Production of monoclonal antibodies against target schistosomal antigen secreted in the urine of Schistosoma mansoni-infected patients.

This study was undertaken to develop an immunodiagnostic test of active human schistosomiasis mansoni using a monoclonal antibody which targets urinary schistosomal antigen. Polyclonal antisera raised in rabbits against the processed urine of Schistosoma mansoni-infected patients showed very high and significant reactivity with ES product of ova compared with other different S. mansoni antigens. The monoclonal antibody (4.23) was reactive with repetitive epitopes of S. mansoni soluble egg antigen and ES product of ova with molecular mass range of 65-23 kDa and 80-23 kDa, respectively. It recognised different stages of the parasite life-cycle, with no cross reaction with Fasciola or hydatid antigen. MAbs were characterised by isotyping, immunoelectrophoresis, SDS-PAGE and the enzyme-linked immunoelectrotransfer blot technique, ELISA, and their recognition of carbohydrate or protein antigenic epitopes by periodate oxidation and trichloroacetic acid treatment of the antigen. It was used for detection of circulating schistosomal antigen in an antigen capture antibody sandwich ELISA on sera and urines of 58 S. mansoni-infected patients, 17 S. haematobium-infected patients, 15 parasite-free negative healthy controls and sera from 13 schistosomiasis-free patients harbouring Fasciola or hydatid infections. The percentage sensitivity of the assay in the serum of S. mansoni-infected patients was 98.4% and in urine 94.8%. A positive correlation was found between the number of faecal S. mansoni eggs and the circulating antigen, both in serum and in urine. Antigen circulating in urine correlated with that in the sera of S. mansoni patients. These data provide a sensitive and non-invasive method almost comparable with the use of sera for immunodiagnosis of schistosomiasis and an indirect way to reflect the intensity of infection.

Studies on certain serum enzymatic activities in hepatosplenic bilharziasis.

Determination of serum enzymatic activities in hepatosplenic bilharziasis (H.S.B.) were conducted in 100 bilharzial patients, in different stages and 30 controls SGot, SGPT, ALK pH, ALD and SLDH with its both fractions heat stable and labile.). Early elevation of serum enzymatic activities of SGOT, SGPT and SALK. pH, may be considered as a sensitive parameter for functional changes in H.S.B. rather than other conventional liver function tests. The elevated enzymic activity of total LDH in this study was associated with elevation in its both fractions. In particular, the changes in the total activity was in parallel with that of its heat labile fraction. The latter may be considered as a confirmatory test for marked deterioration of liver functions in H.S.B. The changes in the heat stable fraction was inconstant and may be attributed to extrahepatic bilharzial dissimilation. Significantly high serum enzymatic activity of SALD was found in cases of H.S.B. particularly those showing striking muscle wasting.