Immunohistochemical study of intestinal eosinophils in inflammatory bowel disease.
BACKGROUND
Eosinophil accumulation and activation are characteristic features of inflammation in allergic diseases and in host defense against parasites.


OBJECTIVE
To investigate the involvement of eosinophils in inflamed and noninflamed mucosa of patients with inflammatory bowel disease (IBD).


METHODS
Specimens of inflamed colonic mucosa from 15 patients with ulcerative colitis (UC) and inflamed and noninflamed colonic mucosa from 15 patients with Crohn's disease (CD) were submitted to histologic and immunohistochemical studies. Twelve patients with irritable bowel syndrome were studied as controls. Sirius red was used to label eosinophils in tissue. EG1, EG2, and anti-hIL-5 were used as primary antibodies in an indirect alkaline phosphatase-labeled immunostaining protocol. Both positive and negative lamina propria cells were assessed by a quantitative grading system and the results expressed as cell numbers per mm.


RESULTS
Increased proportions of eosinophils stained with Sirius red, EG1, EG2, and anti-hIL-5+ cells were found in the colon of patients with UC and in inflamed and noninflamed colon of CD patients as compared with controls. Crohn's disease patients showed increased proportions of EG1+ and EG2+ cells as compared with those with UC. Increased proportions of IL-5+ cells were detected in UC patients as compared with those with CD.


CONCLUSIONS
Quantitative eosinophil alterations and IL-5+ cells may indicate enhanced cellular activation with degranulation, which is implicated in the pathogenesis of IBD. Increase in IL-5+ cells may reflect a predominant local Th2 response in UC as compared with CD.
Carvalho
Ana Teresa Pugas
AT
Department of Internal Medicine, School of Medicine, Multidisciplinary Laboratory of the University Hospital, Federal University of Rio de Janeiro, Brazil. pugas@openlink.com.br
Elia
Celeste Carvalho Siqueira
CC
de Souza
Heitor Siffert Pereira
HS
Elias
Paulo Roberto Pinheiro
PR
Pontes
Eduardo Lopes
EL
Lukashok
Hannah Pitanga
HP
de Freitas
Fernanda Cristina Dias
FC
Lapa e Silva
José Roberto
JR
D000293:Adolescent; D000328:Adult; D000368:Aged; D001391:Azo Compounds; D001798:Blood Proteins / Q000378:metabolism; D003092:Colitis / Q000378:metabolism; D003093:Colitis, Ulcerative / Q000378:metabolism; D003424:Crohn Disease / Q000378:metabolism; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000378:metabolism*; D005260:Female; D006801:Humans; D007079:Ileitis / Q000378:metabolism; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000453:epidemiology / Q000378:metabolism*; D015848:Interleukin-5 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology* / Q000378:metabolism*; D008297:Male; D056892:Mediator Complex; D008875:Middle Aged; D011446:Prospective Studies; D011506:Proteins / Q000378:metabolism; D012260:Ribonucleases
D001391:Azo Compounds; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D015848:Interleukin-5; C496877:MED28 protein, human; D056892:Mediator Complex; D011506:Proteins; C062246:Direct Red 81; D012260:Ribonucleases