Table 1.

Studies that investigated T-cell responses in food protein-induced enterocolitis syndrome and non-IgE-mediated food allergy

Study	Findings
Van Sickle et al. [32]	In children with confirmed FPIES, peripheral blood mononuclear cell (PBMC) stimulation by the causal antigen induced greater cell proliferation than in children with negative oral food challenge
Hoffman et al. [33]	Higher lymphocyte proliferative response in affected children was observed, but the stimulation index was not significantly different compared with the control group
Heyman et al. [34]	The high level of TNF-α released by antigen-specific T cells acts synergistically with IFN-γ to increase intestinal permeability. This may contribute to the influx of antigens into the submucosa with further activation of antigen-specific T cells
Benlounes et al. [35]	Intact rather than intestinally processed proteins stimulate PBMC to release TNF-α. The threshold for PBMC reactivity to milk antigens decreases considerably during active cow's milk allergy with intestinal symptoms compared with patients whose sensitivity resolved or with those with skin rather than intestinal manifestation of cow's milk hypersensitivity. In-vitro kinetic studies differed in these groups, with those having active disease showing two peaks in TNF-α elaboration. The second peak occurred after 5 days of culture
Chung et al. [36]	There was higher staining for TNF-α in infants with FPIES and with villous atrophy compared with those without villous atrophy, and with the control group. Type 1, but not type 2, receptor for TGF-β was decreased in duodenal biopsy specimens in FPIES patients compared with controls
Mori et al. [37]	In a case of FPIES to rice, authors described an increase in IL-4 and decrease in IFN-γ expression in T cells after a positive oral challenge with rice. After the patient had acquired tolerance, there was an increase in IL-10 expression in CD3+ cells, as well as an increase in IFN-γ before and after the challenge
Karlsson et al. [38]	Children outgrowing non-IgE-mediated hypersensitivity to cow's milk following a period of dairy-free diet were compared to children with active non-IgE-mediated hypersensitivity to cow's milk protein. The results revealed a higher frequency of circulating CD4+CD25+ Treg cells specific for cow's milk protein in children outgrowing non-IgE-mediated hypersensitivity to cow's milk protein. The suppressive action of cow's milk-specific Treg cells was exerted partly by direct cell–cell contact and partly by production of TGF-β