Abstract: AIM:To elucidate the effect of praziquantel treatment on immunopathology in host
in- fected with Schistosoma japonicum.METHOD:Employing immunohistochemical technique and profile
analytical technique,the authors observed the changes of antigen (soluble egg antigen,SEA) and
antibody level as well as granuloma in the liver of mice infected with Schistosoma japonicum
following praziquantel treatment.RESULTS:It was found that the number of adultworms in the
treated group was reduced by98.3per centas compared to the control group , the mean weight and volume of livers were all lesssened (P < 0. 05) at the 5th week after treatment. In cured mice, there was a significant decrease in number of egg nodules located on liver surface; the ova in the liver tissue were all calcified and some egg nodular foci became scar tissue. It was noted that the SEA level in liver tissue of the treated group decreased or even disappeared, but the antibody level showed no change; the average diameter and area of egg granuloma were significantly reduced (P < 0. 01). CONCLUSION: Praziquantel treatment could lower the SEA level in the liver tissue, and thereby inhibit the egg granuloma formation, but it could not alter the antibody level, likewise, could not reverse the egg granulomatous changes already formed

Key words: Schistosoma japonicum, praziquantel treatment, immunopathology