RESUMO
An antigen-capture ELISA using monoclonal antibody (MAb) 128C3/3/21 was used to detect circulating parasite-derived antigens in the sera of patients actively infected with Schistosoma haematobium (31 males and four females, 5-25 years of age). The assay had a sensitivity of 100% (35 of 35 patients with antigen levels > 80 ng/ml) and a specificity > 99%. We used this ELISA to monitor antigenemia before treatment and one, three, and six months after treatment with a single oral dose of praziquantel (PZQ) (60 mg/kg in 20 patients or 40 mg/kg in 15 patients) and compared our findings with those indicated by other measures of disease progression. Circulating antigen levels decreased drastically after PZQ treatment (P < 0.001), with a significantly higher decrease occurring after treatment with 60 mg/kg than with 40 mg/kg. Although the mean antigen level was still significantly reduced (P < 0.001) at six months after treatment, 16 patients remained antigen-positive after six months, and nine had increased levels of antigenemia, reflecting reinfection in six patients and persistence of infection in another. We observed a correlation (r = 0.6, P < 0.01) between the level of circulating antigen and the intensity of infection as measured by egg count. We also found a direct relationship (P < 0.001) between antigen level and the severity of the disease as monitored by ultrasonography. We conclude that our ELISA may be a useful adjunct to other methods, such as ultrasonography, for monitoring the course of S. haematobium infection and treatment.
Assuntos
Antígenos de Helmintos/sangue , Schistosoma haematobium/imunologia , Esquistossomose Urinária/imunologia , Adolescente , Adulto , Animais , Anticorpos Anti-Helmínticos/sangue , Anticorpos Anti-Helmínticos/imunologia , Anticorpos Monoclonais/imunologia , Antiplatelmínticos/uso terapêutico , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Masculino , Contagem de Ovos de Parasitas , Praziquantel/uso terapêutico , Esquistossomose Urinária/diagnóstico , Esquistossomose Urinária/tratamento farmacológico , Sensibilidade e Especificidade , Urina/parasitologiaRESUMO
The transfer of maternal antibodies to Friesian and buffalo calves born of dams vaccinated against rinderpest was through colostrum only. Colostral antibody titers at the time of parturition were higher than the serum titer. Two hours after suckling, a high level of rinderpest neutralizing antibodies was detected in the sera of newborn animals. The half-life of maternal antibodies in buffalo and Friesian calves was found to be approximately 33 and 29 days respectively. By the age of 7-8 months, 60 per cent of buffalo calves and 80 per cent of Friesian calves had no detectable levels of rinderpest neutralizing antibody.
