A characteristic immunoblotting pattern for Opisthorchiasis sera with metacercarial antigens.

The protein compositions of homogenized metacercaria and adult Opisthorchis viverrini were characterized by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The two different stages of O. viverrini parasite contained several protein components with very similar mobilities on SDS-PAGE gel. The reaction in immunoblots of sera from patients with opisthorchiasis demonstrated antibodies against heterogeneous protein components of metacercariae and adult O. viverrini parasites. Only the components of metacercariae with molecular weights of 190-200 kD, 132 kD and 107 kD reacted specifically with opisthorchiasis sera. This characteristic reaction pattern was not observed in any control sera of normal subjects or those infected with other parasites. Identical reactions were however also recognized in the sera of experimental infected hamsters with metacercariae, but did not occur with adult worm as the antigen for the immunoblotting reaction. This may indicate that these metacercariae-associated protein components have potential diagnostic value for opisthorchiasis.