Relationship between circulating antigen level and morbidity in Schistosoma mansoni-infected children evaluated by ultrasonography.

Hassan, Mohamed A.; Hegab, Mohamed H. A.; Soliman, Samy Z.; Gaber, Osama; Shalaby, Mohsen M.; Kamel, Faten Mohammed Mahmoud

doi:10.4269/ajtmh.1999.61.635

Cited by 14 publications

(13 citation statements)

References 13 publications

(17 reference statements)

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“…The process was demonstrated in vitro: live S. mansoni eggs and soluble egg antigens induce collagen synthesis in cultured human fibroblasts (Boros 1983). There is in fact a correlation between levels of circulating egg antigens and Symmers' fibrosis in S. mansoni-infected children (Hassan et al 1999). In conclusion, more attention should be paid to endothelial injury caused by the parasite eggs before the granulomatous stage.…”

Section: Discussionmentioning

confidence: 97%

Experimental schistosomiasis, protective aspects of granulomatous reaction in the mouse liver

et al. 2005

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We show two mechanisms of liver protection by the granulomatous reaction against Schistosoma mansoni eggs entrapped in the organ. First, eosinophil peroxidase and its substrate H(2)O(2) are released by inflammatory cells in the immediate vicinity of the parasite eggs. The efficiency of this process was demonstrated by administration of antioxidants to infected mice. The treatment, which reduces H(2)O(2) production, significantly improved the ability of parasite eggs to hatch after collection from the liver. Secondly, we labeled the released egg antigens in liver histological sections and we found that the lattice of collagen fibers which is built around eggs appears to create a barrier preventing released compounds from diffusing freely in surrounding tissues. Together, oxidative processes and antigen containment allow the parasitized liver to cope with the dual threat posed by parasite eggs, i.e. a highly resistant chitinous eggshell and the release of toxic substances.

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Section: Discussionmentioning

confidence: 97%

Experimental schistosomiasis, protective aspects of granulomatous reaction in the mouse liver

et al. 2005

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“…ELISA based detection of circulating antigens, CAA or CCA in serum or urine has been shown to be highly sensitive and specific in the diagnosis of active schistosomiasis (Deelder et al, 1989;Van Lieshout et al, 1992;De Clercq et al, 1997). Moreover, these circulating antigens have been correlated with the intensity of infection and morbidity of the disease (Van Lieshout et al, 1992;Polman et al, 1995;Hassan et al, 1999). Because of less field applicability of the ELISA-based method for the diagnosis of schistosomiasis at a community level, reagent strip/dipstick based assay has INTRODUCTION D iagnosis of intestinal schistosomiasis by demonstrating the parasites' eggs in feces using convectional techniques like Kato and formol-ether concentration has been claimed for its low sensitivity in case of low intensity of infection, post-treatment situations as well as for egg output fluctuation (De Vlas & Gryseels, 1992;Gryseels & De Vlas, 1996;Engels et al, 1996;Kongs et al, 2001).…”

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confidence: 99%

Field-based evaluation of a reagent strip test for diagnosis of Schistosomiasis mansoni by detecting circulating cathodic antigen (CCA) in urine in low endemic area in Ethiopia

Legesse

Erko

2008

Parasite

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Summary :The sensitivity, specificity, positive and negative predictive values of a reagent strip test for the diagnosis of schistosomiasis mansoni by detecting circulating cathodic antigen (CCA) in urine were evaluated using 184 stool and urine samples collected from schoolchildren living in relatively low endemic area of schistosomiasis mansoni in Ethiopia. A combined result of stool samples processed by Kato and formol-ether concentration methods was used as gold standard. The results showed that detection of CCA in urine using reagent strip test was slightly higher than the combined results of the stool techniques (65.2 % vs 42.4 %, p > 0.05) in suggesting the prevalence of the disease. The sensitivity, specificity, positive and negative predictive values of the reagent strip test were 76.9 %, 43.4 %, 50 % and 71.9 %, respectively. The result of egg counts using Kato method suggested that detection of urine CCA could be used to indicate the intensity of infection. Nevertheless, like that of stool examination, the reagent strip test was found to be less sensitive in case of light to moderate infections. About 23.1 % of the study children who were excreting the eggs of the parasite were found negative by the reagent strip test. The relative insensitivity of a reagent strip test in low intensity of infection necessitates for the development of more sensitive assay that can truly discriminate schistosome-infected from non-infected individuals. Résumé : ÉVALUATION SUR LE TERRAIN D'UN KIT DE DÉTECTION DANS LES URINES DES ANTIGÈNES CIRCULANTS CATHODIQUES POUR

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“…Further, at high SEA concentrations (200 µg/ ml), hemolysis also becomes a factor. Circulating antigens of approximately 0.1-3 µg/ml of SEA have been measured in serum and urine samples from schistosome-infected individuals [43,44] and are directly correlated with egg counts. However, the local concentrations of SEA in the tissues and capillaries around the deposited eggs are thought to be far higher than circulating levels and are likely more relevant to evoking host responses.…”

Section: Discussionmentioning

confidence: 99%

<i>Schistosoma mansoni</i> Soluble Egg Antigens Trigger Erythrocyte Cell Death

Kasinathan¹,

Greenberg²

2010

Cell Physiol Biochem

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Estimated to affect nearly 300 million people worldwide, schistosomiasis is caused by parasitic flatworms of the genus Schistosoma. The major pathological consequences of chronic schistosomiasis are associated with soluble egg antigens (SEA) secreted from schistosome egg deposits in liver and other organs. The vigorous immune responses induced by egg antigens result in granuloma formation and other pathophysiological symptoms such as hepatosplenomegaly and anemia. Risk of anemia correlates with infection intensity and the level of host hemoglobin is inversely proportional to egg count. Schistosomiasis-associated anemia could be multifactorial, but the potential link and molecular underpinnings are unclear. Here, we evaluate whether S. mansoni SEA affects survival of mouse erythrocytes. Erythrocytes incubated with different concentrations of SEA were tested for various markers of erythrocyte cell death. Erythrocytes exposed to SEA exhibit elevated intracellular Ca²⁺ levels as measured by Fluo-3 AM fluorescence in flow cytometry, and they also display concentration-dependent, Ca²⁺-dependent, and heat-sensitive increases in phosphatidyl serine exposure. Further, SEA-exposed erythrocytes show increased fluorescence using the in situ apoptosis marker CaspACE FITC, indicating the involvement of caspase-mediated cell deformation. Taken together, these results offer several lines of experimental evidence for SEA-induced erythrocyte cell death and may provide new insights into factors contributing to schistosomiasis-associated anemia.

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Relationship between circulating antigen level and morbidity in Schistosoma mansoni-infected children evaluated by ultrasonography.

Cited by 14 publications

References 13 publications

Experimental schistosomiasis, protective aspects of granulomatous reaction in the mouse liver

Experimental schistosomiasis, protective aspects of granulomatous reaction in the mouse liver

Field-based evaluation of a reagent strip test for diagnosis of Schistosomiasis mansoni by detecting circulating cathodic antigen (CCA) in urine in low endemic area in Ethiopia

<i>Schistosoma mansoni</i> Soluble Egg Antigens Trigger Erythrocyte Cell Death

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