P084 Effect of infliximab on monocyte subtypes in blood of patients with chronic inflammatory bowel...

Basic Science S43

at an increased risk of developing CD as a consequence of animpaired ability to handle enteric bacterial pathogens.

Reference(s)[1] Segal & Loewi, (1976), Lancet, Jul 31; 2(7979): 219 21.[2] Smith AM et al, (2009), JEM, 1883 97.

P084Effect of infliximab on monocyte subtypes in blood ofpatients with chronic inflammatory bowel disease

S. Slevin1 *, C. Dennedy1, M. Griffin1, L. Egan2. 1NationalUniversity of Ireland, Galway, REMEDI, Galway, Ireland,2National University of Ireland, Galway, Department ofPharmacology and Therapeutics, Galway, Ireland

Background: Monocytes are multi-functional myeloid cellswith roles in homeostasis, tissue repair and they also play adominant part in the link between the innate and adaptiveimmune system. Monocytes are believed to be involved inthe pathogenesis of chronic inflammatory disorders such asinflammatory bowel disease (IBD) and drugs active against IBDmay exert their benefits at least in part through actions onmonocytes. A new monocyte classification has been proposedthat uses CD14 and CD16 expression as determined byflow cytometry to define three functionally distinct classes:CD14++ CD16 (classical), CD14++ CD16+ (intermediate) andCD14+ CD16++ (non-classical). To date, little is known aboutthese monocyte subsets in IBD patients. This study was aimed atapplying this monocyte classification system to Crohn’s diseasepatients and determining any effect of the anti-TNFalphamonoclonal antibody infliximab on them.Methods: Blood was taken pre and immediately post infusionwith infliximab, and was processed to extract mononuclearcells. Monocytes were labelled using CD14 and CD16 antibodiesand analysed using flow cytometry.Results: See the table.

Number of total peripherally circulatingmonocytes (monocytes/mL)Healthycontrols(n = 16)

Pre-infusion(n = 7)

Post-infusion(n = 7)

P-value

All monocytes 150,253.50 41,257.14 18,514.29 <0.01Classical monocytes 104,837.08 25,177.69 8,206.95 0.01Intermediate monocytes 33,986.69 12,321.66 5,891.41 <0.01Non-classical monocytes 11,429.73 3,340.64 2,921.55 NS

(Control n = 16, pre and post infusion n = 7) P-value is pre- versus post-infusion. NS = not significant.

A paired sample t-test was carried out to show if the differencein total monocyte numbers pre and post infusion of infliximabwas significant. Results show that Crohn’s disease patientson treatment with infliximab have lower total monocytecounts than do healthy controls. Immediately after an infusionof infliximab, the numbers of classical and intermediatemonocytes, but not non-classical monocytes were significantlylowered compared to before the infusion.Conclusions: These results show that monocyte numbersare different between healthy controls and Crohn’s diseasepatients on treatment with infliximab, and that the drugselectively lowers certain monocyte sub-populations. Thesefindings are being expanded to include patients not infliximabtreatment, and patients with ulcerative colitis. In conclusion,monocyte sub-population analysis using flow cytometry mayprovide insights into disease pathogenesis and treatmentresponses.

P085Effect of phytoestrogenic dietary supplementation on theprogression of chronic intestinal inflammation to cancerin an animal modelM. Principi1 *, N. De Tullio1, K. Lofano1, M. Pricci1, M.P. Scavo1,G. Piacentino1, A. Contaldo1, V. Neve1, E. Ierardi2,M.C. Comelli3, A. Di Leo1. 1University of Bari, Bari, Italy,2University of Foggia, Italy, 3CM&D Pharma srl, Padova, Italy

Background: Colorectal cancer (CRC) is increased in inflam-matory bowel diseases (IBD). Chemopreventive agents couldminimize this risk. Estrogens exert prevention against CRCthrought Estrogen Receptor beta (ER-beta) with an inverserelation with the tumor. ER-beta induction may be a targetin CRC prevention. Phytoestrogens are dietary compounds withhigher binding affinity for ER-beta than ER-alpha. A blend of thedietary phytoestrogens (silymarin and lignan) and non-starchinsoluble fibers (Eviendep, CM&D Pharma) has been tested inan experimental mouse model of AOM/DSS induced colitis, toassess the anti-inflammatory and anti-carcinogenetic propertiesand to verify whether such effect is related to an increased ER-beta expression.Methods: A known model of dextran sodium sulfate/azoxy-methane induced CRC was used to obtain the best simulationof IBD-related CRC pathogenesis. Seventy-six C57BL/6J malemice were divided into three groups: 35 mice fed a Eviendep-modified diet during the whole carcinogenetic process, 35fed a standard diet (positive control) and 6 mice with notreatment or modified diet (negative control). Monitoringof colitis and tumorigenesis was performed by a specificvideo-endoscopic system (Coloview Miniendoscopic System) at21 weeks. Animals were sacrificed at 22 weeks for histogical andERs immunohistochemical evaluation. Histological score was: 0(no dysplasia), 1 (low grade dysplasia), 2 (high grade dysplasia)and 3 (carcinoma).Results: Mortality rate was of 40 50%. At sacrifice, treatedanimals showed a decrease in number/volume of polyps andin histological score (p < 0.05 ANOVA-Bonferroni post hoc test).Only 30% of Eviendep-supplemented mice showed at least1 CRC compared with the 100% of the positive controls.ER-alpha expression was higher in neoplastic tissue than innormal mucosa both in treated and positive control groups,while ER-beta labeling index (LI%) showed a higher valuein non-neoplastic tissue of the Eviendep-supplemented group(63.8±4.7) than in positive control (46.6±6.4), resulting similarto the ER-beta LI value of negative controls (54.9±7.9) (p < 0.05Fisher Exact Test).Conclusions: Our results suggest a chemopreventive effect ofEviendep on colonic carcinogenesis arising from inflamed tissue,and such an effect associates with an increase ER-beta contentin the tissue.

P086Donor dependent efficacy of human mesenchymal stromalcell treatment in experimental colitis

I. Molendijk1 *, V.L. van Zuijlen2, H.W. Verspaget1, W.E. Fibbe2,H. Roelofs2, D.W. Hommes3. 1Leiden University Medical Center,Gastroenterology and Hepatology, Leiden, Netherlands,2Leiden University Medical Center, Immunohematology andBlood Transfusion, Netherlands, 3University of California LosAngeles, Digestive Diseases, Los Angeles, United States

Background: Mesenchymal stromal cells (MSCs) are multipotentcells capable of differentiating into multiple cell lineages ofthe mesenchyme. They have both potent immunosuppressiveand tissue regenerative effects. In experimental colitis models,MSCs have shown positive effects on clinical endpoints. MSCsare also being explored in clinical trials as therapy for Crohn’sDisease.Methods: We compared the efficacy of human bone marrow-derived MSCs (hBM-MSC) in mild and severe experimental