TOXO IgG
Enzyme ImmunoAssay (ELISA) for the quantitative/qualitative determination of IgG antibodies to Toxoplasma gondii in plasma and sera.
Toxoplasma gondii is an obligate intracellular protozoan parasite that is probably capable of infecting all species of mammals, including man. The detection of IgM antibodies to T.gondii is particularly helpful for the diagnosis of acute infections in “risk” individuals, in association with AIDS, organ transplantation and pregnancy. As most of T.gondii infections are mild or asymptomatic in otherwise healthy individuals, the detection of T.gondii specific IgM antibodies, in absence of detectable specific IgG, has become important for the monitoring of acute infections in pregnant women, as the parasite can lead to severe birth defects. Moreover, as T.gondii infections are most severe in immunocompromised patients, where the disease can be fatal, acute infections due to this parasite have to be distinguished from other disorders.
Recently developed IgM capture assays provide the clinician with a helpful and reliable test, not affected by the rheumatoid factor as it happens to be in classic sandwich tests.
Microplates are coated with native T. gondii antigens, highly purified by sucrose gradient centrifugation and inactivated.
The solid phase is first treated with the diluted sample and IgG to T. gondii are captured, if present, by the antigens.
After washing out all the other components of the sample, in the 2nd incubation bound anti Toxoplasma gondii IgG are detected by the addition of polyclonal specific anti human IgG antibodies, labelled with peroxidase (HRP).
The enzyme captured on the solid phase, acting on the substrate/chromogen mixture, generates an optical signal that is proportional to the amount of anti Toxoplasma gondii IgG antibodies present in the sample. A Calibration Curve, calibrated against the W.H.O 3nd international standard , makes possible a quantitative determination of the IgG antibody in the patient.
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