TOXOCARA IGG ANTIBODY BY ELISA

Code
000.0000
Name
TOXOCARA IGG ANTIBODY BY ELISA
Category
None
Department
Send-Out
Start Date
Expiration Date
Synonyms
CPT Codes
86682
Site
SBMF
Reference Test
44361
ATLAS Test Code

Specimen Information

Type

Gold, SST

Volume

1.0 ml

Transport Info

Centrifuge and immediately transfer serum to separate plastic tube
Refrigerated

Fasting Required?
False
Patient Instructions

Reference Range

0.299 OD or less: Negative - No significant level of Toxocara IgG antibody detected.
0.300-0.500 OD: Equivocal - Questionable presence of Toxocara IgG antibody detected. Repeat testing in 10-14 days may be helpful.
0.501 OD or greater: Positive - Presence of IgG antibody to Toxocara detected, suggestive of current or past infection.

Methodology

Enzyme-Linked Immunosorbent Assay (ELISA)

Clinical Significance

Assay will detect the presence of serum IgG antibodies specific for the T. canis excretory antigen, aiding in the diagnosis of Toxocariasis.

Toxocariasis is an infection caused by migration of the roundworm Toxocara larvae to organs and tissues. Although the genus Toxocara includes many species, only T. canis (roundworm of the fox and dog) has been consistently implicated in the disease. Toxocara larva migrans has historically been under reported, but it is now believed to be the second most common helminthic infection in developed countries. The disease is acquired by ingestion of soil contaminated with embryonated eggs of Toxocara. After they have been ingested, embryonated eggs hatch into larvae, travel across the gut wall, and migrate to the liver or lungs through lymphatic and circulatory systems. Larvae then spread from the lungs to several organs, causing damage by their migration and induction of granulomatous lesions. The disease manifests itself in two distinct forms: visceral larval migrans (VLM) and ocular larval migrans (OLM). Signs and symptoms of VLM vary from an asymptomatic state with mild eosinophilia to a severe and potentially fatal disorder, including hepatomegaly, hypergammaglobulinemia, pulmonary symptoms, fever, pneumonitis, or neurological disorders, with symptoms persisting for a year or more. Patients with OLM also vary widely in presentation, from asymptomatic states to acute lesions in the eye caused by penetration of the larvae into the eyes, with vision loss in the affected eye. This assay will detect the presence of serum IgG antibodies specific for the T. canis excretory antigen, aiding in the diagnosis of Toxocariasis. The diagnosis of VLM is usually made clinically by observation of eosinophilia or leukocytosis, accompanied by hepatomegaly or other organ involvement. Clinical diagnosis may be hampered by an inability to distinguish between Toxocara and other parasitic infections. Balyisascaris procyonis, Fasciola hepatica, and Ascaris lumbricoides can also cause VLM, so infections with similar organisms cannot be ruled out. The ELISA assay appears specific and is useful for confirming a clinical suspicion of LVM. However, Toxocara antibody titers in populations without clinical symptoms of LVM vary dramatically, and elevated titers alone cannot definitively establish the diagnosis. This assay should be used to aid in the diagnosis and confirmation of patients in whom there is a clinical suspicion of T. canis infection. Results for this test should not be used without correlation to clinical history or other data. Because antibody response varies depending on worm burden and location, a negative result does not necessarily rule out Toxocariasis infection.

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