title: Surgical Elimination of the Gastric Digestion by Roux-en-Y Gastric Bypass Impacts on Food Sensitisation-a Pilot Study.
abstract: BACKGROUND
  Impairment of gastric digestion due to pH elevation increases the risk for food allergy induction. As patients after Roux-en-Y gastric bypass (RYGB) surgery have lower gastric acidity and less gastric gland secretion, we aimed to analyse in a prospective study the effect of limiting gastric digestion capacity by surgical intervention on the immune response towards allergens.
  
  
  METHODS
  Nine patients undergoing RYGB surgery for morbid obesity and one control patient having undergone surgery for treatment of an incisional hernia were enrolled in the study. Before and 1, 3, 6, 9 and 12 months after surgery, blood was collected for analysis of specific IgE antibodies, and patients were subjected to skin prick testing with 16 food and 18 aeroallergens.
  
  
  RESULTS
  Skin prick test results revealed an increase of positive reactions indicating sensitisations towards the tested food and aeroallergens in 77.8 and 88.9 % of the patients, respectively, after surgical elimination of gastric digestion. These results were in line with elevated titers of food- and aeroallergen-specific IgE antibodies in 7 out of 9 (7/9) and 5/9 patients, respectively, after RYGB surgery. Serum cytokine levels revealed a mixed response for IFN-γ and were mostly beneath detection limit for IL-4.
  
  
  CONCLUSIONS
  A change of IgE reactivity pattern occurred after impairment of gastric digestion due to surgical elimination underlining the important gastric gatekeeping function during oral sensitisation. Even though this study indicates an increased allergy risk for gastric bypass patients, further studies are needed to investigate in-depth the immunological changes associated with RYGB surgery.
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria. soheila.shakeri-manesch@meduniwien.ac.at.
authors.forename: Soheila
authors.initials: S
authors.lastname: Shakeri-Leidenmühler
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, E3Q, 1090, Vienna, Austria. anna.lukschal@meduniwien.ac.at.
authors.forename: Anna
authors.initials: A
authors.lastname: Lukschal
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, E3Q, 1090, Vienna, Austria. cornelia.schultz@meduniwien.ac.at.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Schultz
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria. office@drboh.at.
authors.forename: Arthur
authors.initials: A
authors.lastname: Bohdjalian
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria. felix.langer@meduniwien.ac.at.
authors.forename: Felix
authors.initials: F
authors.lastname: Langer
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria. office@dr-birsan.net.
authors.forename: Tudor
authors.initials: T
authors.lastname: Birsan
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, E3Q, 1090, Vienna, Austria. susanne.diesner@meduniwien.ac.at.|Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria. susanne.diesner@meduniwien.ac.at.
authors.forename: Susanne C
authors.initials: SC
authors.lastname: Diesner
authors.affiliation: Department of Dermatology, Division of Immunology, Allergy and Infectious Skin Diseases (DIAID), Medical University of Vienna, Vienna, Austria. elli.greisenegger@meduniwien.ac.at.
authors.forename: Elli K
authors.initials: EK
authors.lastname: Greisenegger
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, E3Q, 1090, Vienna, Austria. Otto.Scheiner@meduniwien.ac.at.
authors.forename: Otto
authors.initials: O
authors.lastname: Scheiner
authors.affiliation: Department of Dermatology, Division of Immunology, Allergy and Infectious Skin Diseases (DIAID), Medical University of Vienna, Vienna, Austria. tamara.kopp@meduniwien.ac.at.
authors.forename: Tamara
authors.initials: T
authors.lastname: Kopp
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, E3Q, 1090, Vienna, Austria. erika.jensen-jarolim@meduniwien.ac.at.|Comparative Medicine, Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University of Vienna and University of Vienna, Vienna, Austria. erika.jensen-jarolim@meduniwien.ac.at.
authors.forename: Erika
authors.initials: E
authors.lastname: Jensen-Jarolim
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria. gerhard.prager@meduniwien.ac.at.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Prager
authors.affiliation: Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, E3Q, 1090, Vienna, Austria. eva.untersmayr@meduniwien.ac.at.
authors.forename: Eva
authors.identifier: http://orcid.org/0000-0002-1963-499X
authors.initials: E
authors.lastname: Untersmayr
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004063:Digestion / Q000502:physiology*; D005260:Female; D005502:Food; D005512:Food Hypersensitivity / Q000209:etiology*; D015390:Gastric Bypass / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery*; D010865:Pilot Projects; D011446:Prospective Studies; D013270:Stomach / Q000503:physiopathology / Q000601:surgery*; D055815:Young Adult
keywords: Bariatric surgery; Food specific IgE; Laparoscopic gastric bypass; Sensitisation; Skin prick test