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HelpTest Code LAB501 Toxoplasma gondii Antibody, IgG, Serum
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Reporting Name
Toxoplasma Ab, IgG, SSpecimen 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.
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
| Heat-inactivated specimen | Reject |
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 14 days | |
| Frozen | 14 days |
Specimen Minimum Volume
0.4 mL
Day(s) Performed
Monday through Saturday
Specimen Retention Time
14 daysReport Available
Same day/1 to 3 daysReference 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.
Useful 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.
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 |
Supportive Data
To evaluate the accuracy of the BioPlex Toxoplasma IgG multiplex flow immunoassay, 600 prospective serum samples submitted for routine Toxoplasma IgG testing by the VIDAS enzyme-linked fluorescence immunoassay (ELFA; bioMerieux) were also analyzed in a blinded fashion by the BioPlex assay within a 24-hour period. Samples with discordant results after initial testing were repeated by both assays during the same freeze/thaw cycle. Further resolution of discrepant results was performed by sending the samples to the Palo Alto Medical Foundation for testing. The results are summarized below:
Table. Comparison between BioPlex and VIDAS Toxoplasma IgG Assays
|
|
Toxoplasma IgG (VIDAS ELFA) |
|||
|
BioPlex Toxoplasma IgG |
|
Positive |
Negative |
Equivocal |
|
Positive |
63 |
2(a) |
6 |
|
|
Negative |
0 |
528 |
0 |
|
|
Equivocal |
0 |
0 |
1 |
|
a: Both serum samples were negative by the Sabin-Feldman dye test at the Palo Alto Medical Foundation Toxoplasma laboratory.
Sensitivity: 100% (63/63); 95% CI: 93.1% to 100%
Specificity: 99.6% (528/530); 95% CI: 98.5% to 99.9%
Overall Percent Agreement: 98.7% (592/600); 95% CI: 97.3% to 99.4%
Forms
If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.