DISTINCT CYTOKINE PATTERNS IN EARLY AND CHRONIC ILEAL LESIONS OF CROHNS-DISEASE

Background & Aims: Chronic intestinal lesions of patients with Crohn's disease (CD) are associated with a T helper (Th) 1-type cytokine prof ile, including high levels of interleukin 2 (IL-2) and interferon gamm a (IFN-gamma). However, the mechanisms involved in the pathogenesis of the early mucosal lesions are poorly known. The aim of this study was to examine the pattern of Th1- and Th2-type (IL-4, IL-5, and IL-13) c ytokines in the early ileal lesions occurring in patients with CD 3 mo nths after ileal resection and ileocolonic anastomosis. Cytokines were also examined in the chronic ileal lesions to look for cytokine patte rns related to disease progression. Methods: Ileal biopsy specimens we re obtained from 17 patients with CD and 11 controls. Mucosal IL-2, IF N-gamma, IL-4, IL-5, and IL-13 messenger RNA (mRNA) was evaluated by c ompetitive reverse-transcription polymerase chain reaction. Results: T he early ileal lesions of patients with CD were associated with a sign ificant increase of IL-4 mRNA and a decrease of IFN-gamma mRNA compare d with the normal mucosa of patients with CD or controls. A Th1-type p attern was observed in the chronic ileal lesions, Conclusions: Diverge nt cytokine patterns are observed during different clinical stages of CD. These observations need to be considered in the development of new er specific therapeutic agents to prevent CD recurrences.