Toxoplasma gondii (IgG), ELISA, CSF

Test Code

10666

CPT Codes
86777

Preferred Specimen

0.5 mL CSF

Minimum Volume

0.25 mL

Transport Container

Sterile screw-cap vial

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 7 days
Refrigerated: 14 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Lipemia • Body fluids other than CSF • Icteric • Bacterial contamination

Methodology
ELISA

Setup Schedule

Tues, Fri

Report Available

2-6 days

Reference Range

<0.90

Interpretive Criteria

<0.90	Antibody not detected
0.90-1.09	Equivocal
≥1.10	Antibody detected

Diagnosis of central nervous system infections can be accomplished by demonstrating the presence of intrathecally-produced specific antibody. Interpreting results may be complicated by low antibody levels found in CSF, passive transfer of antibody from blood, and contamination via bloody taps.

Clinical Significance

This test detects IgG against Toxoplasma gondii in the cerebrospinal fluid (CSF). This panel may be useful as part of a diagnostic evaluation for central nervous system (CNS) toxoplasmosis, especially in immunocompromised individuals [1]. The results of this test must be interpreted in conjunction with CSF-serum antibody ratios.

Toxoplasmosis is a parasitic infection caused by the protozoan T gondii. Immunocompetent individuals generally have no symptoms or flu-like symptoms that resolve within weeks or months. Immunocompromised individuals can have severe or even fatal toxoplasmosis, which most often involves the CNS [1].

Serologic testing is commonly used in diagnosing toxoplasmosis. However, immunocompromised patients can have low or undetectable serum levels of Toxoplasma-specific IgG antibodies. For immunocompromised patients with suspected CNS infection, testing CSF may provide evidence of CNS toxoplasmosis through direct observation of T gondii, detection of T gondii DNA (eg, by polymerase chain reaction), or demonstration of local production of Toxoplasma-specific antibodies [1].

The results of this test should be interpreted in the context of pertinent clinical history and physical examination findings.

Reference
1. McAuley JB, et al. Toxoplasma. In: Carroll KC, et al, eds. Manual of Clinical Microbiology. 12th ed. ASM Press; 2019. https://www.clinmicronow.org/doi/book/10.1128/9781683670438.MCM.ch141

Performing Laboratory

Quest Diagnostics Nichols Institute-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.