Complement activation capacity in plasma before and during high-dose prednisolone treatment and tapering in exacerbations of Crohn's disease and ulcerative colitis

Abstract

Background: Ulcerative colitis (UC) and Crohn's disease (CD) are characterized by intestinal inflammation mainly caused by a disturbance in the balance between cytokines and increased complement (C) activation. Our aim was to evaluate possible associations between C activation capacity and prednisolone treatment. Methods: Plasma from patients with exacerbations of UC (n=18) or CD (n=18) were collected before and during high dose prednisolone treatment (1 mg/kg body weight) and tapering. Friedman's two way analysis of variance, Mann-Whitney U test and Wilcoxon signed-rank sum test were used Results: Before treatment, plasma from CD patients showed significant elevations in all C-mediated analyses compared to the values obtained from 38 healthy controls ( p<0.02 ), and in mannan binding lectin (MBL) - concentration and MBL-C4-activation capacity (AC) values compared to UC patients (p<0.02). Before treatment, plasma from UC patients showed significant elevations only in the classical pathway-mediated C3-AC compared to values obtained from healthy controls (p<0.01). After treatment was initiated, significant reductions, which persisted during follow-up, were observed in the classical pathway-mediated C3-AC and MBL-C4-AC in plasma from CD patients (p<0.05). Conclusions: Our findings indicate that C activation capacity is up-regulated significantly in plasma from CD patients. The decreases observed after prednisolone treatment reflect a general down-regulation in immune activation. © 2005 Zimmermann-Nielsen et al., licensee BioMed Central Ltd.