Eosinophil infiltration and degranulation in oesophageal mucosa from adult patients with eosinophilic oesophagitis: a retrospective and comparative study on pathological biopsy.
OBJECTIVE
To examine eosinophil infiltration and degranulation in 50 oesophageal biopsy specimens from 30 patients (21 men, 9 women; mean 39 years) with eosinophilic oesophagitis, by haematoxylin and eosin staining and immunohistochemistry.


METHODS
Immunohistochemistry was carried out using a monoclonal antibody for human eosinophilic major basic protein (MBP). Eosinophils were counted in three high power fields (x40) and degranulation, as quantified by extracellular MBP immunostaining, was scored on a scale of 1-4. Morphological changes (basal cell hyperplasia, elongation of papillae and dilatation of intercellular spaces) were scored on a 1-4 scale on sections stained with haematoxylin and eosin.


RESULTS
Numbers of intraepithelial eosinophils were significantly higher with MBP immunostaining than with haematoxylin and eosin staining (mean 109.6 v 80.6; p<0.001), whereas numbers of eosinophils were considerably correlated (r = 0.794). Eosinophil degranulation was higher in the distal oesophagus. Additionally, basic morphological changes were markedly associated with eosinophil infiltration. Extracellular deposition of eosinophil-MBP and eosinophil infiltration in subepithelial connective tissue, present in the biopsy specimens, were detected by immunohistochemistry.


CONCLUSIONS
Numbers of eosinophils and degranulation are underestimated by haematoxylin and eosin staining. Immunohistochemistry detected up to two times more eosinophils than routine haematoxylin and eosin staining. Moreover, eosinophil-MBP immunoreactivity in extracellular regions indicates the release of toxic eosinophil granule proteins and gives further evidence for a causative role of eosinophils with regard to structural changes in eosinophilic oesophagitis. Immunohistochemistry may serve as a useful diagnostic tool to support the morphological differential diagnosis of eosinophilic oesophagitis and gastro-oesophageal reflux disease.
Institute of Pathology, Klinikum Bayreuth, Bayreuth, Germany. susanna@t-online.de
S
S
Mueller
T
T
Aigner
D
D
Neureiter
M
M
Stolte
D000328:Adult; D000368:Aged; D001706:Biopsy; D015550:Cell Degranulation; D047093:Eosinophil Major Basic Protein / Q000378:metabolism; D004802:Eosinophilia / Q000378:metabolism / Q000473:pathology*; D004804:Eosinophils / Q000502:physiology*; D004847:Epithelial Cells / Q000473:pathology; D004941:Esophagitis / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D012189:Retrospective Studies
D047093:Eosinophil Major Basic Protein