LAUSR

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.