[Experimental studies on dynamic changes of circulating antigens of Schistosoma japonicum in infected rabbits].

AIM: To observe the dynamic changes and disappearance of three kinds of schistosome circulating antigens(CAgs) in infected rabbits before and after praziquantel treatment.

METHODS: Dot-ELISA assays were developed by using 3 McAbs to determine the dynamic changes of the gut-associated antigen (GAA), membrane-associated antigen (MAA) and soluble egg antigen (SEA) respectively in sera of rabbits infected with S. japonicum.

RESULTS: By the 4th week after infection 39% of the rabbits infected with S. japonicum were GAA positive and only 8.6% were MAA or SEA positive. All the infected rabbits becOme positive with GAA, MAA and SEA by the 8th week after infection. The titers of the GAA, MAA and SEA in sera of the infected rabbits reached their peaks by the 10th week after infection. Titers from rabbits of the untreated group rabbits remained high level until the 27th week after infection. SEA titers were found negative in 10% of the infected rabbits in the treatment group by the 6th week after treatment. The titers of GAA of, MAA' and SEA were found negative in 20%, 80% and 70% of the rabbits in the treatment group, respectively the 8th after treatment. GAA, MAA and SEA in sera except one of the treated rabbits were all negative by the 14th week after treatment.

CONCLUSION: The determination of GAA is useful for the early diagnosis of schistosomiasis, while the determination of, MAA and SEA might be used for the efficacy evaluation.