Schistosoma japonicum recombinant ferritin: expression and it's immunodiagnostic potential for evaluation of chemotherapeutic efficacy.

In order to analyse the immunodiagnostic potential and evaluation of chemotherapeutic efficacy with S. japonicum recombinant ferritin(rSjferritin). S. japonicum ferritin was expressed in E. coli strain ER2566 and purified with HisBind Resin. Immunoreactivity of rSjferritin was analysed by western blot. rSjferritin was used to detect specific IgG in sera of patients before treatment and at 6 months,1 year and 2 years after treatment, and also to detect cross reactive IgG antibody in sera of patients with other parasitic diseases and healthy individuals by ELISA. The results showed that purified rSjferritin was only recognized by schistosomeinfected sera and immunized rabbits sera. The sensitivity and specificity of rSjferritin as coating antigen was as good as those of AWA and SEA. The negative reversion rate of specific IgG in the sera of patients at 6 months, 1 year and 2 years was 31.8%, 63.3% and 90.5% respectively. The level of IgG against rSjferritin significantly decreased after treatment, and at 2 years after treatment, the IgG returned to normal level. rSjferritin could be used to diagnose schistosomiasis japonica and evaluate the therapeutic efficacy of the disease.