Antigenic components in the
crude extracts of Spirometra mansoni plerocercoid were analyzed in early experimental
infections and in
IgG subclass observed in clinical
sparganosis. By
IgG immunoblot, sera obtained serially from experimental mice, fed 5 spargana each, were reacted with the
crude extracts.
Protein bands at 36-26 kDa and 103 kDa showed positive reactions since two weeks after
infection. In a differential immunoblot, in which a monospecific antibody against sparganum
chymase at 36 kDa was pre-treated, the reactions at 36-26 kDa disappeared, indicating that the sparganum
chymase and its degradation products invoked
IgG antibody reactions. When 69 patients sera of human
sparganosis were examined for their
IgG subclass responses,
IgG4 levels showed the highest reaction which was followed by
IgG1. The
IgG4 antibody also reacted mainly with 36-31 kDa
protease. These results indicate that 36 kDa
chymase of S. mansoni plerocercoid is the main antigenic component inducing
IgG antibody response in early stage of experimental
sparganosis and for specific
IgG subclass reactions in human
sparganosis.