Performance of quantum dot nanobeads-based immunoassay in diagnosis of toxoplasmosis

Background: Diagnosis of toxoplasmosis relies mainly on determination of IgG and IgM using ELISA.However, inter-laboratory evaluation of performance of many commercial kits gave unsatisfactoryagreements. Merging the innovative use of quantum dots nanobeads (QDNBs) immunoassay may yieldhigher sensitivity and specificity than the conventional used methods.Objective: The present study aims to evaluate the performance of QDNBs based immunoassay inserodiagnosis of human toxoplasmosis.Subjects and Methods: The study included 175 subjects divided into three categories; 122 patientswith clinical manifestations suggestive of toxoplasmosis; 32 patients proved positive for other parasiticinfections, and 21 healthy control subjects. In comparison to Sabin Feldman dye test (SFDT), as a goldstandard test, serum samples were examined in an immunoassay utilizing QDNBs for detection of T. gondiispecific IgG and IgM antibodies.Results: Compared to SFDT, combined QDNBs-IgG/IgM immunoassay exhibited sensitivity of 95.4%,specificity of 98.9%, positive predictive value (PPV) of 98.8%, and negative predictive value (NPV) of95.6%, with relative agreement, validity, and accuracy of almost 97%.Conclusion: It was concluded that QDNBs-based immunoassay improves the performance of ELISAparticularly sensitivity as well as shorten the assay time.