Background: Mucosal lesions of pouchitis are characterized by a neutrophil
infiltrate. Interleukin (IL)-8 is the main mediator involved in neutrophil
recruitment and is downregulated by IL-10. Aim: To look for an imbalance be
tween IL-8 and IL-10 in patients with pouchitis. Patients/Methods: 18 patie
nts having an ileoanal pouch for ulcerative colitis were studied. Eleven ha
d pouchitis defined by the pouchitis disease activity index of greater than
or equal to 7 points and 7 had no history of pouchitis. Biopsies taken at
the site of inflammation or in the normal mucosa were scored for the histol
ogic lesions, the intensity of neutrophil infiltration, and the presence of
crypt abscesses. Mucosal IL-8 and IL-10 mRNA were quantified by competitiv
e polymerase chain reaction. Results: IL-8, IL-10, and IL-10/IL-8 mRNA were
similar in patients with or without pouchitis. IL-8 mRNA levels were signi
ficantly higher in patients with a histologic score >2 (p = 0.01) and in pa
tients with crypt abscesses (p = 0.01). IL-10/IL-8 mRNA was significantly l
ower in patients having a histologic score >2 (p = 0.019), a neutrophil inf
iltration greater than or equal to 10% (p = 0.013), and crypt abscesses (p
= 0.01). Conclusion: Histologic lesions of pouchitis are associated with a
mucosal imbalance between IL-8 and IL-10. IL-10 could be proposed as a new
treatment for pouchitis.