High levels of IgG4 to Schistosoma mansoni egg antigens in individuals with periportal fibrosis

Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal Minas Gerais, Belo Horizonte, Brazil.
The American journal of tropical medicine and hygiene (Impact Factor: 2.7). 06/2002; 66(5):542-9.
Source: PubMed


Specific IgG4 and IgE responses to adult worm antigen and soluble egg antigen (SEA) were examined in 267 individuals from an area in which schistosomiasis mansoni is endemic. Based on information obtained from clinical and sonographic examinations of this sample, the individuals were divided in three groups: 1) 204 individuals without periportal fibrosis, and liver and spleen enlargements; 2) 41 individuals without periportal fibrosis, but presenting with organopathy, with or without organomegaly; and 3) 22 individuals with periportal fibrosis, regardless of their status as having hepatomegaly and/or splenomegaly. Levels of IgG4 to SEA were significantly higher in sera from patients with fibrosis compared with the patients from the other two groups. We also found significantly higher levels of IgG4 against SEA in egg-negative patients with fibrosis compared with egg-negative patients from the other two groups. This report demonstrates a specific humoral response in patients presenting with initial fibrosis, a form of schistosomiasis transient between intestinal and severe hepatosplenic.


Available from: Jeffrey Bethony, Jun 27, 2014
  • Source
    • "Similarly, Bonnard et al. [29] reported that higher levels of IgG4 and IgA against SEA antigens were found in patients with severe schistosomiasis. Moreover, the authors [28], [29] also showed no association between IgE responsiveness measured by direct ELISA against SEA antigens and disease severity. We demonstrated that IgG responsiveness to the S. mansoni antigens, SEA and SWAP, is also positively associated with severe forms of schistosomiasis, defined by clinical examination and by ultrasound measurement. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Studies in murine models and human populations have indicated that the collagen-rich granulomatous response against parasite eggs trapped in the liver is associated with the development of severe hepatosplenic schistosomiasis, characterized by periportal fibrosis and portal hypertension. The role of the humoral response in parasite susceptibility has been well established, but its participation in disease severity remains poorly understood. In this work, we evaluated the relationship between parasite-reactive IgE and IgG levels and schistosomiasis morbidity in infected patients with similar parasite burdens. Ninety-seven Schistosoma mansoni-infected individuals were subjected to clinical examination and abdominal ultrasound analysis. IgG reactivity and IgE concentration against Schistosoma mansoni soluble egg antigens (SEA) and adult worm antigen preparation (SWAP) were evaluated by ELISA assay. Multivariable linear regression models were used to evaluate the relationship between parasite-reactive antibodies and the co-variables investigated. The study population showed low parasite burden (median 30 eggs/g feces), constant re-infection, and signs of fibrosis was detected in more than 30% of individuals. Most infected individuals showed IgG reactivity, and the median concentrations of IgE anti-SEA and anti-SWAP antibodies were 1,870 and 1,375 ng/mL, respectively. There was no association between parasite burden and antibody response or any parameter of disease severity. However, IgG anti-SWAP level was positively associated with morbidity parameters, such as spleen size and thickness of portal vein at the entrance and secondary branch. In contrast, the data also revealed independent inverse correlations between concentration of parasite-reactive IgE and gallbladder wall thickness, a marker of fibrosis in schistosomiasis. The data indicate that IgG anti-SWAP is positively associated with severe schistosomiasis, independently of parasite burden, while high production of parasite-specific IgE is associated with mild disease in the human population. Antibody profiles are good correlates for schistosomiasis severity and could be tested as biomarkers of disease severity.
    PLoS ONE 02/2014; 9(2):e88042. DOI:10.1371/journal.pone.0088042 · 3.23 Impact Factor
  • Source
    • "Moreover, resistance to infection has also been associated with high levels of IgE against crude adult antigen extracts from adult worm (SWAP) (Vereecken et al., 2007). Interestingly, reinfection may occur when elevated levels of IgG4 subclass anti-SWAP are observed (Correa-Oliveira et al., 2000; Hagan et al., 1987; Silveira et al., 2002). Although the Schistosomaspecific IgE levels were not measured in the current work, it is likely that increased total IgE levels may partially reflect a specific antiparasite antibody response. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This study examines the relative contribution of age-specific total IgE levels, eosinophils and water contact behavior to the prevalence and intensity (geometric mean egg counts) of Schistosoma mansoni infection in the poor rural population of Virgem das Graças in northern Minas Gerais State. In bivariate analysis, age was strongly correlated with both prevalence and intensity of infection, while eosinophil levels with prevalence only (p<0.0001); IgE levels and 5 demographic and socioeconomic variables were moderately correlated with prevalence (p<0.05), as were number of persons per room and TBM (total body minutes) with egg counts. In multivariate analysis, after controlling for demographic and socioeconomic factors, only total IgE levels were significantly correlated with both prevalence (p=0.248, 95% CI=1.01-1.11) and intensity (p=0.0217, 95% CI=0.01-0.14) of infection and eosinophil levels with prevalence (p=0.0005, 95% CI=1.07-1.24). Although any causal relationship cannot be confirmed by a cross-sectional study, we demonstrated an associated decrease in prevalence and intensity of S. mansoni infection with increased IgE levels.
    Acta tropica 09/2009; 113(1):34-41. DOI:10.1016/j.actatropica.2009.09.001 · 2.27 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: High quality multimedia streaming applications over the Internet require very low packet loss rates. The Internet is characterized by long bursts of packet losses and delays. A large receive buffer can be used to mitigate the effects of packet losses and delays. However, a large receive buffer introduces a large delay in the playback of a packet. This large delay could be annoying at the start of a program or during switch over to another channel in a multi-channel broadcast. We introduce a separate low-delay tuning stream to address this start-up problem. In the steady state, this tuning stream is synchronized appropriately with the high-delay steady state stream to give an enhanced composite signal
    Communications, 2001. ICC 2001. IEEE International Conference on; 02/2001
Show more