Related Experiment Video
Updated: Jul 29, 2026
High Yield Purification of Plasmodium falciparum Merozoites For Use in Opsonizing Antibody Assays
Published on: July 17, 2014
Development of monoclonal antibodies against Sj29 and its possible application for schistosomiasis diagnosis
Cui-Ping Ren1, Quan Liu2, Feng-Chun Liu2
1Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology, Anhui Provincial Laboratory of Zoonoses, Laboratory of Tropical and Parasitic Diseases Control, School of Basic Medical Sciences, Anhui Medical University, Hefei, China; Department of Immunology, Anhui Medical University, Hefei, China.
Objective:
Timely Schistosoma japonicum detection improves outcomes in schistosomiasis. Here, we established a double antibody sandwich ELISA to detect Schistosoma japonicum.
Methods:
Sj29 polyclonal and monoclonal antibodies were developed and identified. A Sj29 double antibody sandwich ELISA was evaluated.
Results:
Assay sensitivity for detecting Schistosoma japonicum circulating antigen Sj29 was 76.7% (23/30), 54.5% (18/33) and 50.0% (18/36) in patients with acute, chronic and advanced schistosomiasis. No false positives or cross-reactivity was observed in healthy controls or patients with clonorchiasis, paragonimiasis, or ancylostomiasis, respectively. By contrast, false positives (5.7%) and cross-reactivity (6.5%-10%) were detected using an AWA-ELISA. The circulating antigen positive rates decreased significantly faster than that of the antibody detection after 6 months treatment (22.2%, 4/18 and 88.9%, 16/18). Chi-Square Tests revealed that Sj29 sandwich ELISA had lower sensitivity than AWA indirect ELISA in the detection of S. japonicum infected patients (p<0.05). Although our assay detection specificity in patients infected with other parasites or healthy controls appeared higher, the difference between the assays was insignificant. However, our assay showed significantly better results in monitoring praziquantel therapeutic effects (p=0.001), with antigen-positive rates decreasing significantly faster than antibody detection rates after 6 months of treatment (22.2%, 4/18 versus 88.9%, 16/18).
Conclusions:
Sj29 double antibody sandwich ELISA was established. The specificity of this method for detecting healthy sera was 100%. Meanwhile, Sj29 sandwich ELISA may have a potential diagnostic capability to distinguish current from past infections and assess drug treatment responses.
