Tumor necrosis factor/cachectin in Crohn's disease. Relation of serum concentration to disease activity

Inflammatory mediators seem to be involved in the pathogenesis of Crohn's disease. Tumor necrosis factor is a primary mediator of inflammatory responses which causes metabolic effects related to tissue wasting. The aims of this study were to establish the presence of tumor necrosis factor in Crohn's disease patients, to determine of its serum levels reflect disease activity and to examine the relationship if this cytokine with other assessments of the activity of the disease. Serum concentration of tumor necrosis factor, measured with a biological assay, was significantly raised in 56 Crohn's disease patients (201 determinations) as compared with 44 controls (P < 0.0001). Patients with inactive disease had significantly lower tumor necrosis factor levels (3.58 +/- 0.55 ng/mL) as compared to patients with active disease (8.17 +/- 1.01 ng/mL). There was a significant correlation between serum tumor necrosis factor concentration and disease activity (r = 0.237, P < 0.002). Higher tumor necrosis factor levels were detected in patients with colonic involvement (ileocolitis and colitis) as compared with ileal localizations, and the difference was significant (t = 2.16, P < 0.05). Besides, it correlated negatively with albumin, haemoglobin and cholesterol.