Recent advances in serodiagnosis for cysticercosis

Neurocysticercosis (NCC) caused by infection with the larval stage of Taenia solium is an important cause of neurological disease worldwide. Up to the present, many studies on characterizing species-specific antigens of T. solium have been done and several high quality antigens for serodiagnosis are available. Hence the research on serodiagnosis has been shifted to the next phase, stable production of diagnostic antigens using molecular techniques. In order to establish an enzyme-linked immunosorbent assay (ELISA) using recombinant proteins, we carried out molecular cloning and identified four diagnostic antigen candidates (Ag1, Ag1V1, Ag2, and Ag2V1). Recombinant proteins, except Ag2V1, were successfully expressed using an Escherichia coli expression system. Immunoblot analysis using NCC patient sera detected recombinant proteins. But as reactivity to rAg1 was too weak, Ag1 was not suitable for the immunodiagnosis antigen. Therefore Ag1V1 and Ag2 were chosen for ELISA antigens and Ag1V1/Ag2 chimeric protein was expressed. Of 49 serum samples from NCC patients confirmed to be seropositive by immunoblot analysis, 44 (89.7%) were positive by ELISA. Serum samples from patients with other parasitic infections did not recognized Ag1V1/Ag2 chimeric protein. Ag1V1/Ag2 chimeric protein obtained in this study is of value for differential immunodiagnosis.