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

Experimental schistosomiasis: the effect of chemotherapy on concomitant immunity and resistance to reinfection

To study the effect of chemotherapy on concomitant immunity, mice infected with Schistosoma mansoni were treated after either 8 or 16 weeks of primary infection and challenged at different periods after treatment. Results were compared to infected untreated groups of mice. It was found that in mice treated 8 weeks after infection the degree of protection decreased gradually with time and 16 weeks after treatment no significant degree of protection was obtained. On the other hand, mice infected for 16 weeks prior to treatment showed higher degrees of protection and there was still significant degree of resistance to challenge infection after 16 weeks of treatment. It was concluded that in schistosomiasis mansoni there is a certain degree of resistance to reinfection after successful treatment of primary infection prior to treatment

Detection of toxoplasma antigen in the tonsils among cases of chronic tonsillitis using immunoperoxidase technique

Sera of 80 cases of chronic tonsillitis and 30 normal controls were examined for Toxoplasma antibodies by the indirect immunofluorescent antibody titer were found to be higher in patients than in the control group. An indirect immunoperoxidase technique was applied to all cases of tonsillitis [seropositive and seronegative] to detect Toxoplasma antigen in the tissues. They were also examined histopathologically [by Hx. and E]. Toxoplasma antigen was detected in 69% of seropositive cases and in only 2% of seronegative cases. All cases with antibody titer of 1/128 or more showed Toxoplasma antigen in their tissues. The histopathological picture of tonsils of positive cases of toxoplasmosis showed the characteristic features of toxoplasmic lymphadenitis. The results of this work showed the usefulness of immunoperoxidase technique as a valuable and reliable test to confirm the diagnosis of serologically and histologically suspicious cases of toxoplasmic lymphadenitis

Immunodiffusion, countercurrent immunoelectrophoresis and elisa for detection of circulating schistosomal antigens and antibodies

Circulating schistosomal antigens and antibodies were determined in 34 patients and 26 control using ouchterlony immunodiffusion [I.D.], double countercurrent immunoelectrophoresis [D.C.I.E.] and ELISA methods. The adult S. mansoni antigen was used for detection of antibodies, and rabbit antischistosomal [S. mansoni] adult antiserum was used for detection of schistosomal antigens. The results showed that ELISA technique was the most sensitive, but no difference in the specificity of the three methods. It was concluded that ELISA technique had the highest diagnostic efficacy for detection of both circulating antibodies and antigens when compared to D.C.I.E. and I.D