Toxoplasma gondii Antibodies, IgG and IgM
Ordering Recommendation
First-line test for identifying visceral T. gondii infection. CDC suggests equivocal or positive results should be retested using a different assay from another reference laboratory specializing in toxoplasmosis testing (IgG dye test, IgM ELISA, reflex to avidity and/or other tests).
New York DOH Approval Status
Specimen Required
Serum Separator Tube (SST).
Allow specimen to clot completely at room temperature. Separate from cells ASAP or within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens.
Refrigerated.
Plasma or urine. Contaminated, heat-inactivated or grossly hemolyzed specimens.
Label specimens plainly as "acute" or "convalescent."
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Methodology
Semi-Quantitative Chemiluminescent Immunoassay
Performed
Sun-Sat
Reported
Within 24 hours
Reference Interval
Test Number |
Components |
Reference Interval |
---|---|---|
Toxoplasma gondii Ab, IgM | 7.9 AU/mL or less |
Interpretive Data
Component | Interpretation |
---|---|
Toxoplasma gondii Antibody, IgG | 7.1 IU/mL or less: Not Detected. 7.2-8.7 IU/mL: Indeterminate - Repeat testing in 10-14 days may be helpful. 8.8 IU/mL or greater: Detected. |
Toxoplasma gondii Antibody, IgM | 7.9 AU/mL or less: Not Detected. 8.0-9.9 AU/mL: Indeterminate - Repeat testing in 10-14 days may be helpful. 10.0 AU/mL or greater: Detected - Significant level of Toxoplasma gondii IgM antibody detected and may indicate a current or recent infection. However, low levels of IgM antibodies may occasionally persist for more than 12 months post-infection. |
FDA
Note
This test should not be used for blood donor screening, associated re-entry protocols, or for screening Human Cell, Tissues and Cellular and Tissue-Based Products (HCT/P).
Hotline History
CPT Codes
86777; 86778
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0050557 | Toxoplasma gondii Ab, IgM | 8040-8 |
0050770 | Toxoplasma gondii Ab, IgG | 8039-0 |
Aliases
- Torch
- Torch IgG
- Torch IgM
- Toxoplasma gondii Ab, IgG
- Toxoplasma gondii Ab, IgM