Identification of Parastrongylus cantonensis antigens for use in immunodiagnosis

Abstract

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SOS-PAGE) and immunoblot analysis revealed that the somatic extracts of Parastrongylus cantonensis were highly heterogeneous, with at least 4 and 25 components of the larval and adult worm antigens respectively being immunogenic. Sera from two patients with parasitologically confirmed parastrongyliasis, 8 patients with presumptive parastrongyliasis, 12 patients with various other parasitic infections and two healthy adults were analysed for their reactivities against the somatic extracts of P. cantonensis third-stage larvae and adult worms. Extensive cross-reaction of P. cantonensis antigens with the sera from patients with other parasitic infections was observed. However, a 31 kDa component present in the larval and adult worm antigens of P cantonensis reacted with the sera of all the parasitologically proven patients and 4 out of the 8 presumptive patients, but not with those of other parasitic infection or healthy individuals. This 31 kDa P. cantonensis antigen is a potential candidate for the specific immunodiagnosis of human parastrongyliasis.