Background: The destructive effects of oxidative stress has been proposed as a mechanism underlying the pathophysiology of Crohn's disease (CD). Lipid peroxidation induced by oxidative stress is indicated by malonylodialdehyde (MDA), glutathione (GSH) and ferric reducing ability of plasma (FRAP) as antioxidant systems protect from the pathological effects of free radical activity, and can limit the tissue injury. The aim of the study was to evaluate in serum, plasma and saliva the redox homeostasis based on lipid peroxidation factor MDA and antioxidants GSH and FRAP levels in patients with active and inactive CD and in healthy controls.
Methods: We enrolled 58 patients with CD (32 male, 26 female), age 18–63 years, 35 with active and 23 with inactive CD, and 25 age- and gender-matched healthy individuals. Patients with CDAI <150 were considered inactive, and patients with CDAI >150 were considered as active CD. Patients were chronically treated with azathioprine according to the ECCO guidelines. The blood samples (both serum and plasma) and unstimulated whole saliva were obtained in patients of the three groups, however, in patients with active CD samples were taken prior to the start of anti-inflammatory treatment. MDA, GSH and FRAP levels were measured in serum, plasma and saliva. Routine blood morphology and CRP levels in serum were also investigated in the hospital laboratory.
Results: MDA levels were significantly increased in serum (median: 12,174 nmol/g of protein), plasma (14.135 nmol/g) and saliva (28.051 nmol/g) in patients with active CD as compared to inactive CD and controls (respectively, 2.638, 2.851, 4,467 nmol/g; p<00001; Kruskal-Wallis test), and positively correlated with CDAI (r=0.740, p<0.0001; Spearman's correlation). GSH and FRAP levels were significantly decreased in serum, plasma and saliva in both CD groups as compared to controls, and negatively correlated with CDAI (GSH: r=−0.775, p=0.0001; FRAP: r=−0.800; p<0.0001).
Conclusions: Increased level of MDA and decreased levels of GSH and FRAP in patients with active CD and to lower extent in inactive CD as compared with healthy controls underline the importance of oxidative stress in the physiopathology of CD. Due to the high availability of saliva samples