Cytokine profile of food‐allergic post‐liver transplant children is identified by high levels of IL‐5 and low IL‐10 secretion from patients' peripheral blood mononuclear cells

Severe allergic reaction to food following liver transplantation is a well‐known phenomenon. However, the mechanisms underlying this phenomenon are not yet elucidated. This study aimed to reveal the nature of the immune response in post‐transplanted allergic patients and compare them to non‐allergic transplanted as well as allergic and non‐allergic control subjects, with focus on cytokine milieu. Post‐liver transplant patients with and without allergic reactions as well as food‐allergic but otherwise healthy and healthy non‐allergic control patients were recruited. We reviewed patient records and routine laboratory tests and assayed subjects' PBMCs, studying cytokine secretion profile in response to different stimuli. Post‐transplant patients with food allergy showed a unique cytokine profile in response to various stimuli, with extremely elevated IL‐5, low IL‐10 secretion, and somewhat higher IFN‐γ. T regulatory cell number was not significantly different among the groups of patients and controls. Immune response of food‐allergic post‐liver transplant patients is identified by a unique cytokine profile when compared to allergic but otherwise healthy individuals.     

Selective expansion of donor‐derived regulatory T cells after allogeneic bone marrow transplantation in a patient with IPEX syndrome

IPEX syndrome is a rare and fatal disorder caused by absence of regulatory T cells (Tregs) due to congenital mutations in the Forkhead box protein 3 gene. Here, we report a patient with IPEX syndrome treated with RIC followed by allogeneic BMT from an HLA‐matched sibling donor. We could achieve engraftment and regimen‐related toxicity was well tolerated. Although the patient was in mixed chimera and the ratio of donor cells in whole peripheral blood remained relatively low, selective and sustained expansion of Tregs determined as CD4+CD25+Foxp3+ cells was observed. Improvement in clinical symptoms was correlated with expansion of donor‐derived Tregs and disappearance of anti‐villin autoantibody, which was involved in the pathogenesis of gastrointestinal symptoms in IPEX syndrome. This clinical observation suggests that donor‐derived Tregs have selective growth advantage in patients with IPEX syndrome even in mixed chimera after allogeneic BMT and contribute to the control of clinical symptoms caused by the defect of Tregs.