug;15(2):211-222
4. Wong SY, Remington JS: Toxoplasmosis in pregnancy. Clin Infect Dis. 1994 Jun;18(6):853-861
5. Wang ZD, Liu HH, Ma ZX, et al: Toxoplasma gondii infection in immunocompromised patients: A systematic review and meta-analysis. Front Microbiol. 2017 Mar 9;8:389
Report Available
Same day/1 to 3 daysMethod Name
Multiplex Flow Immunoassay (MFI)
Forms
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.