To eliminate
schistosomiasis, appropriate diagnostic tests are required to monitor its prevalence and transmission, especially in the settings with low endemicity resulting from the consecutive
mass drug administration.
Antibodies that react with either crude soluble schistosome egg
antigens or soluble worm
antigen preparations have been used to monitor
infection in low-prevalence regions. However, these detection methods cannot discriminate current and past
infections and are cross-reactive with other parasites because both
antigens contain numerous
proteins and
glycans from schistosomes, and standard preparations need maintenance of the life cycle of the schistosome. To evaluate the potential utility of nine recombinant Schistosoma mansoni
proteins as single defined
antigens for serological diagnosis, we monitored the kinetics of
antibodies to each
antigen during S. mansoni
infection in mice before and after the treatment with
praziquantel. C57BL/6 mice were infected with 50 cercariae. The levels of
immunoglobulin G (
IgG) raised against five recombinant
antigens (RP26, sm31,
sm32, GST, and LAP1) significantly increased as early
as 2-4 weeks after
infection and rapidly declined by 2 weeks after the treatment, whereas those raised against crude S. mansoni egg
antigens or other
antigens remained elevated long after the treatment. The
IgG1 raised against RP26, sm31, and
serpin decreased after the treatment with
praziquantel, whereas the
IgE raised against
serpin declined strikingly after the treatment. This study clarifies the dynamics of the serological responses to recombinant S. mansoni
proteins during
infection and after the treatment with
praziquantel and identifies several candidate
antigens with potential utility in the monitoring and surveillance of
schistosomiasis toward the elimination of
schistosomiasis.