Changes in whole saliva in patients with coeliac disease.

Many systemic diseases impair salivary flow rate and composition and therefore incite oral pathological processes. This study analyses the composition of whole saliva in patients with diagnosed coeliac disease (CD) and in healthy controls, and monitors possible changes in saliva composition after a short oral gluten challenge. Paraffin-stimulated whole saliva was collected from 128 CD patients and 55 healthy controls. In a separate study, paraffin-stimulated whole saliva samples were collected from 33 CD patients and 10 controls both before and 24 h after an oral mucosal and submucosal gluten challenge. No difference in saliva flow rate was observed, but total protein (P</=0.001), albumin (P</=0.001), IgA (P</=0.01) and IgG (P</=0.001) concentrations, as well as salivary peroxidase (P</=0.001) and myeloperoxidase (P</=0.001) activities, were significantly higher in CD patients than in healthy controls. The relative amounts of secreted proteins (mg/mg), e.g. amylase (P</=0. 001), total IgA (P</=0.005) and IgM (P</=0.001) were significantly lower in CD patients than in healthy controls. In CD patients, gluten challenge resulted in a decrease in myeloperoxidase (P</=0. 005) activity, IgA (P</=0.001) and IgM (P</=0.005) concentrations and the relative amounts of secreted IgA (P</=0.001). In healthy individuals, however, gluten challenge caused a decrease in total and relative amylase activity (P</=0.005; P</=0.001) and total IgM (P</=0.005) concentration. It is concluded that CD patients, following a strict gluten-free diet, secrete lower relative amounts of amylase, IgA and IgM into paraffin-stimulated whole saliva than do healthy controls.