Comparative study of eosinophil chemotaxis, adhesion, and degranulation in vitro in ulcerative colitis and Crohn's disease.
BACKGROUND
Eosinophils have been identified in tissues from patients with Crohn's disease (CD) and ulcerative colitis (UC) but whether they contribute to IBD pathogenesis is unknown. This study aimed to investigate the functional activity and morphological aspects of peripheral-blood eosinophils from IBD patients compared to those from healthy volunteers (HVs).


METHODS
Eosinophils from HVs and CD and UC patients were purified using a Percoll gradient and then a immunomagnetic cell separator. Functional activity in inactivated and previously activated cells was investigated by measuring adhesion to fibronectin and chemotaxis to fMLP, and degranulation was measured by release of eosinophil peroxidase (EPO). Cell morphology was investigated using electron microscopy.


RESULTS
Eosinophil adhesion to human fibronectin in both inactivated and PAF-stimulated and PMA-stimulated eosinophils was markedly higher in patients with CD than in either patients with UC or HVs. Similarly, the chemotactic response was markedly higher in eosinophils isolated from CD patients than in those isolated from UC patients or HVs. Baseline EPO release was higher in eosinophils isolated from UC patients than in those isolated from HVs or CD patients. Stimulation with fMLP or PMA did not further increase EPO release in cells from UC or CD patients. Comparable expression of MAC- 1 and VLA-4 adhesion molecules was observed on the surfaces of eosinophils from all groups, and an greater number of granules was noted in the eosinophils from UC patients than in those from CD patients.


CONCLUSIONS
Our results indicate that peripheral-blood eosinophils are potentially primed and activated in IBD patients. Whether the differences in the morphology and functional responses of eosinophil from UC and CD patients reflect differences in disease phenotype remains to be elucidated.
Coppi
Luciane C
LC
GI Research Laboratory-Gastrocentro, Department of Internal Medicine, Faculty of Medical Sciences, University of Campinas, Campinas, SP, Brazil.
Thomazzi
Sara M
SM
de Ayrizono
Maria Lourdes S
ML
Coy
Claudio S R
CS
Fagundes
W Joao J
WJ
Goes
Juvenal R N
JR
Franchi
Gilberto C
GC
Nowill
Alexandre E
AE
Montes
Ciro G
CG
Antunes
Edson
E
Ferraz
Jose Geraldo P
JG
D002448:Cell Adhesion; D015550:Cell Degranulation; D002633:Chemotaxis; D003093:Colitis, Ulcerative / Q000473:pathology / Q000503:physiopathology*; D003424:Crohn Disease / Q000473:pathology / Q000503:physiopathology*; D047209:Eosinophil Peroxidase / Q000378:metabolism; D004804:Eosinophils / Q000473:pathology / Q000502:physiology*; D005260:Female; D005353:Fibronectins; D006801:Humans; D007155:Immunologic Factors / Q000378:metabolism; D066298:In Vitro Techniques; D039041:Integrin alpha4beta1 / Q000378:metabolism; D016177:Macrophage-1 Antigen / Q000378:metabolism; D008297:Male; D008854:Microscopy, Electron
D005353:Fibronectins; D007155:Immunologic Factors; D039041:Integrin alpha4beta1; D016177:Macrophage-1 Antigen; D047209:Eosinophil Peroxidase