Interpretive Data

Toxoplasma, igG

Negative- No detectable antibody.
Equivocal - Presence of detectable antibody cannot be determined.
Positive - Detectable levels of antibody present.

Toxoplasma, IgM 

A positive result for Toxoplasma IgM must be interpreted cautiously, and in the context of clinical findings. Due to a high rate of false positive results with this assay, Clinical Laboratory Standards Institute (CLSI) guidelines recommend confirmatory testing with a different assay at a reference laboratory ( Clinical Laboratory Standards Institute(CLSI).  Clinical Use and Interpretation of Serologic Testing for Toxoplasma gondii, Approved guideline.  (M36-A), Feb 2004).  Therefore, all initial positive results for Toxoplasma-specific IgM will be sent to Palo Alto Toxoplasma Serology Laboratory  for confirmatory Toxoplasma-specific IgM testing.  Results will be reported separately in a scanned report

Notes:

1. In patients infected with Toxoplasma gondii, the IgM antibody appears immediately before, or soon after, the onset of symptoms.

2. The U.S. Food and Drug Administration has advised that no one commercial Toxoplasma IgM test should be used to determine acute infection. If Toxoplasma IgM is positive, confirmation will be performed, at an additional charge. 

3. Levels of IgG antibody to Toxoplasma gondii begin to rise 1 to 2 weeks after infection. Peak levels are reached in 6 to 8 weeks, then gradually decline over months to years. Low titers are generally detectable for life. The antibody titer does not correlate with severity of illness.