Functional and morphologic characterization of eosinophils in the lower intestinal mucosa of patients with food allergy.
OBJECTIVE
The aim of this study was to characterize the functional and morphologic features of eosinophils in the intestinal mucosa of patients with food allergy.


METHODS
Eighteen patients with food allergy and 11 controls took part in this study. In every patient, corresponding biopsy samples obtained during colonoscopy were quantitatively assessed by immunohistochemical methods (EPO-I) and subjected to mucosa oxygenation using eosinophilic cationic protein (ECP). Initial basal release, spontaneous and anti-IgE-dependent release, and the total ECP content of mucosal biopsies were studied.


RESULTS
Morphologically, mucosal eosinophils in patients with food allergy have distinct features, occur in larger amounts, and show a distinct distribution pattern (i.e., intraepithelial, lamina propria, and submucosa). Their initial basal release is similar to that of controls, but stimulation of the IgE receptor with anti-IgE results in 40-fold activation (p < 0.001). In food allergy patients, the density of eosinophils, the presence of intraepithelial eosinophils, and the rate of degranulation showed a highly significant correlation to the initial basal release of ECP by mucosal tissue (Kendall tau = 0.619, 0.381, and 0.609, respectively; p < 0.05 for all) but not to their capability to be stimulated with anti-IgE.


CONCLUSIONS
Eosinophils of the lower intestine of patients with food allergy show characteristic features with regard to morphology, distribution, and functional behavior to IgE receptor stimulation. Immunostaining of eosinophil peroxidase (EPO) detects important characteristic features that are missed with conventional hematoxylin-eosin staining.
Schwab
Dieter
D
Department of Medicine 1, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
Müller
Susanna
S
Aigner
Thomas
T
Neureiter
Daniel
D
Kirchner
Thomas
T
Hahn
Eckhart G
EG
Raithel
Martin
M
D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000494:pharmacology; D001706:Biopsy; D001798:Blood Proteins / Q000378:metabolism; D015550:Cell Degranulation; D004311:Double-Blind Method; D016099:Endoscopy, Gastrointestinal; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D005512:Food Hypersensitivity / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D017455:Receptors, IgE / Q000187:drug effects / Q000378:metabolism; D012260:Ribonucleases
D000888:Antibodies, Anti-Idiotypic; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D017455:Receptors, IgE; D007073:Immunoglobulin E; D012260:Ribonucleases