Evaluation of Schistosoma haematobium adult and egg antigens by ELISA in diagnosis of urinary schistosomiasis

The aim of this study was using ELISA for detection of anti-Schistosoma haematobium antibodies in both sera and urine of patients with urinary schistosomiasis. Thirty three sera and urine samples were collected from patients with acute schistosomiasis in Diyala Province, east of Iraq in 2006. Their diseases were confirmed by finding S. haematobium ova in urine examination. Sera and urines of 10 healthy individuals as well as 5 patients with hydatidosis and 5 patients with acute toxoplasmosis were examined as well. Samples were examined for antibody detection by ELISA method. The antigens used in this study were egg and adult antigens. All positive samples [sera and urines] showed positivity by using egg antigen whereas the negative control samples were negative; only two samples with hydatidosis were positive with using serum sample whereas with urine sample only one sample was positive. In this study, the best sensitivity and specificity obtained when using urine and adult antigen. Antibody detection by using urine is a useful, simple, and sensitive method for diagnosis of schistosomiasis

Evaluation of Schistosoma haematobium 27-29 KDA antigen for immunodiagnosis of Schistosomiasis haematobium

The study demonstrated the immunodiagnostic potential of differrent Egyptian human Schistosoma haematobium antigens. ELISA was used to measure the levels of total immunoglobulin G [IgG] and IgG4 antibodies [Abs] against S. haematobium adult worm antigens [Ags] [SAWA], excretory/ secretory Ags [E/S] and cysteine proteinase Ag [27-29 kDa] for diagnosis of schistosomiasis. SDS-PAGE profiles of S. haematobium Ags showed several bands for SAWA, E/S and 27-29 kDa Ags which are characteristic of infections with Schistosoma spp. Purified protein fraction showed a single homogenous band of 27-29 kDa. For summarizing the potency of S. haematobium Ags, sensitivety rate, negative predictive value and diagnostic efficacy were calculated between data of 40 human patients in ELISA. SAWA Ag recorded 85.0%, 77%, 90.0% with total IgG and 90.0%, 83% and 93.3% with IgG4 isotype, respectively. While, E/S recorded 87.5%, 80%, 92.0% with total IgG and 92.5%, 87%, 95.0% with IgG4 isotype, respectively. Purified 27-29 kDa Ag presents the higher significant [P<0.01] results recording 90.0%, 83%, 93.3% with total IgG and 97.5%, 95%, 98.3% with IgG4 isotype, respectively. The results proved that combining the detection of IgG4 isotype using the 27-29 kDa Ag in sera of schistosomiasis haematobium patients in ELISA test could represent an effective immunodiagnostic tool for detecting infection in low worm burden population. This test could be useful in sero-epidemiolocal studies in low endemic areas and in diagnosis of infection in travelers to schistosomiasis endemic areas

Anti-malaria humoral responses in children exposed to Plasmodium falciparum and Schistosoma haematobium

Antibody responses directed against the Plasmodium falciparum antigens, total extract, anti-merozoite surface protein-3 (MSP3b) and glutamate-rich protein (Glurp-R0) were studied in 42 children exposed to both Schistosoma haematobium and P. falciparum infections. The association between levels of the anti-malaria IgG subclasses and IgM with host age, sex, schistosome infection intensity and schistosome specific antibodies was studied before chemotherapeutic treatment of schistosome infections. This showed a significant negative association between schistosome infection intensity and levels of IgG1, IgG3, and IgG4 directed against malaria total extract antigen, and a positive association between levels of anti-schistosome soluble egg antigen IgG2, IgG3, and IgG4 and levels of the same subclasses directed against malaria total extract antigens. The effect of treating schistosome infections with praziquantel on malaria specific responses was also studied. This treatment resulted in increases in significant IgG4 levels against MSP3b and IgM against Glurp R0. Treatment also resulted in a significant decrease in IgG4 levels against Glurp R0. Host age, sex or pre-treatment infection intensity was not associated with the magnitude of change in the two IgG4 responses while males showed a significantly higher increase in levels of IgM. The results suggest cross reactivity between schistosome and malaria antigens in this population.

Urinary tract pathology in Schistosoma haematobium infected rural Nigerians.

Parasitological investigation assessing the ova of Schistosoma haematobium in the urine of 138 volunteers in Ihieve-Ogben, Edo State, Nigeria revealed 43 positive results (31.2%). Children had a higher prevalence of urinary schistosomiasis 30 (41.1%) than their adult counterparts 13 (20.0%) and this difference was statistically significant (t = 8.89, p > 0.01). More volunteers had light intensity of infection 27 (19.6%) than heavy infection 16 (11.6%) and this difference was statistically significant (chi2 = 22.90, p>0.05). Ultrasonographic investigations carried out on these 43 S. haematobium infected volunteers revealed ten pathological conditions, including abnormal wall thickness 24 (55.8%), abnormal shape 30 (69.8%), irregular bladder wall 12 (27.9%), masses 10 (23.3%), pseudopolyps 2 (4.7%), echogenic particles 30 (69.8%), residual volume 12 (27.9%), calcifications 24 (55.8%), hydroureter 10 (23.3%) and hydronephrosis 8 (18.6%) when compared to control subjects which lacked bladder and kidney abnormalities. These pathological conditions were slightly more common in the volunteers with heavy infection than those with light infection, but this difference was not statistically significant (t = -2.19, p < 0.02). More pathological conditions were found in children than in adults; this finding was statistically significant (t = 3.23, p > 0.03). Hydronephrosis and hydroureter were not found in the volunteers with light intensity of infection.

Immunolocalization of schistosoma mansoni and schistosoma haematobium antigens reacting with their Egyptian snail vectors

The reaction of the haemolymph and the tissue of infected intermediate hosts, Biomphalaria alexandrina and Bulinus truncatus to Schistosoma mansoni and S. haematobium antigens were investigated using the indirect immunoperoxidase technique. A new technique, Agarose cell block was used in collection of haemolymph which helped in collecting plenty of well formed cells in comparison to the ordinary one using the cytospin. Collected haemolymph and prepared tissues of uninfected and infected B. alexandria and B. truncatus were fixed and then reacted with anti-S. mansoni and anti-S. haematobium IgG polyclonal antibodies. The haemolymph and tissue of infected B. alexandrina and B. truncatus gave a positive peroxidase reaction represented by a brown colour. In haemolymph, the positive peroxidase reaction was detected mainly in the cytoplasm of the amoebocytes. In the tissue, it was detected in epithelial cells lining the tubules, male cells in the lumen of the tubules and in female oogonia cells along the periphery of the tubules. The similarity in the strength and distribution of positive reaction in B. alexandrina and B. truncates was observed as compared to control. Thus, the immunoperoxidase technique proved to be an effective indicator for the schistosome-antigen in the snails

Clinical and laboratorial evaluation of urinary schistosomiasis in Brazilians after staying in Mozambique

Nós examinamos 87 brasileiros de um grupo de 132 que, entre julho e novembro de 1994, participaram de um missão de paz em Moçambique. Eles serviram em uma área endêmica de esquistossomose haematóbica e nadaram no rio Licungo em períodos de lazer. A idade aritmética deles era 31 anos e todos eram do gênero masculino. O exame de urina revelou que 30 (34,5%) eliminavam ovos de S. haematobium e 55 (63,2%) tinham sorologia positiva pelo teste enzyme-linked immunoelectrotransfer blot com antígeno microsomal purificado de vermes adultos de S. haematobium. Eosinofilia foi encontrada em 30 (34,5%), haematuria em 26(29,9%), disúria em 32(36,8%) e dor lombar em 36(41,4%). Todos que eliminavam ovos pela urina tiveram sorologia positiva. Entre os 25 pacientes com sorologia positiva e sem ovos de S. haematobium no exame de urina, 13 eram sintomáticos e 12 assintomáticos. O tratamento pelo Prazinquantel nos 30 pacientes com urina positiva para ovos de S. haematobium apresentou 70% de cura parasitológica.

The impact of repeated treatment with praziquantel of schistosomiasis in children under six years of age living in an endemic area for Schistosoma haematobium infection

Praziquantel was given every eight weeks for two years to children aged under six years of age, living in a Schistosoma haematobium endemic area. Infection with S. haematobium and haematuria were examined in urine and antibody profiles (IgA, IgE, IgM, IgG1, IgG2, IgG3, and IgG4) against S. haematobium adult worm and egg antigens were determined from sera collected before each treatment. Chemotherapy reduced infection prevalence and mean intensity from 51.8 percent and 110 eggs per 10 ml urine, respectively, before starting re-treatment programme to very low levels thereafter. Praziquantel is not accumulated after periodic administration in children. Immunoglobulin levels change during the course of treatment with a shift towards 'protective' mechanisms. The significant changes noted in some individuals were the drop in 'blocking' IgG2 and IgG4 whereas the 'protecting' IgA and IgG1 levels increased. The antibody profiles in the rest of the children remained generally unchanged throughout the study and no haematuria was observed after the second treatment. The removal of worms before production of large number of eggs, prevented the children from developing morbidity

T cell clones from Schistosoma haematobium infected and exposed individuals lacking distinct cytokine profiles for Th1/Th2 polarisation

T cell clones were derived from peripheral blood mononuclear cells of Schistosoma haematobium infected and uninfected individuals living in an endemic area. The clones were stimulated with S. haematobium worm and egg antigens and purified protein derivative. Attempts were made to classify the T cell clones according to production of the cytokines IL-4, IL-5 and IFN-gamma. All the T cell clones derived were observed to produce cytokines used as markers for the classification of Th1/Th2 subsets. However, the 'signature' cytokines marking each subset were produced at different levels. The classification depended on the dominating cytokine type, which was having either Th0/1 or Th0/2 subsets. The results indicated that no distinct cytokine profiles for polarisation of Th1/Th2 subsets were detected in these S. haematobium infected humans. The balance in the profiles of cytokines marking each subset were related to infection and re-infection status after treatment with praziquantel. In the present study, as judged by the changes in infection status with time, the T cell responses appeared to be less stable and more dynamic, suggesting that small quantitative changes in the balance of the cytokines response could result in either susceptibility or resistant to S. haematobium infection

Um antígeno espécie e estágio-específico para o schistosoma haematobium. Identificaçäo através de anticorpos monoclonais a partir de imunizaçäo de camundongos Balb/C com antígenos ovulares solúveis / Species-specific-antigens for schistosoma-haematobium: Identification by monoclonal antibodies produced of Balb/C mice immunized with soluble egg antigens

No presente estudo, relata-se a identificaçäo e caracterizaçäo imunoquímica parcial de antígenos específicos do Schistosoma haematobium reconhecidos através de anticorpos monoclonais murinos. Os anticorpos monoclonais foram produzidos em camundongos Balb/C imunizados com antígenos ovulares solúveis por via intraperitonial. Este trabalho contribui para a identificaçäo de antigenos do S. haematobium que säo espécie-específicos e que tambem só foram detectados nos ovos dos parasitas, sendo também estágio-específicos. A comparaçäo da sequência parcial de aminoácidos de dois peptídeos tripticos de banda antigenica reconhecida pelo anticorpo monoclonal 2D14E8 em membrana de nitrocelulose com outras sequências de proteínas conhecidas revelou, nos dois peptídeos, uma homologia com a proteína "heat-shock" ou proteína de estresse 70 presente em várias espécies animais, incluindo o homem e o S. mansoni

The susceptibility of adult schistosomes to immune attrition

Mouse infection models are described that demonstrate reduction of egg production in Schistosoma haematobium infections and both worm loss and reduced fecundity in S. bovis infections. Neither phenomenum could be shown in S. mansoni infected mice. The immunological basis for these anti-adult responses was inferred by comparison with infections in T-cell deprived mice and by the serum transfer of the ability to reduce a S. bovis worm burden into immunocompromised hosts. Vaccination with irradiation attenuated parasites was also shown to have consequences for the adults of a challenge infections of S. haematobium and S. bovis specifically. Prior vaccination resulted in an abrogation of the anti-fecundity and adult worm elimination that occurred in non-vaccinated similary infected mice. hese models are being used to define the targets and mechanisms involved in anti-adult attrition. A serological assay, quantitation of a circulating antigen (CAA) has been assessed for its ability to measure worm burdens of different species of schistosome in mice. This assay will be used to question whether anti-adult immunity contributes to the pattern of infection with S. mansoni and S. haematobium in man