P140. Serum concentrations of insulin-like growth factor-binding protein 5 in Crohn's disease
G. Adali, E. Yorulmaz, S. Ozkanli, C. Ulasoglu, B. Bayraktar, A. Orhun, Y. Colak, I. Tuncer, Goztepe Training and Research Hospital, Department of Gastroenterology, Istanbul, Turkey
The factors underlying stricture development in CD are not completely understood. It is critical to develop markers that can be used to predict intestinal stricture formation in the early stages of CD. The insulin-like growth factor (IGF) system has a critical role in regulating the growth and development of visceral and vascular smooth muscle. To investigate serum insulin-like growth factor-binding protein 5 (IGFBP-5) levels and intestinal IGFBP-5 expression in patients with Crohn's disease (CD).
We analyzed the serum concentrations and intestinal expression of IGFBP-5 in 42 patients with CD, of whom 26 had endoscopically or radiologically proven stricture formation. Nine of the 42 patients had active disease, with a Crohn's disease activity index (CDAI) >150. Serum IGFBP-5 levels were analyzed in 20 healthy controls matched by sex and age to the CD patients. Serum IGFBP-5 was measured using an enzyme-linked immunosorbent assay. Intestinal tissue was obtained from patients through endoscopic biopsies. IGFBP-5 expression was detected using immunohistochemistry and was scored semiquantitatively.
The median serum IGFBP-5 concentrations of CD patients were significantly lower compared with healthy controls [median 7.2 (IQR: 5.5–11.3) ng/mL vs. 11.3 (8.0–44.6) ng/mL, P < 0.001]. There was no significant difference between median serum IGFBP-5 levels in CD patients with or without stricture formation [6.9 (5.5–11.3) ng/mL vs. 7.8 (5.3–10.1) ng/mL; P = 0.815]. The serum IGFBP-5 levels were not significantly different between patients with active disease and inactive disease [7.2 (6.5–7.6). ng/mL vs. 7.2 (5.5–11.3) ng/mL; P = 0.890]. No significant correlation was found between tissue IGFBP-5 immunohistochemical staining intensity scores and serum IGFBP-5 levels. No significant difference was found when comparing the serum IGFBP-5 levels among the patients with different tissue IGFBP-5 staining scores (absent/very weak, weak, moderate or strong).
Our results indicate that serum IGFBP-5 concentrations were lower in CD patients compared to healthy controls regardless of disease activity or the presence of stricture formation. Serum IGFBP-5 concentrations were not associated with intestinal IGFBP-5 tissue expression. Therefore, our results do not answer the question of whether IGFBP-5 is involved in the stricture formation of CD, and thus, more research is necessary.