Role of fast-ELISA and western blot in diagnosis of human fascioliasis using crude adult worm and excretory/secretory fasciola antigens

Human fascioliasis is becoming one of the public health problems in Egypt. Because of the similarity of fascioliasis manifestations and other hepatobiiary diseases, the clinical diagnosis of this disease is usually difficult. Diagnosis of human fascioliasis using different worm antigens [crude worm antigen [CW] and excretory/secretory antigen [EIS]] and different methods [Falcon assay screening test enzyme linked immunosorbent assay [FAST-ELISA] and immnoelectrotransfer blot [Western Blot]]. The second objective is to compare between FAST-ELISA and Western Blot using the same antigen, also to compare between the use of [CW] antigen and [E/S] antigen in each method aiming to evaluate the immunodiagnostic potential of both techniques and both antigens. The third objective is to detect the most specific and sensitive immunoreactive bands in both CW and E/S Fasciola antigens by western blot technique. One hundred and fifteen individuals [40 with chronic fascioliasis, 15 with suspected acute fascioliasis, 40 infected with other parasites and 20 apparently healthy] were included in this study. Sera, urine samples and repeated stool samples were collected from all cases. The stool samples were examined for presence of different parasites and Fasciola eggs were counted by Kato-Katz technique. Fasciola [CW] and [E/S] antigens were prepared. Sera were tested by [FAST-ELISA] and [Western Blot] techniques using [CW] and [E/S] antigens. FAST-ELISA using [E/S] gave better results than that using CW antigen, as the recorded sensitivities and specificities were 97.5% and 98.3% with E/S antigen and 92.5% and 86.7% with crude antigen respectively. By using each of CW antigen and E/S antigen, Western blot was more sensitive and specific than FAST-ELISA in diagnosis of human fascioliasis. After fractionation of both antigens by electrophoresis and immunoblotting, it was found that 27 KDa of Fasciola E/S antigen was the best fraction [100% sensitive and specific]. Immnoelectrotransfer blot [western blot] is more sensitive and specific than FAST-ELISA. In immnoelectrotransfer blot, 27 KDa of E/S antigen was the most specific, sensitive and accurate band that could detect Fasciola antibodies in all Fasciola infected patients

Immunohistochemical demonstration of toxoplasma antigen in the placenta of cases of abortion

The sera of 65 women presenting with abortion and 30 women with normal obstetric history were examined for Toxoplasma antibodies using IHAT. The level of Toxoplasma antibodies was significantly higher in cases of abortion than in normal control. Sixteen formalin fixed paraffin- embedded placenta [representing negative and positive cases for toxoplasmosis] were examined by immunoperoxidase procedure to detect Toxoplasma antigen in tissues. They were also examined histopathologically [by HX and E.]. Toxoplasma antigen could be detected in the placenta of all cases with high titer. In all sero- negative cases, Toxoplasma antigen could not be detected. Out of six cases with low or moderate titer, one case only showed Toxoplasma antigen in the placenta. The histopathological studies of seropositive cases revealed a picture of villitis in the form of slight villous oedema with scattered mononuclear cellular infiltration mainly of lymphocytes and plasma cells. The data proved the usefulness of immunoperoxidase procedure as a specific and sensitive test to confirm the diagnosis of serologically positive toxoplasmosis in high titer

Comparative study between enzyme-linked immunosorbent assay and circumoval precipitin test using schistosoma mansoni and haematobium eggs in diagnosis of schistosoma mansoni

Sera from male patients of different age groups with simple and complicated S. Mansoni infection were examined for the presence of antischistosomal antibodies using the circumoval precipitin test [COPT] and enzyme linked immunosorbent assay [ELISA] tests. Both viable S. Mansoni and S. haematobium eggs were used as antigens for COPT. In ELISA test S. mansoni soluble egg antigen [SmSEA] and S. haematobium SEA [ShSEA] were also used. The results showed that SmSEA gave higher sensitivity than ShSEA in the ELISA. COPT was more sensitive with viable S. Mansoni eggs than on using viable S. haematobium eggs. ELISA test was found to be significantly more sensitive than COPT. The O.D. readings in ELISA test were higher by using SmSEA than those by ShSEA. The specificity obtained was 100% in ELISA test and COPT using viable S. mansoni eggs, whereas COPT done by viable S. haematobium eggs was 90% specific. The sensitivity of ELISA [using SmSEA] and COPT using either of the two antigens was directly increased with the egg output. At the same time the sensitivity of ELISA increased with the development of complications while the COPT sensitivity decreased with the development of complications. Higher sensitivity was obtained with ELISA test using SmSEA with increase of age whereas COPT sensitivity decreased with increasing age. These results suggested that ELISA test using SmSEA was the best in diagnosis of mansoniasis