Saliva Interleukin-6 in patients with inflammatory bowel disease.

Department of Clinical Biochemistry, Vejle County Hospital, Vejle, Denmark. abn@post9.tele.dk

OBJECTIVE: The inflammatory bowel diseases (IBD), Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory conditions that affect the gastrointestinal tract. In regulation of this inflammatory process, Interleukin-6 (IL-6) has a major role. Overproduction of IL-6 by immunocompetent cells contributes to development of the inflammatory condition. Elevated levels of IL-6 in saliva could be expected, because the saliva-producing cells are part of the digestive system. MATERIAL AND METHODS: IL-6 concentrations in saliva and plasma were studied in patients with CD (n=15), UC (n=7) and reference persons (RP) (n=19) by use of an ELISA method. RESULTS: A significant difference in saliva IL-6 concentration between CD patients (median 16.9 ng/L; p<0.05) and RP (median 6.3 ng/L) was found. A significant difference in plasma IL-6 concentration between CD (median 10.3 ng/L; p<0.001) or UC (median 7.8 ng/L; p<0.001) and RP (median 0.8 ng/L) was observed. In patients with CD, plasma IL-6 correlated significantly with C-reactive protein (CRP) as well as albumin. In patients with UC, saliva IL-6 and plasma IL-6 correlated significantly with AI (activity index) scores as well as albumin. In patients with UC, a significant correlation between the saliva and plasma IL-6 concentrations was found. CONCLUSIONS: IL-6 was found in saliva in patients with IBD, documenting the general involvement of the gastrointestinal tract extending to the mouth cavity, and measuring IL-6 may be an additional method for evaluating and monitoring the disease activity.

PMID: 16316893 [PubMed - indexed for MEDLINE]