Evaluation of Recombinant SAG1 Protein for Detection of Toxoplasma gondii Specific Immunoglobulin M by ELISA Test

Toxoplasmosis is a serious disease in immunocompromised patients and pregnant women. Differentiation of acute and chronic infection is a major challenge in serodiagnosis of the disease. Since the aim of this study was to assess the diagnostic utility of recombinant SAG1 (rec-SAG1) for the detection of Toxoplasma-specific IgM antibodies in human sera, by an enzyme-linked immunosorbent assay (ELISA). The purified recombinant protein SAG1 was applied in house ELISA test and the ability of it in binding to specific immunoglobulin M in 30 serum samples of acute infected patients was evaluated. The results obtained by assays with the recombinant SAG1 and standard commercial assays were compared. The sensitivity and specificity of in house ELISA compared to a standard commercial ELISA (com-ELISA) were 80% and 90%, respectively. It was concluded that the rec-SAG1 could be an alternative marker for detection of anti Toxoplasma-specific IgM and diagnosis of acute infection.