Introduction: 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.
Objectives: 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.
Patients and methods: 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.
Results: 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.
Conclusions: 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.