Proinflammatory cytokines in the saliva of patients with active and non-active Crohn's disease

Abstract

Crohn's disease (CD) involves the entire gastrointestinal tract, including the mouth. Numerous cytokines play a role in the regulation of inflammatory process in CD. The aim of the study was to examine the prevalence of oral lesions in adult patients with CD and to investigate whether salivary concentrations of interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) are associated with the activity and oral manifestations of CD. A prospective study included 95 adult patients: 52 with active CD and 43 with inactive CD. The control group involved 45 subjects without CD. We performed blood tests, careful oral examination, and measurement of IL-1β, IL-6, and TNF-α in unstimulated whole saliva by enzyme-linked immunosorbent assays. IL-1β, IL-6, and TNF-α were significantly elevated in patients with active CD. IL-1β levels were 289.8 ±52.7 in patients with active CD vs. 196.7 ±42.9 pg/ml in patients with inactive CD (P <0.039), and 196.7 ±42.9 pg/ml (P <0.01) in controls. IL-6 levels were 13.8 ±4.2 vs. 7.2 ±3.1 pg/ml (P <0.041), respectively, and 6.3 ±1.4 pg/ml (P <0.001) in controls. TNF-α levels were 32.5 ±8.7 vs. 10.2 ±6.3 pg/ml (P <0.002), respectively, and 6.8 ±2.8 pg/ml (P <0.001) in controls. We observed CD-specific oral lesions: diffuse asymptomatic buccal swelling in 12 patients (23%) and cobblestoning in 5 patients (11.3%). CD-nonspecific lesions were observed in 17 patients (32.7%) with active CD, in 11 patients (25.6%) with inactive CD, and in 6 controls (13.3%). In active CD, higher salivary IL-6 and TNF-α and serum C-reactive protein levels correlated with specific oral lesions. In patients with active CD, salivary IL-1β, IL-6, and TNF-α levels are higher than in patients with inactive disease and controls. Elevated salivary IL-6 and TNF-α levels correlate with specific oral lesions. These cytokines may be used as markers of active CD, but the finding should be confirmed in a larger group of patients.