P137 Salivary calprotectin: a potential biomarker in inflammatory bowel disease?

Abstract

Abstract Background Background: Biomarkers are used frequently for evaluation and monitoring of IBD. Fecal calprotectin (FCP) is an already established biomarker in IBD, nevertheless patients often do not feel comfortable with stool manipulation. A saliva sample collection is particularly interesting due to its noninvasiveness and readiness of collection. We aimed to assess if salivary calprotectin (SCP) could be used as a new biomarker to assess disease activity. Methods In this observational cohort study, saliva was collected through the passive drool technique from adult IBD patients. All patients were submitted to a previous oral examination performed by a dentist. Recent history of antibiotic treatment (within the preceding month), proton pump inhibitors or non-steroidal anti-inflammatory drugs were exclusion criteria. Determination of FCP and SCP levels was accomplished using Elia Stool Extraction Kit and Elia Calprotectin 2 test. Intestinal disease activity was assessed with fecal calprotectin levels and the Harvey-Bradshaw Index (HBI) or Partial Mayo score (PMS). Ethical approval was obtained. Results 92 patients (56 with CD and 36 with UC) were included. Clinical characteristics are presented in Table 1. Patients had a median FCP of 45 mg/Kg and a median SCP of 206.5 mg/Kg. No significant correlations between SCP and FCP, CRP (C-reactive protein), ferritin and ESR (erythrocyte sedimentation rate) were found. However, there was a significant correlation between fecal calprotectin and CRP (p<0.001) and ESR (p=0.011). Disease activity scores did not correlate significantly with SCP, although there was a significant correlation between FCP and PMS (p=0.006). IBD patients were stratified based on a composite criterion for inactive disease HBI score <5 for CD or a PMS ≤ 2 for UC, and FCP cutoff value of 150 mg/Kg), with no significant difference in SCP between the two groups, despite the significant difference in FCP (p<0.001). No significant differences between different treatments groups or no treatment in salivary calprotectin concentration were found using Kruskal–Wallis H tests (CD (χ2(4) = 6.211, p = 0.184; UC group (χ2(3) = 1.201, p = 0.753)). 77% of patients with IBD do not have periodontal health. Nonetheless, there was no significant difference in the median SCP value between patients with or without periodontal health. Although the median SCP value was higher in patients with UC without periodontal health, the difference was not statistically significant (0.484). Conclusion SCP does not correlate with FCP and do not represent a reliable biomarker to distinguish disease activity in patients with IBD patients. Moreover, according to our results, it cannot be used as a marker of lack of oral health, namely periodontitis.