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.

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

Epidemiology and immunodiagnosis of schistosomiasis haematobium in low endemic area in Egypt

A survey was performed in Behbeet Village in Giza Governorate including 370 individuals [172 males and 198 females] representing 10% of the house holds. Clinical, stool, urine and serological tests accompanied by a questionnaire were applied to all participants to find out the prevalence, intensity of infection of S. Hematobium, underlying sociodemographic factors, morbidity indicators and the awareness and treatment status among the infected population. It was revealed that the overall prevalence of S. Hematobium based on the detection of eggs in urine was 18.1%, while the prevalence of antibodies to S. Hematobium species specific microsomal antigen was 57.6% detected by enzyme-linked immuno-transfer blot [EITB]. The highest age specific prevalence and intensity of infection were detected among school children in the early teenage. Males were at a higher risk of contracting infection than females with a sex ratio of 2.5: 1. Occupational and recreational water contact were significantly more frequent among the egg positives than the negative ones. Present history of hematuria and microhematuria detected by reagent strips had the strongest association with S. Hematobium infection followed by leucocyturia and dysuria

Depressed cellular immunity in chronic schistosoma haematobium infection may lead to malignancy

The human immune system is actively involved in the host response to schistosome infection as it is exposed to multiple antigens [ova, worms, cercariae] of the parasite. These changes were thoroughly studied in Schistosoma mansoni, but hematobium infection was not equally investigated, since the finding of pure hematobium infection is difficult. The solitary hematobium infection is found only in certain areas of Upper Egypt. The humoral and cellular immune response was thus studied in 65 cases with pure Schistosoma hematobium cases in different clinical stages: Early active and late chronic complicated cases. The study revealed that humoral response was stimulated by Schistosoma hematobium infestation. but was not specific to any of the mentioned complications. Results are given in detail

Effect of anti-bilharzial treatment [praziquantel] on urothelium improvement A histopathological and immunological study

The effect of therapy by praziquantel on bilharzial urothelium was studied on 60 patients, 30 cases and 30 control. Cystoscopic and bladder biopsy was taken before and after treatment with praziquantel 40 mg/kg/ body weight for 4 doses one week apart. Cystoscopy after treatment revealed disappearance of the acute lesions: acute ulcers, edema and congestion. But no improvement of chronic lesions; and no changes were found among control group. Histopathological examination shows complete improvement of the acute lesions, granulomatous reaction, degeneration of the living ovae; but no noticeable effect upon the chronic lesions as stromal fibrosis, squamous metaplasia, and no histopathological changes shown among control group. Immunofluorescent deposition positivity was studied in bilharzial Antigen, IgM, IgA and IgG. Bilharzial antigen and IgM immunofluorscent deposition positivily can be used as a marker for detection of the response of treatment with praziquantel especially in acute lesions

Immune response in bilharzial farmers [uncomplicated and complicated cases]

This study was done in the Outpatient Clinic of Zagazig University Hospital and in the Bacteriology Department of Zagazig University during the year 1991. The aim was to evaluate the immune response [humoral and cellular] of bilharzial patients in various stages of infection through quantitation of specific antibodies using indirect hemagglutination test [IHAT] and quantitation of sensitized T- lymphocytes and their subpopulations using indirect immunofluorescent technique. The study included 25 normal healthy individuals, 25 simple urinary bilharziasis, 25 simple intestinal bilharziasis, and 25 hepatosplenic patients. There was a marked increase in the mean titer of IHAT of bilharzial groups compared with normal controls, but there was no significant statistical difference among the bilharzial groups. The study revealed a decrease in the means of total leucocytic count [TLC], absolute lymphocytic count [ALC], T3+ count, T4+ count and T4+/T8+ ratio of bilharzial groups. Comparable with the normal cases, T8+ counts of bilharzial groups were within normal. There were highly statistically significant lower mean values of total leucocytic count [TLC], T4+ counts, and T4+/T8+ ratio of complicated intestinal [hepatosplenic] group comparable with simple bilharzial groups

Técnica de hemaglutinación indirecta: su uso en la enfermedad esquistosomiasica para fines evolutivos; trabajo preliminar / Indirect hemagglutination technique: its use in shistosomiasis for evolutive purposes; preliminary work

Se estudian 52 pacientes con Schistosoma haematobium y 28 con Schistosoma mansoni. Se comparan los resultados de los estudios parasitológicos con el tiempo de evolución de la enfermedad, la media de huevos encontrada y los resultados mediante la técnica de hemaglutinación. De dicha comparación se obtuvieron conclusiones

Study of the histocompatibility in different clinical presentation of urinary schistosomiasis

In Egypt schistosomiasis is prevalent among farmers who are occupationally exposed to the heavily infested water. Many complications are present among these patients, However, it is not uncommon to find cases without evidence of any complication of the disease although they all live under the same environmental conditions; many explanation have been postulated to explain these differences such as : heaviness, repitition and chronicity of infestation. However, a genetic susceptibility cannot be excluded. The aim of this work was to study the pattern of the major histocompatibility system in patients with various clinical presenrations due to Schistosoma haematobium infestation and its complications. The study included 91 unrelated patients with urinary schistosomiasis as well as 100 unrelated Egyptian control.Patients were classified into: Group I, 22 cases with simple urinary schistosomiasis. Group II, 22 cases with benign Bilharzial lesions of the bladder. Group III, 26 cases with malignant lesions in Bilharzial bladder. Group IV, 21 cases with hepato-splenic Bilharziasis. All groups of patients and controls were tissue typed using the microdroplet lymphocytotoxicity technique was done. Some human leucocytic antigen [HLA] had positive associations [HLA-B5, BW[4] AND BW[6]] and the other had negative associations [HLA-A9] with Schistosoma haematobium infestation.The incidence of HLA-B5 antigen was found to be significantly increased among cases of group I, II and III, while HLA-B5, B8, BW4 and BW6 antigens were found to be significantly increased in cases of group IV when each group was compared with the controls. Those possessing such antigens were considered a high risk people and should be given more care if they develop Schistosoma haematobium infestation