Salivary calprotectin is elevated in patients with active inflammatory bowel disease

Abstract

Objectives: To assess the concentration of calprotectin, a heterodimer of S100A8 and S100A9 implicated in inflammatory bowel disease (IBD), in saliva of IBD patients compared to controls.

Methods: Unstimulated and stimulated saliva, and serum was collected from 23 IBD patients with active intestinal inflammation, verified by endoscopy. Fifteen patients were re-sampled after treatment. Saliva was collected from 15 controls for protocol validation and group comparisons. Calprotectin concentrations were measured by enzyme-linked immunosorbent assay, correlated to clinical data/indexes and routine laboratory parameters.

Results: Calprotectin was 4.0-fold (median) elevated in stimulated saliva of IBD patients compared to controls and tended to be elevated in unstimulated saliva (P = 0.001, P = 0.090). Crohn's (CD) patients had significantly elevated calprotectin in both unstimulated and stimulated saliva compared to controls (P = 0.011, P = 0.002). Newly diagnosed, treatment naïve CD patients had 8.2-fold (median) higher calprotectin concentrations in unstimulated saliva and 1.5-fold in stimulated saliva, compared to CD patients with established disease (P = 0.059, P = 0.019). Calprotectin decreased in serum of IBD patients after treatment (P = 0.011), and in unstimulated saliva of newly diagnosed, treatment naïve CD patients (P = 0.046, P = 0.028).

Conclusion: Salivary calprotectin is elevated in IBD, which suggests subclinical inflammatory responses in the oral cavity as a manifestation of IBD.

Keywords: Calprotectin; Inflammatory bowel disease; Saliva.