A Recombinant Antigen-Based Enzyme Immunoassay Using Recombinant ROP2 (ELISA-Rrop2) for the Diagnosis of Congenital Toxoplasmosis
- 1. Department of Pediatrics and Pediatric Surgery, State University of Londrina, Brazil
- 2. Post-graduate Program in Animal Sciences, State University of Londrina, Brazil
- 3. Department of Preventive Veterinary Medicine, State University of Londrina, Brazil
- 4. Department of Pathological Sciences, State University of Londrina, Brazil
- 5. Department of Pathology, State University of Londrina, Brazil
Abstract
The diagnosis of congenital toxoplasmosis is difficult because the majority of infected children have negative results for anti-Toxoplasma gondii IgM. We evaluated an enzyme immunoassay (ELISA) with the recombinant ROP2 antigen (ELISA-rROP2) of T. gondii for detecting IgG antibodies. The tachyzoite RH strain was used for DNA extraction and incorporation into an Escherichia coli (E. coli) vector for rROP2 protein expression. Polystyrene microplates were sensitized with the rROP2 protein, and serum samples from 27 children with suspected congenital toxoplasmosis were tested. Nine (33.3%) children had a confirmed diagnosis of congenital toxoplasmosis, and in 18 cases (66.7%), the condition was ruled out. The test showed a sensitivity of 44.4% [95% confidence interval (CI) 13.7 - 78.8], a specificity of 55.6% (95% CI 30.8 - 78.5), a positive predictive value of 33.3% (95% CI 10.0 - 65.1), and a negative predictive value of 66.7% (95% CI 38.4 - 88.2). Conclusion: Further studies should be performed with ELISA-rROP2 method for the detection of anti-T. gondii IgG for diagnosis of congenital toxoplasmosis.