ABSTRACT
A total of thirty enzyme-linked immunosorbent [ELISA] assays detecting serum and secretory immunoglobulins against Schistosoma mansoni cercarial antigen preparation [CAP], soluble egg antigen [SEA], and adult worm antigen [AWA] were evaluated for diagnosis of Schistosoma mansoni infections. For each antigen, serum IgM, IgG, IgA, IgE, IgG1, IgG2 and IgG4 and secretory IgA in unstimulated saliva, stimulated saliva arid stool were quantitatively determined in samples from 116 Schistosoma mansoni infected subjects and 50 normal controls. Cut off values and evaluation parameters were calculated from receiver operating characteristic [ROC] curve. With serum samples, CAP-IgG, CAP-IgG1, SEA-IgG, SEA-IgG1, AWA-IgG1 and AWA-IgG4 were the best assays showing sensitivities of 94.8, 91.4, 95.7, 94.8, 91.4, and 94.8%, respectively, and specificities of 100, 92, 96, 100, 92, and 100%, respectively. With secretory IgA, stimulated saliva SEA and AWA-IgA, and stool SEA-IgA showed the best results with sensitivities of 85.4, 93.1, and 89.7%, respectively, and specificities of 100, 92, and 96%, respectively. In conclusion, different antibody classes determined showed high sensitivities and specificities in diagnosis of active schistosomiasis. Secretory IgA against Schistosoma mansoni antigens showed promising sensitivities and specificities, which make it a helpful tool in diagnosis of active schistosomiasis in the future, as it is an easy non invasive technique, which may help in epidemiological studies
ABSTRACT
The study objective was to find if serum specific suppressive activities on Lymphocyte transformation in response to Schistosoma mansoni [S. mansoni] antigens, usually present in serum of chronic S. mansoni infected patients, are permeable through the placenta from S. mansoni infected mothers to their newborns. Also, to find if such transferred activities are maintained during breast feeding and after weaning. Control group of 8 normal mothers and their offspring and 3 study groups of 13, 11, 11 S. mansoni infected mothers and their newborns, breast-fed infants and weaned children were included in the study. Proliferative response of Lymphocytes, from S. mansoni donors, to S. mansoni soluble egg antigen [SEA] and adult worm antigen [AWA], in presence of serum from each infected mothers groups, showed significantly higher suppressive activity than when the same lymphocytes were incubated with the same antigens in presence of serum from normal mothers group. This suppressive activity was transferred from S. mansoni infected mothers to their newborns' serum and maintained in their barest-fed infants' serum as donors' lymphocytes showed significantly higher suppressive activity in presence of serum from these two groups than in presence of serum from offspring of normal mothers. Serum from weaned children of S. mansoni infected mothers still showed suppressive activity significantly higher than serum from offspring of normal mothers but significantly lower than suppressive activity of serum from newborns and breast-fed infants of S. mansoni infected mothers. No significant difference in suppressive activity in presence of serum from different groups when donors' lymphocytes were stimulated by PHA indicating that this transferred suppressive activity is specific to S. mansoni antigens. Interleukin-10 [IL-10] production by donors' lymphocytes when stimulated by different stimulants showed results parallel to suppressive activity. Also, IL-10 production by donors' lymphocytes when stimulated by SEA and AWA in presence of serum from offspring of S. mansoni infected mothers showed highly significant positive correlation with suppressive activity of donors' lymphocytes when stimulated by the same antigens in presence of the same serum [P = 0.001 and < 0.001 respectively]. The parallelism and correlation between effect of serum on suppressive activity and IL-10 production suggest that IL-10 production is one of the main mechanisms by which serum affect lymphocytes transformation. These results suggest that the antischistosomal immunological status of S. mansoni infected mothers affects the future of their offspring when infected with S. mansoni and encourage studying the use of effective pathology modulating vaccines with mothers during pregnancy and lactation