PHENOTYPIC ANALYSIS OF INTESTINAL NONINFLAMED MUCOSA IN CROHNS-DISEASE - EVIDENCE OF MONONUCLEAR CELL DEPLETION IN LAMINA PROPRIA

Objective: The objective of this study was to examine mononuclear cell subpopulations and evidence of cellular activation in unaffected jeju nal mucosa in Crohn's disease. Design: A cross-sectional study was per formed in patients with Crohn's disease from the ambulatory unity of t he University Hospital, UFRJ. Methods: Mucosal samples from 20 patient s with Crohn's colitis or ileitis were obtained by peroral jejunal bio psy. Patients with jejunal involvement or pregnant women were excluded from the study. Specimens were analysed histologically and by indirec t immunoperoxidase method using anti-monoclonal antibodies to CD2, CD4 , CD8, CD25, CD45RO, RFDR1; RFD1 and RFD7 by two 'blind' observers. Se ven patients with non-inflammatory bower disorders and two healthy vol unteers were studied as controls. Results: Lamina propria CD2-positive (CD2+) cells were reduced in Crohn's disease (P<0.004) whether clinic ally active (P<0.02) or clinically inactive (P<0.008). CD4+ and CD8+ c ells were also reduced in Crohn's disease (P<0.003), whereas the CD4:C D8 ratio did not differ from that in controls. CD25+, CD45RO+ and HLA- DR+ cells were not significantly increased in patients with Crohn's di sease. RFD7+ cells were decreased in Crohn's disease (P<0.02), whereas RFD1+ cells were not significantly different from the control group. Conclusion: No evidence of cellular activation was found in the unaffe cted mucosa of Crohn's disease. The reduction in T-cell and macrophage -like cell numbers may result from cell migration to inflamed areas. I t is also possible that this finding represents a primary defect which may have a role in the pathogenesis of Crohn's disease.