Ascaris suum larval excretory-secretory (AsES)
antigen and larval (AsLA) as well as adult somatic
antigen (AsAA) which were thought to be possibly helpful in the diagnosis of
visceral larva migrans (VLM) due to A. suum
infection were investigated in the present study. Serum taken from mice orally inoculated with approximately 250 embryonated eggs of A. suum or Toxocara canis, or 40 third-stage larvae of Angiostrongylus cantonensis were assessed by
enzyme-linked
immunosorbent assay (ELISA) using the AsES
antigen, AsLA or AsAA at 1, 2, 3, 4, 6 and 8 weeks post
infection (WPI). The titer of serum
IgG from mice infected with A. suum increased from 1 WPI and a peak at 4 WPI was observed when it reached approximately three times the level of uninfected control mice. Thereafter, it decreased gradually but remained high as found from 6 to 8 WPI. No cross-reactions of heterologous serum
IgG against AsES
antigen was observed, whereas heterologous serum
IgM exhibited significant cross-reactions to AsES
antigen. Cross-reactivities to AsLA and AsAA by heterologous serum
IgG as well as
IgM antibodies were also observed in the trial. Altogether, the AsES
antigen apparently seemed to be superior to the other two somatic
antigens when used in the diagnosis of A. suum-induced VLM with serum
IgG as tested by ELISA. Moreover, it was the first report to test the possibly antigenic cross-reactivity between A. suum and A. cantonensis.