Effect of interferon-alpha on experimental Schistosoma mansoni infection in mice.

To investigate the immunomodulatory effect of the Th1 mediated cytokine IFN-alpha on schistosomiasis, this cytokine was weekly injected into mice experimentally infected with S. mansoni, beginning from day 0 (group II), week 3 (group III), week 6 (group IV) and week 10 (group V) post-infection. TGF-beta1 serum levels were estimated on a weekly basis and beginning one week after initiation of IFN-alpha therapy, while all animals were sacrified on week 14 to be used for egg counts in liver and small intestine, oogram study for determination of the maturity of deposited eggs, and histopathological examination of stained liver sections. IFN-alpha treated groups were characterized by a more intense oviposition in the intestine (liver/intestine ratio less than 1), with higher egg numbers the earlier IFN-alpha was administered. Oograms of the intestine indicated the level of immature eggs to be statistically significantly higher in group II, III and IV than in the control group I (p < 0.05). In IFN-alpha medicated mice, the mean numbers and diameters of hepatic granulomas were less than in GI, in addition to a lower representation of fibrocellular and fibrous granulomas among them (all parameters p < 0.05), especially in Gs IV & V. The inflammatory cell population in the form of eosinophils, histiocytes and giant cells was more pronounced in Gs III, IV & V. TGF-beta1 serum levels showed a progressive rise, however more pronounced in the untreated control. A statistically positive significant was established between TGF-beta1 levels and number, size and percentage of fibrotic hepatic granulomas in all groups.

Early post-treatment immunoglobulin profile in human schistosomiasis.

In a trial at determining the most relevant immunoglobulin isotype that could reflect success of praziquantel treatment, an ELISA using soluble egg antigen (SEA) was applied on sera of Egyptian patients suffering from active intestinal schistosemiasis without hepatic complications, determining the levels of IgE, IgA, IgM, IgG1, IgG2, IgG3 and IgG4 raised against the SEA, both, pre- and early post-treatment. The positive results obtained to all anti-SEA immunoglobulin isotypes before treatment support the usefulness of this technique in the diagnosis of schistosomiasis. Except for IgG3 subclass, a statistically significant correlation was found between egg output-reflecting intensity of infection- and the different immunoglobulin levels, especially anti-SEA IgG4. When repeating the assay 5-6 months after treatment, the immunoglobulin levels showed either a rise (in case of IgE) or a drop (in case of IgA, IgM & IgG1-4), all of statistical significance, yet, IgG1-4 were still positive. So, ELISA could not give a definite indication of cure after anti-bilharzial treatment. IgE, IgG2 and IgG4 were revealed to be the most significant immunoglobulin isotypes at the post-treatment level, both statistically and due to their implications on resistance/ susceptibility to re-infection and also due to the correlation of IgG4 with the tendency to develop periportal fibrosis. Conclusively, although not having defined a particular Ig isotype as marker for cure, yet it exposed the urge for early post-treatment determination of IgE and IgG4 isotypes, which could serve as markers for picking up high risk patients susceptible to reinfection or liable to develop bilharzial periportal fibrosis, and who might benefit from a second course of specific treatment.

Cerebrospinal echinococcosis: serodiagnosis using different hydatid cyst fluid antigens.

Cerebrospinal hydatid disease diagnosis may impose some problems, as ultrasonography is not applicable and serology may not detect the low antibody titre often associated with intracranial or orbital cystic echinococcosis. Serological tests were performed on 14 cases with intracranial or spinal cystic lesions, out of which 9 were cases of hydatidosis, in addition to 26 cases with other parasitic diseases as detected by stool examination. The sensitivity of all tests and antigens used did not exceed 6 out of the 9 positive cases, and achieved by the Eg1 and Eg2 when applied in the ELISA. The specificity of this technique using the two antigens was 92.3%& 76.9%, respectively. Semi-purified Em1 and purified 44 KDa used in the ELISA, crude Eg1 used for the CIEP and the crude commercial antigen of the IHAT, all gave lower sensitivities than the former two antigens, yet their specificities amounted to 100%. In conclusion, for diagnosis of cerebrospinal hydatidosis the home-prepared Eg1 antigen is recommended in the ELISA system, as it is relatively easily prepared from available resources to be supplemented with radio-imaging techniques especially Magnetic Resonance Imaging and/or MR spectroscopy, the latter being very helpful in clearly differentiating various types of intracranial cysts.