7 research outputs found
Extensively Hydrolyzed Hypoallergenic Infant Formula with Retained T Cell Reactivity
Background: Immunoglobulin E (IgE)-mediated cowâs milk allergy (CMA) can be life-threatening and affects up to 3% of children. Hypoallergenic infant formulas based on hydrolyzed cowâs milk protein are increasingly considered for therapy and prevention of cowâs milk allergy. The aim of this study was to investigate the allergenic activity and ability to induce T cell and cytokine responses of an infant formula based on extensively hydrolyzed cowâs milk protein (whey) (eHF, extensively hydrolyzed formula) supplemented with Galactooligosaccharides (GOS) and Limosilactobacillus fermentum CECT5716 (LF) to determine its suitability for treatment and prevention of CMA. Methods: eHF and standard protein formula based on intact cowâs milk proteins (iPF) with or without Galactooligosaccharide (GOS) and Limosilactobacillus fermentum CECT5716 (LF) were investigated with allergen-specific antibodies and tested for IgE reactivity and allergenic activity in basophil degranulation assays with sera from cowâs milk (CM)-allergic infants/children. Their ability to stimulate T cell proliferation and cytokine secretion in cultured peripheral blood mononuclear cells (PBMC) from CM-allergic infants and children was studied with a FACS-based carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution assay and xMAP Luminex fluorescent bead-based technology, respectively. Results: An eHF supplemented with GOS and LF exhibiting almost no IgE reactivity and allergenic activity was identified. This eHF induced significantly lower inflammatory cytokine secretion as compared to an intact protein-based infant formula but retained T cell reactivity. Conclusions: Due to strongly reduced allergenic activity and induction of inflammatory cytokine secretion but retained T cell reactivity, the identified eHF may be used for treatment and prevention of CMA by induction of specific T cell tolerance
Transfer and loss of allergenâspecific responses via stem cell transplantation: A prospective observational study
Background
Currently, no estimates can be made on the impact of hematopoietic stem cell transplantation on allergy transfer or cure of the disease. By using componentâresolved diagnosis, we prospectively investigated 50 donorârecipient pairs undergoing allogeneic stem cell transplantation. This allowed calculating the rate of transfer or maintenance of allergenâspecific responses in the context of stem cell transplantation.
Methods
Allergenâspecific IgE and IgG to 156 allergens was measured pretransplantation in 50 donors and recipients and at 6, 12 and 24 months in recipients postâtransplantation by allergen microarray. Based on a mixed effects model, we determined risks of transfer of allergenâspecific IgE or IgG responses 24 months postâtransplantation.
Results
After undergoing stem cell transplantation, 94% of allergenâspecific IgE responses were lost. Two years postâtransplantation, recipients' allergenâspecific IgE was significantly linked to the pretransplantation donor or recipient status. The estimated risk to transfer and maintain individual IgE responses to allergens by stem cell transplantation was 1.7% and 2.3%, respectively. Allergenâspecific IgG, which served as a surrogate marker of maintaining protective IgG responses, was highly associated with the donor's (31.6%) or the recipient's (28%) pretransplantation response.
Conclusion
Hematopoietic stem cell transplantation profoundly reduces allergenâspecific IgE responses but also comes with a considerable risk to transfer allergenâspecific immune responses. These findings facilitate clinical decisionâmaking regarding allergic diseases in the context of hematopoietic stem cell transplantation. In addition, it provides prospective data to estimate the risk of transmitting allergenâspecific responses via hematopoietic stem cell transplantation