Mirjam Majster [1], Sven Almer [2,3], Elisabeth A. Boström [1]

Affiliates

[1] Division of Oral Diseases, Department of Dental Medicine, Karolinska Institutet, Sweden. [2] Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden. [3] Division of Gastroenterology, Department of Gastroenterology, Dermatology and Rheumatology, Karolinska University Hospital, Stockholm, Sweden.

Abstract

Background
Calprotectin is clinically an established fecal biomarker of inflammatory bowel disease (IBD) activity. Urged by findings of oral involvement in IBD, we aimed to assess whether salivary calprotectin can aid in diagnosing and monitoring IBD.

Methods
Unstimulated and stimulated saliva, and serum was collected from 23 IBD patients (12 Crohn’s disease, 11 Ulcerative colits) with active intestinal inflammation verified by endoscopy. Fifteen patients returned 10-12 weeks after treatment escalation for re-sampling. 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, before and after treatment.

Results
Calprotectin concentrations were 3.1-fold elevated in stimulated saliva of IBD patients compared to controls and tended to be elevated in unstimulated saliva (P=0.001, P=0.090). CD patients had significantly elevated salivary calprotectin in both unstimulated and stimulated saliva compared to controls (P=0.011, P=0.002, Fig. 1 A,B). Further, newly diagnosed, treatment naïve CD patients had 4.1-fold higher calprotectin concentrations in unstimulated saliva and 1.8-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 saliva of newly diagnosed, treatment naïve CD patients (P=0.046, P=0.028). Yet, the change in salivary calprotectin correlated to the change in physician global assessment of disease activity.

Conclusion
Salivary calprotectin is elevated in IBD and a potential early marker of CD. This indicates ongoing inflammatory responses in the oral cavity during IBD.