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Test Code Billings Clinic: 8210 Mayo: TOXGP Toxoplasma gondii Antibody, IgG, Serum

Reporting Name

Toxoplasma Ab, IgG, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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.

Method Name

Multiplex Flow Immunoassay (MFI)


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 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 Type

Serum

Specimen Minimum Volume

0.4 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject
Heat-inactivated specimen Reject

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.

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.

Day(s) Performed

Monday through Saturday

Report Available

Same day/1 to 3 days

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

Forms

If not ordering electronically, complete, print, and send Infectious Disease Serology Test Request (T916) with the specimen.