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Toxoplasma gondii Antibody, IgG
MessageSendout, Mayo test code :TXPG
Test Code
LAB501
Alias/See Also
T. gondii Toxoplasma gondii Toxoplasmosis Toxoplasma IgG TXPG
CPT Codes
86777
Preferred Specimen
0.6 mL serum from a gold serum gel tube
Minimum Volume
0.6 mL
Other Acceptable Specimens
Red tube
Instructions
Centrifuge and aliquot serum into a plastic vial.
Transport Container
Plastic vial
Transport Temperature
Refrigerated
Specimen Stability
Refrigerated (preferred): 21 days
Ambient: 72 hours
Frozen: 90 days
Ambient: 72 hours
Frozen: 90 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis: Reject
Gross lipemia: Reject
Gross icterus: Reject
Additives (eg, biocides, antioxidants): Reject
Gross lipemia: Reject
Gross icterus: Reject
Additives (eg, biocides, antioxidants): Reject
Methodology
Electrochemiluminescence Immunoassay (ECLIA)
FDA Status
Approved
Setup Schedule
Monday through Saturday
Report Available
1-3 days
Limitations
Diagnosis of recent or active infection by Toxoplasma gondii can only be established based on a combination of clinical and serological data. The result of a single serum sample does not constitute sufficient proof for diagnosis of recent infection.
A suspected diagnosis of central nervous system or congenital toxoplasmosis should be confirmed by detection of Toxoplasma gondii DNA by polymerase chain reaction (PCR) analysis of cerebrospinal fluid or amniotic fluid specimens, respectively (PTOX / Toxoplasma gondii, Molecular Detection, PCR, Varies).
To differentiate between a recently acquired and past infection in patients who are IgM and IgG positive for Toxoplasma antibodies, Toxoplasma IgG avidity testing should be considered. A high avidity index for IgG antibodies indicates that the infection occurred at least 4 months ago. No clinical interpretation can be deduced from a low avidity result.
A negative Toxoplasma IgM result in combination with a positive IgG result does not completely rule out the possibility of an acute infection with Toxoplasma.
The detection of Toxoplasma-specific IgG antibodies in a single specimen indicates a previous exposure to T. gondii but is not sufficient to distinguish between an acute or latent infection (irrespective of the level of the IgG antibody titer).
Individuals may not exhibit any detectable IgG antibodies at the early stage of acute infection.
Elevated anti-IgM or IgG titers may be absent in patients who are immunocompromised. Results should be interpreted with caution in patients who are either HIV-positive, receiving immunosuppressive therapy, or have other disorders leading to immunosuppression.
The performance of the assay has not been established for cord blood testing. Specimens from neonates, pretransplant patients or body fluids other than serum and plasma, such as urine, saliva or amniotic fluid have not been tested.
Specimens should not be collected from patients receiving therapy with high biotin doses (ie, > 5 mg/day) until at least 8 hours following the last biotin administration.
A suspected diagnosis of central nervous system or congenital toxoplasmosis should be confirmed by detection of Toxoplasma gondii DNA by polymerase chain reaction (PCR) analysis of cerebrospinal fluid or amniotic fluid specimens, respectively (PTOX / Toxoplasma gondii, Molecular Detection, PCR, Varies).
To differentiate between a recently acquired and past infection in patients who are IgM and IgG positive for Toxoplasma antibodies, Toxoplasma IgG avidity testing should be considered. A high avidity index for IgG antibodies indicates that the infection occurred at least 4 months ago. No clinical interpretation can be deduced from a low avidity result.
A negative Toxoplasma IgM result in combination with a positive IgG result does not completely rule out the possibility of an acute infection with Toxoplasma.
The detection of Toxoplasma-specific IgG antibodies in a single specimen indicates a previous exposure to T. gondii but is not sufficient to distinguish between an acute or latent infection (irrespective of the level of the IgG antibody titer).
Individuals may not exhibit any detectable IgG antibodies at the early stage of acute infection.
Elevated anti-IgM or IgG titers may be absent in patients who are immunocompromised. Results should be interpreted with caution in patients who are either HIV-positive, receiving immunosuppressive therapy, or have other disorders leading to immunosuppression.
The performance of the assay has not been established for cord blood testing. Specimens from neonates, pretransplant patients or body fluids other than serum and plasma, such as urine, saliva or amniotic fluid have not been tested.
Specimens should not be collected from patients receiving therapy with high biotin doses (ie, > 5 mg/day) until at least 8 hours following the last biotin administration.
Reference Range
Included with report
Clinical Significance
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.
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, Rochester, Minnesota
Additional Information
Toxoplasma gondii Antibody, IgG, Serum
