title: Basophil infiltration in eosinophilic oesophagitis and proton pump inhibitor-responsive oesophageal eosinophilia.
abstract: BACKGROUND
  The features of proton pump inhibitor-responsive oesophageal eosinophilia (PPI-REE) are similar to those of eosinophilic oesophagitis (EoE), but PPI-REE demonstrates symptomatic and histological responses to PPI therapy. Several studies have shown that basophils play a crucial role in the pathogenesis of allergic diseases.
  
  
  OBJECTIVE
  To identify and compare basophil infiltration in the oesophageal epithelium in patients with EoE, PPI-REE, gastroesophageal reflux disease (GERD) and normal oesophagus (controls).
  
  
  METHODS
  Biopsy specimens from 43 patients, including 12 with EoE, 11 with PPI-REE, 10 with GERD and 10 normal oesophagus, were analysed. Immunohistochemistry was performed to quantify the number of basophils and mast cells in the oesophageal epithelium. Double immunofluorescence staining for thymic stromal lymphopoietin (TSLP) and basophils was performed. Patients with EoE were treated with swallowed fluticasone.
  
  
  RESULTS
  There were no differences in clinical, endoscopic or histological features between patients with EoE and PPI-REE. There were more basophils and mast cells in patients with EoE and PPI-REE than in patients with GERD and control subjects. Basophil infiltration of the oesophageal epithelium in patients with EoE was higher than that in patients with PPI-REE (3.6 ± 2.8 per high power field vs. 1.2 ± 0.9 per high power field respectively; P = 0.02); however, there was no significant difference in mast cell infiltration between the two groups. TSLP was highly expressed in the oesophageal epithelium in areas infiltrated by basophils. Steroid therapy significantly decreased intraepithelial basophils in patients with EoE.
  
  
  CONCLUSIONS
  Basophils may play an important role in the pathogenesis of eosinophilic oesophagitis.
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Iwakura
authors.forename: Y
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: F
authors.initials: F
authors.lastname: Tanaka
authors.forename: T
authors.initials: T
authors.lastname: Tanigawa
authors.forename: H
authors.initials: H
authors.lastname: Yamagami
authors.forename: M
authors.initials: M
authors.lastname: Shiba
authors.forename: K
authors.initials: K
authors.lastname: Tominaga
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: K
authors.initials: K
authors.lastname: Iijima
authors.forename: T
authors.initials: T
authors.lastname: Koike
authors.forename: A F
authors.initials: AF
authors.lastname: Walls
authors.forename: T
authors.initials: T
authors.lastname: Arakawa
mesh_terms: D000328:Adult; D000368:Aged; D001491:Basophils / Q000378:metabolism*; D004802:Eosinophilia / Q000188:drug therapy* / Q000503:physiopathology*; D057765:Eosinophilic Esophagitis / Q000503:physiopathology*; D004945:Esophagoscopy; D004947:Esophagus / Q000378:metabolism; D005260:Female; D005764:Gastroesophageal Reflux / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000494:pharmacology*
chemical_list: D054328:Proton Pump Inhibitors