Efficiency of immunization of mice with irradiated antigen against schistosoma mansoni infection in comparison with praziquantel

The present study is an attempt to evaluate the protective effect of schistosomula antigen and the current antischistosomal drug praziquantel [PZQ] as a reference drug on mice infected with S. mansoni. Mice were vaccinated by irradiated or non-irradiated schistosomula antigen, both at a dose of 100 ug protein/mice once weekly for 3 weeks, before infection with a live cercariae and compared with the treatment with i.m. injection of praziquantel at a dose, of 40 mg/kg b.wt. 4 times once weekly for 4 weeks after infection. The degree of resistance or protection induced by immunization and chemotherapy was assessed 45 days post-infection and evaluated by physiological, parasitological, immunological as well as histological parameters. The results indicated that immunization with lambda irradiated antigen at 20 Krad or the treatment with PZQ resulted in significant reduction in ova count in liver and intestine tissues more than those vaccinated with non-irradiated antigen compared with infected group. Immunized group with irradiated antigen and the group treated with PZQ showed a significant decrease in liver enzymes activity [ALT, AST and lambda -GT], while in immunized group with non-irradiated antigen, there was a significant increase in AST and lambda -GT as compared to infected group. The level of alkaline phosphatase enzyme was significantly increased in all investigated groups compared to infected one. Treatment with PZQ or immunization with irradiated or non-irradiated schistosomula antigen induced amelioration in serum IL-10 and TNF-alpha. Scanning electron microscope demonstrated normal mature worms in infected group after 45 days from infection. In contrast, many changes were detected in the rest groups as alterations in the tegument, implosion of tubercles which appeared pealed and sloughed off and most of the spines were detached and separated. Histological examination of liver sections of infected mice revealed lobular cellular infiltration and cloudy swelling in hepatocytes with occurrence of necrotic foci. Also, granuloma of infiltrating cells was noticed around the portal structures and inbetween the degenerated cells. Congested portal vein could be seen lodged with adult worms and the portal tracts showed fibrous thickening. Whereas, the lung revealed destructed bronchioles which appeared surrounded by intense inflammatory foci. Thickened interalveolar septae were also marked, however many alveoli appeared with shed destroyed epithelium. Moreover, peribronchiolar and perivascular fibrosis was quite prominent. Gross pathological alterations were observed in both liver and lung of immunized groups with non-irradiated antigen. In controversy, immunization with irradiated antigen can reduce the granulomatous reaction and collagen deposition. There are also little inflammation and less congestion, however the hepatic and pulmonary architectures appeared otherwise normal. The present histological findings proved that PZQ has a valuable schistosomicidal effect but some pathological changes are still detectable. On the whole, it could be concluded that irradiated antigen produced marked protection against S.mansoni infection and this may reflect its possible beneficial effect on the diseased liver and lung

Early post-treatment immunoglobulin profile in human schistosomiasis

In a trial at determining the most relevant immunoglobulin isotype that could reflect success of praziquantel treatment, an ELISA using soluble egg antigen [SEA] was applied on sera of Egyptian patients suffering from active intestinal schistosomiasis without hepatic complications determining the levels of IgE, IgA, IgM, IgGl, IgG2, IgG3 and IgG4 raised against the SEA, bot0h pre- and early post-treatment. The positive results obtained to all anti-SEA immunoglobulin isotypes before treatment support the usefulness of this technique in the diagnosis of schistosomiasis. Except for IgG3 subclass, a statistically significant correlation was found between egg output-reflecting intensity of infection-and the different immunoglobulin levels, especially anti-SEA IgG4. When repeating the assay 5-6 months after treatment, the immunoglobulin levels showed either a rise [in case of IgE] or a drop [in case of IgA, IgM and IgG1-4], all of statistical significance; yet IgG1-4 were still positive. So, ELISA could not give a definite indication of cure after anti-bilharzial treatment. IgE, IgG2 and IgG4 were revealed to be the most significant immunoglobulin isotypes at the post-treatment level, both statistically and due to their implications on resistance/susceptibility to re-infection and also due to the correlation of IgG4 with the tendency to develop periportal fibrosis. Conclusively, although not having defined a particular Ig isotype as marker for cure, it exposed the urge for early post-treatment determination of IgE and IgG4 isotypes which could serve as markers for picking up high risk patients susceptible to re-infection or liable to develop bilharzial periportal fibrosis and who might benefit from a second course of specific treatment

Evaluation of the levels of circulating carbohydrate antigen and anti-SWAP antibodies in patients with active Schistosoma haematobium infection and its relation to morbidity changes

The immune responses of schistosomiasis and its relation to morbidity changes is important to understand the pathogenesis of this disease. The aim of this study is to evaluate the levels of circulating antigen and anti-SWAP antibodies and its relation to morbidity changes in patients with active Schistosoma haemtobium infection. An antigen enzyme-linked immunosorbent assay [ELISA] employing monoclonal [mAb] 128C3/ 3/21 was used to detect circulating parasite-derived antigen in the sera of 35 of actively infected schistosoma haematobium patients [31 males and 4 females, 5 to 25 years of age] seen in the out patient clinic of Assiut University Hospital. AntiSWAP [soluble adultworm antigen preparation] immunoglobulins IgG1. IgG4 and IgE were performed for 25 of them. Patients were treated with praziquantel [PZQ] and re-evaluated after 1, 3, and 6 months. Changes in morbidity were evaluated using ultrasonographic grading of urinary bladder lesions. It was found that all patients had significantly high levels of circulating antigens in their sera i. e. above the cut-off value. The antigen level fell significantly in the follow cup visits [p<0.001]. Although the mean antigen level was still significantly reduced [p<0.001] at 6 months visit, 16 patients had high mean antigen level and 9 had rising levels of antigenaemia, reflecting reinfection in 6 patients and persistence of infection in the others. On the other hand, all patients had positive ELISA reaction for IgG1 and IgG4, while 5 patients had negative reaction for IgE through the different visits before and after treatment. The decrease in the mean levels of IgG1 and IgG4 were statistically significant only after 6 months of treatment, but the mean levels of IgE showed significant drop at 3 and 6 months of treatment. A significant correlation was found between the circulating antigen and the anti SWAP IgE during the active infection, but no significant correlation was found between the antigen level and IgG1 and IgG4. There was a significant correlation between the level of circulating carbohydrate antigens and morbidity changes of the urinary bladder. On the other hand there was no significant correlation between the anti-SWAP antibodies and morbidity changes. We conclude that ELISA assay for detection of circulating carbohydrate antigen of S.haematobium is valuable and sensitive in diagnosis of active infection, measurement of intensity of infection and detection of reinfection as well as evaluation of the efficacy of treatment. Its level correlates with anti-SWAP IgE during active infection. In addition it correlates significantly with

Teniasis-cisticercosis como problema de Salud Pública / Taeniasis-cysticercosis as a Public Health problem

Las cestodiasis de importancia sanitaria principal en México, son causadas por la T. solium y T. saginata. El cerdo es el huésped intermediario del Cysticercus cellolosae (fase larvaria de la T. sodium), aunque el hombre y el perro pueden ser infectados, con lesiones del tejido subcutáneo, músculo estriado, ojos y cerebro. La teniasis-cisticercosis humana se ha relacionado epidemiológicamente con los malos hábitos higiénicos, la insalubridad ambiental y en ausencia de un tratamiento adecuado, la infección por Taenia adulta suele persistir por varios años. La niclosamida, el albendazol y el praziquantel son medicamentos activos contra los céstodos adultos, siendo especialmente interesante la acción del praziquantel contra las fases larvarias de la T. saginata en los bovinos y el C. cellulosae en el hombre, con pocos efectos colaterales, siendo un producto no embriotóxico, ni teratogénico y sin efectos mutagénicos