Effect of praziquantel on certain immune responses of schistosomal Egyptian patients. I. Changes of specific immunoglobulins.

Specific antischistosomal IgG, IgM, and IgE were estimated by ELISA in 117 rural school students before specific treatment with praziquantel monthly for 3-4 months thereafter. IgG and IgM were estimated as percentage of bound antibodies. IgE was estimated by avidin-biotin ELISA (AB-ELISA) as IU/ml using a panel of known IgE standards. Soluble surface Schistosoma mansoni adult worm antigen was used for all estimates. Total IgE was estimated in a smaller group by an ELISA kit. The percentage of specific IgE was calculated. A group of endemic controls (22 students) and non-endemic controls (17 cases) were included. Statistical analysis of results showed the specific immunoglobulins to be significantly reduced 2 months after treatment of the schistosomal cases. These reduced levels, however, were still significantly higher than those of controls. The presence of early hepatosplenomegaly and the co-existence of other parasites had no significant influence on the results. No correlation could be established between the levels of specific antischistosomal IgG, M and E and the intensity of infection. The significance of these results is discussed.

Effect of praziquantel on certain immune responses of schistosomal Egyptian patients. II. Cell-mediated lymphoproliferative response.

The lymphoproliferative blastogenic responses to mitogens, PHA and Con A, and to schistosome-derived antigens. S. mansoni worm and egg, were tested in 35 schistosomal patients and 10 healthy controls. Of the former group, 18 patients had intestinal mansoniasis and 17 had mansoniasis with hepatosplenomegaly. The test was repeated 2 weeks and 1 and 2 months after treatment with praziquantel. The delayed intradermal test for schistosomiasis was performed on 25 of the schistosomal patients and was repeated 1 month after treatment. Statistical analysis of results of lymphoproliferative blastogenic responses showed no significant differences between the control and the two schistosomal groups in response to mitogens. The group with intestinal mansoniasis responded significantly to both schistosomal antigens, compared to the control and hepatosplenic groups. Their proliferative responses showed a significant rise 2 weeks after treatment, then a gradual drop at 1 and 2 month intervals. The hepatosplenic group responded significantly to worm antigen before treatment; their proliferative responses to both schistosomal antigens showed a significant rise 2 weeks after treatment and remained raised thereafter. No relationship was established between either of the two schistosomal groups for age, intensity of infection or positive delayed intradermal reaction.

Evaluation of the ELISA test as an epidemiological tool in schistosomiasis.

The ELISA test was studied to assess its applicability in epidemiological surveys of schistosomiasis. Specimens of serum, stool and urine from persons attending an outpatient clinic in an endemic area for S. mansoni and S. haematobium in Egypt were tested in the laboratories of the Theodor Bilharz Research Institute, Cairo. The ELISA test results were compared with parasitological findings and with the results of indirect immunofluorescence and indirect hemagglutination tests as reference data. The ELISA test showed an excellent sensitivity and specificity for both infections; the reading and recording of the extinction rates can be automated by using in time and money. The test can be strongly recommended for epidemiological surveys.

Prevalence of HBs-Ag in schistosomiasis. (A) general aspects.

Nine hundred and sixteen schistosomal patient together with 97 non-schistosomal controls were examined for the presence of HBs-Ag and anti-HBs in their sera by counter-immunoelectrophoresis (CIEP). The results are reported and statistically analysed. HBs-Ag, anti-HBs and the exposure rate were found significantly higher in schistosomal patients than in controls. The frequency of HBs-Ag was not significantly different in the active and inactive schistosomal groups, while the anti-HBs was significantly higher in the inactive group. S. mansoni-infected cases showed significantly higher frequency of HBs-Ag and anti-HBs than cases with S. haematobium. The prevalence of HBs-Ag was highest between 20-39 years of age in the schistosomal group, while the anti-HBs was maximum at the age of 30-39 years. There were no sex differences in the prevalence of HBs-Ag and anti-HBs in both schistosomal and control groups. However, a significantly higher frequency of anti-HBs was found between male patients and male controls. The same was true for females. Patients with history of parenteral anti-bilharzial treatment and blood transfusions were accompanied with significantly higher percentage of HBs-Ag and anti-HBs. The importance and significance of the results are discussed.

Prevalence of HBs-Ag in schistosomiasis: B-frequency in various stages of schistosomiasis.

The study included 916 schistosomal patients and 97 controls. The prevalence of HBs-Ag and anti-HBs was significantly higher in the bilharzial patients compared to controls. Their frequency was higher in the ascitic than the hepatosplenic group, and the difference between each and the simple group was highly significant. Cases with current jaundice showed highly significant frequency of both HBs-Ag and anti-HBs compared to those with no history or manifest jaundice at the time of study. In addition, cases with raised bilirubin, SGPT and SGOT showed significantly higher frequency of HBs-Ag and anti-HBs compared to cases having normal levels. On the other hand, the frequency was not affected by the level of serum alkaline phosphatases. As regards liver pathology, cases with mixed pathologic picture showed significantly higher frequency of both HBs-Ag an anti-HBs compared with those having pure schistosomal lesions.

Delayed hypersensitivity to specific antigen and hetrologous PPD antigen in patients infected with Schistosoma mansoni and/or Schistosoma haematobium.

181 cases with schistosomiasis were skin tested with S. mansoni antigen and tuberculin (PPD) after complete clinical and parasitological examination. Their results were compared to a control group of 89 non bilharzial cases. The positivity of tuberculin reaction was found to be less frequent in schistosomiasis (37.5%) when compared to non schisto. controls (55.0%). This low reactivity was more manifest in the advanced stages of the disease. The delayed skin reaction with S. mansoni antigen was seen in 52.4% of schisto. cases while non of the control showed any positivity. There are more delayed skin test positives with the advance of the disease.

Preliminary investigation of bilharzial patients for the presence of Australia antigen using latex agglutination test.

THE AUSTRALIA antigen was studied by the use of a reversed passive latex agglutination test in the sera of 250 cases, mostly bilharzial. The results were analysed in relation to age, clinical presentation, bilharzial infestation, antibilharzial treatment, jaundice and serum bilirubin. It was found that, the test was significantly more positive in hepatosplenic cases, in those with past history of bilharziasis, in those with jaundice and in those with higher serum bilirubin level. While no significant difference was found in relation to age, and to history of antibilharzial treatment.