Search

Cystic hydatid disease (Hydatidosis) is the most serious tape-worm infection prevalent in the cattle and sheep raising area of the world. Hydatidosis in man (as an accidental host) is caused by infection with the ova containing larval stage of Echinococcus granulosus. In the last decade, different techniques have been employed for sero-diagnosis of hydatidosis; as IHA, IFA, ELISA, CCLE (Counter Current Immuno-electrophoresis). This paper evaluated the validity of ELISA and IHA. Since whole hydatid cyst fluid was used as a source of antigen for serodiagnosis. Thirty surgical and pathological hydatidosis proven patients were examined. The sensitivity and specificity of ELISA were 96.7% & 97.5% respectively, and that of IHA were 86.7%, &95% respectively.

Experimental duel infection with S. mansoni and E. granulosus was induced in mice to determine their effect on serum nitric oxide (NO) level and accordingly on the sequences of histopathological lesions affecting the liver. The results showed that serum NO level was significantly increased (p<0.05) in mice infected with both parasites (GI) in comparison to either S. mansoni (GIV) or E. granulosus (GV). The NO elevation on hepatic pathological lesions of both diseases showed a marked reduction of granuloma size with absence of concentric fibrosis in GI as early as 4 weeks of concomitant infection as compared to GIV. In spite of the significant increase of NO level when E. granulosus infection induced in late stages of schistosomisais (GsII & III), yet granuloma size was not suppressed. Also, there was absence or death of hydatid cyst in mice (GI) compared to E. granulosus (GV). So, the duel infection with the two parasites affected serum NO level and hepatic histopathology, by ameliorative or deteriorative effects, according to duration of infection with either.

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.

ELISA-hydatid cyst fluid antigen (HCF-Ag-ELISA) and conventional echinococcosis IHAT were assessed for cystic hydatid disease (CHD), confirmed by HCF-Ag immunoblotting assay. The sensitivity of the tests was 94.4% and 83.3% for HCF-Ag-ELISA and IHA respectively. HCF-Ag-ELISA showed some cross-reaction in tumor cases (5.5%), but no cross-reaction was observed in Rheumatoid arthritis patients. IHA showed 100% specificity. To confirm this data SDS-PAGE immunoblotting using HCF-Ag was applied. Echinococcus specific reactions were reported with 44Kda, 34Kda, 29Kda and 8Kda HCF-Ag resolved bands. Cross-reaction was found with 27Kda, 21Kda, 16Kda and 13Kda bands in tumor patients. Moreover, cross-reaction was found with 200Kda, 175Kda, 62Kda, 52Kda and 40Kda in serological anti-Schistosoma antibodies positive cases. So, using specific HCF-Ag components, immunoblotting provided 100% sensitivity and specificity in CHD.

Soluble adhesion molecules namely soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sELAM-1) were assayed in hydatid patients with or without complications. It was found that sICAM-1 was significantly increased in patients with hydatid cysts as compared to the control group. In lymphoedemic filariasis cases both sICAM-1 and sELAM-1 showed highly significant increase more than the control group. However, non of both soluble adhesion molecules were significantly elevated in patients with ascariasis, hymenolepiasis, heterophyiasis and strongyloidiasis as compared to controls. The results indicated that SICAM-1 & S ELAM-1 are useful markers for hydatidosis and filariasis, but not for ascariasis, hymenolepiasis, heterophyiasis and strongyloidiasis

Tissue inhibitor of metalloproteinases-1 (TIMP-1), in the serum levels of 27 patients was significantly higher and almost a double of that measured in healthy patients. Considerably higher TIMP-1 levels were recovered in patients with higher specific antibody titers and those with hepatic cysts in relation to low-titer patients and pulmonary cysts respectively, reflecting an immunologic dose-dependent and cell type-specific regulation of TIMP-1 production. Yet, these higher TIMP-1 levels stop short to be statistically significant in both groups. Patients with multi-sited hydatid cysts also show statistically insignificant higher TIMP-1 levels compared to single-sited cysts.

Five groups of Swiss albino mice (Mus Musculus albinus) were intraperitoneally inoculated with 2,000 aseptic normal (control group) and gamma irradiated E. granulosus, larvae at different dose levels of 40 Kr, 60 Kr, 80 Kr and 100 Kr, respectively. Haematological studies showed a marked leucocytosis, a progressive increase in the average percentage of eosinophils as well as a great successive decrease in haemoglobin concentration through out the time of infection in control group as compared to the treated ones. Meanwhile the leucocytic count and the Haemoglobin concentration in treated mice was dose dependent as well as time dependent whereas the eosinophil percentage was only dose dependent rather than time dependent.