Alterations in glutathione peroxidase and superoxide dismutase activities in plasma and saliva in relation to disease activity in patients with Crohn's disease.

Crohn's disease (CD) is a chronic inflammatory condition with uncertain aetiology. Dysfunction of immunoregulatory factors and overproduction of reactive oxygen species (ROS) may contribute to the damage of the gastrointestinal tract. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) are involved in protection of cells from the damaging effects of ROS. The aim of the study was to assess activity of antioxidative stress enzymes, GPx and SOD, in plasma and saliva of patients with active and inactive forms of CD. Forty-seven patients with CD were prospectively enrolled in the study. The control group comprised 25 healthy volunteers. Patients' demographics, clinical features, localization of inflammatory changes, CD history, and treatment were recorded. SOD and GPx were assayed in plasma and saliva samples by ELISA method. CD activity index (CDAI) scores correlated inversely with SOD in plasma (r = - 0.46; P = 0.0012), but not in saliva. No correlations were observed in respect to GPx activities in both plasma and saliva and CDAI. Higher activity of plasma SOD was observed in patients with inactive CD in comparison with active CD (P = 0.004). No significant differences in SOD and GPx activity both in plasma and saliva were found between CD remission group and the control group. We concluded that in active CD the antioxidant defence system was diminished and returned to normal values in remission. Results of SOD and GPx assays in saliva are not conclusive, suggesting that saliva seems to be not an appropriate material for further similar studies.