Published online: February 10, 2017
Food protein Induced Enterocolitis Syndrome (FPIES) is a non-IgE-mediated food allergy. Young children react to foods such as milk, soy, or rice with severe repetitive vomiting and shock-like symptoms within a few hours of ingestion. Although FPIES has been proposed to be a cell-mediated allergy, there is little information on the mechanism responsible for these severe systemic reactions.
In a recently published article in The Journal of Allergy and Clinical Immunology (JACI), Goswami and colleagues used advanced profiling approaches including CyTOF mass cytometry and RNA sequencing to study cells in whole blood in patients undergoing food challenges for the clinical management of FPIES. The immune response of those who tolerated the food challenge without symptoms, and had therefore outgrown their FPIES, was compared to those who had adverse reactions to the challenge.
The researchers found evidence of systemic innate immune activation only in those who reacted to food challenge. Of all the cell types present in circulation, monocytes were the cells with the most marked activation after a positive food challenge. Neutrophils were also increased in number as well as activation status, and NK cells and eosinophils also showed evidence of activation. Despite a lack of antigen-specific lymphocyte activation in FPIES, there was a global activation of lymphocytes and loss from the circulation.
The key role of monocytes and other innate immune cells in FPIES provide novel pathways to consider for the development of therapeutics. The mechanism of food recognition by the innate immune system, in the absence of detectable specific T cell or antibody responses, remains an intriguing question.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.