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Cercarial Transformation and in vitro Cultivation of Schistosoma mansoni Schistosomules
Published on: August 16, 2011
Antibody subclass profile and avidity during acute and chronic human Schistosoma mansoni infection
L de G Viana1, A Rabello, N Katz
1Laboratório de Esquistossomose and Laboratório de Pesquisas Clínicas, Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz-FIOCRUZ, Belo Horizonte, Brazil. ana@cpqrr.fiocruz.com.br
Abstract:
The avidity of IgA, IgM, IgG and IgG subclass antibodies against Schistosoma mansoni soluble egg antigen (SEA) was determined by ELISA in serum samples collected in 1995 from individuals in Brazil with acute (n = 36) and chronic (n = 40) schistosomiasis. Fifteen individuals at the acute phase were also evaluated 6 months after clinical diagnosis. Predominance of low-avidity IgG, IgG1, IgG2, IgG3 and IgA characterized the acute phase. IgG4 was detected in only 2 individuals with acute disease (5.6%). Levels of anti-SEA IgM were similar between the study groups. IgG1 avidity showed the strongest association with the chronological evolution of the infection, presenting 100% of low avidity during the acute infection and reaching 100% of high avidity 6 months after. It is suggested that distinct anti-Schistosoma egg antigens subclass profile and antibody avidity characterize the clinical phases of S. mansoni infection. In particular, determination of anti-SEA IgG1 offers a new tool for the laboratory analysis of the disease.
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