الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
 |  | from | 193 |  |  |
| | | from | 193 | | |
Abstract
Fascioliasis is becoming one of the major health problems in Diagnosis of fascioliasis is mainly based on the direct sitological methods, through detection of parasite ova in the stools However, limitations in sensitivities and ecificities of such techniques can not be overcome. Repeated stool aminations are usually necessary to obtain reliable results of the lensity of infection, yet many cases can still be missed. Several studies have been directed to the serological diagnosis of cioliasis as an adjunct to direct methods. Numerous techniques aye been described, the variability of such techniques is an indication at a satisfactory test regarding sensitivity and specificity is yet to be Tests aiming at antibody detection have not shown to be an altemative for the commonly applied parasitological This is particularly true as antibody levels remain high en after successful treatment. Moreover, antibody detection does 01 give sufficient information about intensity of infection which is nsidered a good parameter of disease morbidity. Diagnostic tests detecting Fasciola antigens are expected to dicate active infection and assess worm burden. Since EIS antigens e released by living flukes, they should be expected to be perfect didates for diagnosis and cure assessment. The present work aimed at detection of circulating f’asciola r i antigens in the sera of infected patients together with determination of of f’asciola antibodies against somatic and metabolic The study of antigen and antibody levels was undertaken in acute and chronic f’asciola patients before and after treatment. The study depended on cases referred to our department either (or parasitological and I or serological testing. IIiAT served as the gold standard for acute cases, and stool examination using the Kato/Katz method served as the gold standard for the chronic cases. Two groups of patients were enrolled in the study: Group I: - Acute f’asciola cases (20) - Chronic f’asciola cases (20) ’Group ll: - Controls (healthy parasite free individuals) (12) - Schistosomiasis cases (to test for the presence of cross reacting antibodies)(20). Blood and stool samples were collected before and after tnclabendazole (TCBZ) therapy at months one, three, six and twelve for acute cases, and one, three and six for chronic cases. The blood intensity of infection, and antibody levels were Somatic f’asciola antigen was prepared and fractionated by Peaks I and 11 were obtained and protein content Fasciola EIS antigen was prepared by washing live intact adult worms, then incubation for four hours at 37°C. The suspension was then centrifuged and protein content determined. The two somatic antigenic fractions I and 11 and the EIS antigen were used in IgM and IgG ELlSA. Chequerboard titrations were carried out, antigen concentration and serum dilutions that gave the best results were determined. The test was then performed using the three antigens at a protein concentration of 5 ~gjml and serum dilutions varied from 1/50 up to 1/150 according to the type of antigen used. An IELlSA was performed to reveal the presence of circulating LIS antigens. It necessitated the following steps: Hyperimmune rabbit serum was prepared by repeated Immunization of rabbits using EIS antigen (dose 0.5-1 mgjml) suspended in complete and incomplete Freund’s adjuvant respectively. The hyperimmune serum together with serial dilutions of the EIS antigen were used to build a standard curve from which ODs of infected patients could be expressed as antigen concentration. Chequerboard titrations were carried out. The test was then performed using EIS antigen at a protein concentration of 5 ~g/ml for coating, serum dilutions 11400, hyperimmune serum 1/20.000 and nnally serial dilutions of the EIS antigen from 1/25 up to 1/12800 as control. Haematological studies revealed cases of mild anaemia. was observed in 100 percent of acute cases and 30 percent of chronic Intensity among chronic cases was either light (35 percent) or moderate (60 percent). Only one case had heavy infection. As regards anti-Fasciola antibodies, in case of acute fascioliasis and with IgM ELISA, sensitivity was 100 percent, 90 percent and 100 percent using Irnctions I, 11 and EIS antigen respectively. In chronic cases and with ~GELlSA, sensitivity was 100 percent, 55 percent and 100 percent respectively. Taking schistosomiasis into consideration, specificity of IgM ~ISA was 75 percent, 70 percent and 80 percent using fractions 1,11 and EIS antigen respectively, and of the IgG ELISA was 75 percent, respectively. 65 percent and 80 percent By IELlSA, sera from all 20 acute patients had detectable antigen levels (~30 percent inhibition ~ 150 ngjml), while sera from chronic patients ; were 70 percent positive. follow up study: In acute cases, the follow up period extended up to twelve Values of the absolute eosinophilic count showed a dramatic the first month and reached normal values six months after As regards the IHA titres, a dramatic drop started one month after treatment to reach an extremely low mean value twelve months ’after treatment. Antibodies against Fasciola antigens showed a gradual slow decrease all through the follow up period. Number of cases showing values lower than the cut off level was four, nine and six cases using 11 and EIS antigen respectively, at twelve months post treatment. Thus IgM ELISA could not lead to a definite conclusion in cure assessment of acute cases. 149. Considering the CFA, a reduction in its level was evident one month after treatment. The rate of seronegativity increased from 40 percent at three months to 65 percent at six months and finally twelve months after lIeatment the cure rate was considered 70 percent. The level of CFA coincided with AEC that reached 75 percent negativity twelve months after treatment. As regards chronic cases, parasitological examination revealed two, four and six cases positive at one, three and six months after treatment recpectively. Absolute eosinophilic counts started 70 percent negative, and ended by 75 percent negative, six months after therapy. Antibody levels were 70 percent and 75 percent positive using fraction I and ~/S antigen respectively six months after treatment. Using fraction 11, OD readings were exceptionally low and reached 85 percent negative six months after therapy. Considering the CFA level, it dropped to negative values in 13 cases, seven cases continued to have detectable antigenemia from one month onwards. The degree of inhibition correlated to the intensity of infection, suggesting a quantitative relationship between circulating antigenemia and parasite burden.