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| Author(s): |
Patricia Macchiaverni
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI) |
| Defense date: | 2008-08-12 |
| Examining board members: |
Antonio Condino Neto;
Sonia Jancar Negro;
Dirceu Solé
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| Advisor: | Antonio Condino Neto |
| Abstract | |
It is known that the incidence of allergic disease has been rising very fast in the last decade and nowadays affects thousands of children worldwide. For this reason, it is of great interest that efficient strategies of prevention of atopy should be applied in the first years of life or even before birth. The are strong evidences that the suppression of hypersensitivity in newborn can be mediated by the transference of maternal antibodies, depending on their concentration and specificity, however still little is known about the mechanisms involving, in special in humans. We made this study aiming to characterize qualitatively and quantitatively the antibodies transmission directed to the main home dust allergen (Dermatophagoides pteronyssinus; Der p) through placental transference and maternal breastfeeding as well as to investigate the maternal sensitizing effect against to Der p in passive transference of these antibodies. For those objectives, we quantified by ELISA, IgG anti-Der p in paired samples of maternal blood and umbilical cord and anti-Der p S-IgA in colostrums of sensitized mother (n=13) and not sensitized (n=26); and we analyzed the functional activity of the same antibodies by avidity assays. The sensibility was determined in maternal sera by specific RAST (Cap System® Pharmacia). We show by the first time that anti-Der p S-IgA is transferred to the infant in very variable concentrations and with high levels of avidity, but is not dependent of maternal sensitization. We believe that breastfeeding is important, because it supplies S-IgA with the capacity to neutralize in a specific manner and block the entrance of Der p through mucosa, in infant of RAST+ mothers as well as of RAST-. We also demonstrate that total and specific to Der p IgG levels are more elevated in newborns of sensitized mothers when compared to of those of control mothers and non-sensitized indicating that the maternal sensitizing can influence the fetal immune response. In the other hand, the specific avidity of anti-Der p IgG was very similar between paired samples of umbilical cord and maternal sera, as well as in samples of study group and control group, suggesting thar the avidity index of IgG does not influence on placental transfer of specific antibodies. Once that the maternal antibody transference represent a important mechanism for immunomodulation of allergic response, we expect that a better understanding of the influence of maternal sensitivity on passive transfer of specific antibodies to babies will contribute with advances in the elaboration of adequate strategies of prevention of allergic sensitivity with more efficient therapeutic results. (AU) | |