Detection of immunoglobulin G antibodies to Toxoplasma gondii: Evaluation of two commercial immunoassay systems

BackgroundToxoplasmosis is a disease, which can cause severe congenital infection and is normally diagnosed by the detection of Toxoplasma gondii (T gondii)-specific antibodies in the serum of infected patients. Several different tests allow to distinguish recent from past infections and to quantify anti-T gondii-specific IgG, and the results can be used as markers for a chronic or recently seroconverted toxoplasma.MethodsIn the present study, the recent Cobas 6000 Toxo IgG assay (Roche Diagnostics, Indianapolis, IN, USA) for the serological diagnosis of toxoplasmosis was compared with the Axsym Toxo IgG assay (Abbott Laboratories, Diagnostics Division, Abbott Park, IL, USA) employing a panel of negative, low- or high-reactive serum samples that were selected after routine screening in a laboratory of clinical analyses.ResultsThe overall agreement between two methods was 99% (r=0.99, p