Dynamics of cytokine mRNA expression and fecal biomarkers in school-children undergoing a double-blind placebo-controlled food challenge series
(English)Manuscript (preprint) (Other academic)
Background There is a need for novel objective prognostic markers for symptomatic food allergy, since current diagnostic methods are insufficient and/or time and labor consuming.
Objective To estimate the cytokine mRNA profiles in peripheral blood mononuclear cells (PBMC) before and after a double-blind placebo-controlled food challenge series in schoolchildren with suspected allergy to milk, egg or cod and in healthy controls. Analyses of fecal inflammatory biomarkers before and after challenge were included.
Methods Twelve-year-old children from a population-based cohort reporting complete avoidance of milk, egg, cod or wheat due to perceived hypersensitivity were clinically examined and those with suspected food allergy were evaluated with a 3-session double-blind placebo-controlled food challenge. In addition, 7 healthy controls from the same cohort participated in a double-blind challenge series with egg. Before and after the challenge series, blood samples were collected for analyses of cytokine mRNA expression, quantified for a panel of 15 cytokines discriminating between a humoral Th2-, cytotoxic Th1-, regulatory Th3/Tr1- and inflammatory responses. Stool samples for analyses of calprotectin and eosinophil-derived neurotoxin, were also collected from children with suspected food allergy. The test results were analyzed in relation to challenge outcome.
Results Pre challenge, suspected food allergic children had elevated expression levels of the Th2-associated cytokine IL-13 compared to controls. IL-13 mRNA and mRNA for the regulatory cytokine IL-10 were higher in challenge-proven food allergy compared to the cytokine levels seen in negative challenges. Post challenge, IL-1β and IL-6 mRNA were elevated in the allergic children compared to controls. Fecal calprotectin and EDN levels were higher in challenge proven food allergy compared to a negative challenge although not statistically significantly.
Conclusion & Clinical relevance The spontaneous cytokine mRNA expression differed between children with suspected food allergy and controls both pre and post challenge. Some of the analyzed biomarkers in blood and feces might serve as future prognostic markers for symptomatic, IgE-mediated food allergy but need further validation.
cytokines, fecal biomarkers, food allergy, children
Pediatrics Immunology in the medical area
IdentifiersURN: urn:nbn:se:umu:diva-114048OAI: oai:DiVA.org:umu-114048DiVA: diva2:892562