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Lab Dept:


Test Name:


General Information

Lab Order Codes:



Toxoplasma Antibody, IgM only, serum; Toxoplasma Antibody, IgM, Serum; T. gondii; Toxoplasma gondii; Toxoplasmosis

CPT Codes:

86778 – Antibody; Toxoplasma, IgM

Test Includes:

Toxoplasma IgM antibody level reported in IU/mL.


Test Indications:

Serological tests specific for Toxoplasma gondii IgM antibodies are useful aids in the diagnosis of both congenital and acute acquired toxoplasmosis.

Infection of the normal adult is commonly asymptomatic. In cases with clinical manifestations, the most common symptom is lymphadenopathy, which may be accompanied by an array of other symptoms making differential diagnosis difficult.

Transplacental transmission of the parasite resulting in congenital toxoplasmosis can occur during the acute phase of acquired maternal infection.

Lab Testing Sections:

Serology - Sendouts

Referred to:

Mayo Medical Laboratories (Test: TOXMP)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

1 - 3 days, test set up Monday - Saturday

Special Instructions:

Indicate if ocular toxoplasmosis is suspected. Specimens that have been heat-treated should not be used.


Specimen Type:



Red top tube

Draw Volume:

1.5 mL (Minimum: 0.6 mL) blood

Processed Volume:

0.5 mL (Minimum: 0.2 mL) serum


Routine blood collection

Specimen Processing:

Lab Staff: Centrifuge specimen, remove serum aliquot into a screw-capped round bottom plastic vial. Store and ship at refrigerated temperatures. Forward promptly.

Patient Preparation:


Sample Rejection:

Specimens that have been heat-treated or have obvious microbial contamination should not be used; mislabeled or unlabeled specimens; gross hemolysis; gross lipemia


Reference Range:

Reference Value (IU/mL):


<0.55 IU/mL


≥0.55 – <0.65 IU/mL


≥0.65 IU/mL


Critical Values:



Negative results do not preclude recent primary Toxoplasma gondii infection. A negative result could indicate either no previous exposure or could also be seen in cases of remote exposure with subsequent loss of detectable antibody. A second specimen collected at a later point in time may be needed to rule out a recent infection.

Positive serologic results alone are not diagnostic of Toxoplasma gondii infection. For example, infections with Epstein-Barr virus (EBV) have been suspected to elicit antigen-specific IgM responses (e.g., false positive IgM toxoplasma reactions) in individual previously sensitized to a variety of non-EBV infectious agents.

Since persisting IgM levels may be detected long after the onset of acquired infection, the use of a single serological test result must be used with caution in those cases when it is critical to establish the time of infection. This applies to the diagnosis of acute Toxoplasma gondii infection acquired during pregnancy. Determination of the date of infection based solely on the results of detectable IgM antibody to Toxoplasma gondii is not recommended. That determination should include clinical history and previous serology, since low levels of IgM antibody may persist for a year or more. The use of a test to determine a rise in IgG antibody to Toxoplasma gondii may provide additional information as to the date of infection. Therefore, the FDA has instructed commercial suppliers of toxoplasma IgM kits to recommend toxoplasma IgG testing also be performed.


Enzyme-Linked Fluorescence Assay (ELFA)


Mayo Medical Laboratories June 2013


9/14/2004: This test has been changed at MML from a qualitative to a quantitative test. Please note that reference ranges have been changed to numeric values to aid in the level of antibody level.

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