R De Bruyne1, P Gevaert2, M Van Winckel1, N De Ruyck2, A Minne3, D Bogaert3,4, S Van Biervliet1, S Vande Velde1, F Smets5, E Sokal5, F Gottrand6, J Vanhelst7, B Detry8,9, C Pilette8,9, B N Lambrecht4,10,11, M Dullaers4. 1. Department of Pediatric Gastroenterology, Hepatology and Nutrition, Princess Elisabeth Children's Hospital, Ghent University Hospital, Ghent, Belgium. 2. Upper Airways Research Laboratory, Department of Otorhinolaryngology, Ghent University Hospital, Ghent, Belgium. 3. Department of Pediatrics, Princess Elisabeth Children's Hospital, Ghent University Hospital, Ghent, Belgium. 4. Clinical Immunology Research Laboratory, Department of Respiratory Medicine, Ghent University Hospital, Ghent, Belgium. 5. Service de Gastro-entérologie et Hépatologie Pédiatrique et Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium. 6. Inserm U995, Faculty of Medicine, CIC-PT-9301, Department of Pediatric Gastroenterology, Hepatology and Nutrition, Hospital Jeanne de Flandre, CHRU Lille, University Lille2, Lille, France. 7. Centre d'Investigation Clinique de Lille-PT-1403-Inserm-CH&U, Inserm U995, Faculty of Medicine, University Lille2, Lille, France. 8. Pole of Pneumology, ENT and Dermatology, Institute of Experimental and Clinical Research, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium. 9. Walloon Excellence in Lifesciences and Biotechnology (WELBIO) Institute, Brussels, Belgium. 10. Laboratory of Immunoregulation, VIB Inflammation Research Center, Ghent, Belgium. 11. Department of Pulmonary Medicine, Erasmus MC, Rotterdam, The Netherlands.
Abstract
BACKGROUND: Post-transplant food allergy (LTFA) is increasingly observed after paediatric liver transplantation (LT). Although the immunopathology of LTFA remains unclear, immunoglobulin (Ig) E seems to be implicated. OBJECTIVE: To study humoral and cellular immunity in paediatric LT patients in search for factors associated with LTFA, and compare with healthy controls (HC) and non-transplant food-allergic children (FA). METHODS: We studied serum Ig levels in 29 LTFA, 43 non-food-allergic LT patients (LTnoFA), 21 FA patients and 36 HC. Serum-specific IgA and IgE against common food allergens in LTFA, IgA1 , IgA2 and joining-chain-containing polymeric IgA (pIgA) were measured. Peripheral blood mononuclear cells were analysed by flow cytometry for B and T cell populations of interest. RESULTS: Serum IgA and specific IgA were higher in LTFA compared to LTnoFA. LTFA patients had the highest proportion of circulating T follicular helper cells (cTfh). The percentage of cTfh correlated positively with serum IgA. Unique in LTFA was also the significant increase in serum markers of mucosal IgA and the decrease in the Th17 subset of CXCR5(-) CD4(+) cells compared to HC. Both LT patients exhibited a rise in IgA(+) memory B cells and plasmablasts compared to HC and FA. CONCLUSIONS: LT has an impact on humoral immunity, remarkably in those patients developing FA. The increase in serum markers of mucosal IgA, food allergen-specific IgA and cTfh cells observed in LTFA, point towards a disturbance in intestinal immune homoeostasis in this patient group.
BACKGROUND: Post-transplant food allergy (LTFA) is increasingly observed after paediatric liver transplantation (LT). Although the immunopathology of LTFA remains unclear, immunoglobulin (Ig) E seems to be implicated. OBJECTIVE: To study humoral and cellular immunity in paediatric LT patients in search for factors associated with LTFA, and compare with healthy controls (HC) and non-transplant food-allergicchildren (FA). METHODS: We studied serum Ig levels in 29 LTFA, 43 non-food-allergic LTpatients (LTnoFA), 21 FA patients and 36 HC. Serum-specific IgA and IgE against common food allergens in LTFA, IgA1 , IgA2 and joining-chain-containing polymeric IgA (pIgA) were measured. Peripheral blood mononuclear cells were analysed by flow cytometry for B and T cell populations of interest. RESULTS: Serum IgA and specific IgA were higher in LTFA compared to LTnoFA. LTFA patients had the highest proportion of circulating T follicular helper cells (cTfh). The percentage of cTfh correlated positively with serum IgA. Unique in LTFA was also the significant increase in serum markers of mucosal IgA and the decrease in the Th17 subset of CXCR5(-) CD4(+) cells compared to HC. Both LT patients exhibited a rise in IgA(+) memory B cells and plasmablasts compared to HC and FA. CONCLUSIONS: LT has an impact on humoral immunity, remarkably in those patients developing FA. The increase in serum markers of mucosal IgA, food allergen-specific IgA and cTfh cells observed in LTFA, point towards a disturbance in intestinal immune homoeostasis in this patient group.