Effect of early treatment with praziquantel on serum connective tissue metabolite markers in children and adolescents with intestinal schistosomiasis mansoni.

This work was designed to assess the reflection of early treatment by praziquantel (CAS 55268-74-1, EMBAY 8440, Biltricide) on serum connective tissue metabolite markers (hyaluronic acid and procollagen III peptide) in patients with active intestinal schistosomiasis. Children and adolescent subjects from primary and secondary schools in an endemic area of schistosomiasis mansoni were included. Age-matched subjects from an urban area served as normal controls. All subjects were examined clinically and parasitologically. Detection of hepatitis B seromarkers was also done. The infected subjects were treated with praziquantel at a dose of 60 mg/kg of body weight which was repeated after 4 weeks. Serum hyaluronic acid and procollagen III peptide were measured by radioimmunoassay. High hyaluronic acid was encountered in infected subjects when compared to their respective age-matched controls. Significant decrease of 4 and 8 weeks post-treatment was noted when compared to ist level before treatment. There was no significant change in serum procollagen III peptide on comparing infected subjects to their controls, whereas a significant increase was observed in its level after 4 and 8 weeks post-treatment compared to that before treatment. This work suggests that early treatment of intestinal schistosomiasis with specific chemotherapy (praziquantel) decreases serum hyaluronic acid and increases procollagen III peptide probably via downregulation of granulomatous inflammatory cell reaction and activation of collagenase enzymes, respectively.

Detection of circulating schistosome antigens in serum and urine of schistosomiasis patients and assessment of cure by a monoclonal antibody.

From a panel of monoclonal antibodies (MAb), an IgM monoclonal antibody (7F1/6B) reactive with repetitive epitopes on S. mansoni soluble egg antigen was selected. This MAb was employed both as antigen capture and detection antibody in a sandwich ELISA and had a detection limit < 1 ng S. mansoni SEA/mi. Serum and urine samples were collected from rural students who had S. mansoni (169 subjects) or mixed S. mansoni and S. haematobium (64 subjects) infections. Samples were collected before and at 4, 8 and 12 weeks after praziquantel therapy. Circulating schistosome antigens (CSA) were demonstrated in 90% of sera and 97% of urine samples of S. mansoni group and in 91% of sera and 100% of urine samples of mixed infection group. All sera from 29 uninfected individuals, 30 patients with other parasites and 70% of 55 S. haematobium-infected subjects were negative in this assay. CSA level in serum and urine samples correlated positively with the number of S. mansoni eggs/g stool in both groups. A significant reduction in CSA level was observed in serum and urine samples after praziquantel therapy. By 12 weeks post-treatment, negativity was 98% in sera and 97% in urine of S. mansoni-infected group and 98% in sera and 91% in urine of mixed infection group. The data demonstrate that the use of MAb 7F1/6B for the detection of CSA provides a sensitive method for immunodiagnosis of schistosomiasis and monitoring of cure.

Evaluation of specific Fasciola antigen in the immunodiagnosis of human fascioliasis in Egypt.

Enzyme-linked immunosorbent assay (ELISA) and enzyme linked immunoelectrotransfer blot technique (EITB) were employed for the detection of circulating Fasciola antibodies in infected human sera using a specific Fasciola antigen, prepared by immunoaffinity purification of homogenates of Fasciola hepatica adult worms. Ninety two individuals diagnosed clinically and parasitologically were classified into: Fascioliasis group (21 patients), schistosomiasis group (21 patients) and subjects harbouring other parasitic infections (50 patients). Eighteen healthy individuals served as normal controls. ELISA was 100% sensitive and 93% specific with 96.5% diagnostic efficacy, whereas EITB was 100% sensitive and specific with 100% diagnostic efficacy. Our data revealed that ELISA can be used as a good screening test while EITB can serve as a confirmatory test for immunodiagnosis of fascioliasis.

Purification and characterization of a specific Fasciola antigen.

Specific Fasciola antigen was prepared from homogenates of Fasciola hepatica adult worms. The homogenate was ultracentrifuged and the supernatant containing crude Fasciola antigen was then passed over a cyanogen bromide activated sepharose 4B column coupled with antiserum against Schistosoma mansoni adult worm surface antigen. The specific, Schistosoma-free Fasciola antigen was tested for its specificity by immunodiffusion. Characterization of the specific Fasciola antigen was done by gradient poly-acrylamide gel electrophoresis and immunoblotting technique. The electrophoresis migration pattern of specific Fasciola antigen, stained with Coomassie blue, showed 7 bands in the 12-54 kDa regions. Using the immunoblotting technique, a batch of positive fascioliasis sera recognized two specific bands at the 33 and 54 kDa regions.